Medical Glossary Terms
After-birth
The placenta and associated membranes passed from the uterus
after birth of the child. The placenta usually follows shortly after the baby.
However, if it does not come on its own the doctor may have to remove it by
other means, as complications may arise if it is not expelled. The foetal
membranes - the chorion is the outer one and the amnion is the inner one -
envelope the embryo and contain the amniotic fluid.
Alpha-fetoprotein screen
(AFP)
A plasma protein normally produced by the foetus' liver. AFP
eventually finds its way into the mother's blood and the amniotic fluid. When
too much or too little AFP enters the mother's blood stream it can be a sign of
foetal problems, such as birth defects. High AFP levels in the mother's blood
indicates an increased risk of foetal spina bifida, anencephaly, or other malformations. Low AFP levels are
associated with an increased risk of Down syndrome
(trisomy 21) and other chromosomal problems. Measuring the AFP level is not
sufficiently accurate in screening for Downs- AFP testing should be combined
with other tests. Don't assume your child has Down syndrome or spina bifida just
because you had an abnormal AFP test result. The AFP test assesses risk, it does
not diagnose disease. Unfortunately, many abnormal test results are falsely
abnormal and do not reflect a problem with the foetus or mother. If the AFP test
is abnormal, additional testing should be performed.
Amniocentesis
Sometimes called an
'amnio', this minor surgical diagnostic test allows the doctor to obtain a
sample of the amniotic fluid. The amniotic fluid is then analysed to look for
genetic characteristics of the baby or to check on the maturity of the unborn
baby’s lungs. The amniocentesis is a common way to obtain material for genetic
and other testing of the baby. The doctor inserts a long, thin, hollow needle
through the mother's abdomen into the uterus and amniotic fluid. Usually the
doctor uses ultrasound imaging to guide the needle. The small amount of fluid
removed should not affect the baby. The risk of complications from the procedure
is low, but, as with any procedure, complications can occur. Be sure to consult
with your doctor before the procedure is performed.
Amniocentesis helps the doctor estimate the baby's lung maturity. Because
babies often 'breathe' amniotic fluid in and out of their lungs inside the womb,
the amniotic fluid is chemically similar to the fluid within their lungs. As
their lungs mature, the chemical composition changes. These changes can be
measured from the amniotic fluid and used to estimate the maturity of the
lungs.
Amnion
The thin, transparent inner membrane (the
chorion is the outer layer) that constitutes the amniotic
membranes. These membranes contain the amniotic
fluid and form a protective layer for the baby insulating him/her from
bacteria in the vagina. Rupture of this sac exposes the child to bacteria in the
vagina and increases the risk of infection if the infant is not delivered within
about 18 hours. Labour usually starts shortly after or before rupture of the
amniotic membranes.
Amniotic
fluid
Amniotic fluid is fluid inside the membrane that forms a sac
around the embryo and later the foetus. The foetus and the placenta produce the
amniotic fluid. This buoyant fluid helps the foetus grow uniformly, helps the
bones and muscles develop, and allows the baby to move within the uterus. Babies
breathe this fluid in and out of their lungs in the womb helping the lungs to
grow as well. It also keeps the amnion (membrane) from
sticking to the foetus.
Having too little or too much amniotic fluid can signal a problem with the
foetus or the mother. A mild decrease in amniotic fluid is common late in
pregnancy. Too much amniotic fluid may cause the uterus to enlarge, which may
result in premature labour. Excess fluid occurs in maternal diabetes, twins and
some other conditions. Foetal problems that may also result in excess fluid are
esophageal atresia (blockage of the esophageus that prevents effective
swallowing) which prevents the amniotic fluid from passing to the stomach and
intestines for absorption.
Amniotomy
Amniotomy -
Intentional rupturing of the amniotic sac to hasten or induce labour. This
procedure is also done to check for meconium or to allow
the doctor to use an internal foetal monitor.
Although an amniotomy can speed up labour, its disadvantages are that it can
rarely lead to umbilical cord compression, and
it eliminates the barrier that protects the foetus from bacteria in the birth
canal. Some doctors frequently perform an amniotomy and some do not.
Analgesic
Refers to any
medication that relieves pain while allowing the patient to remain
conscious.
Anencephaly
Birth defect characterised by
failure of the brain and skull to form properly. Parts of the brain and the
skull may be missing. This is one of several neural tube defects (NTDs). The
neural tube is an embryonic structure in the developing foetus that forms the
spinal cord and brain. Anencephaly occurs when the upper end of the neural tube
(the rostral neuropore) fails to close in the embryo's fourth week of life. This
is a fatal malformation and these children usually die within a few days of
delivery. The risk of anencephaly and other NTD's can be reduced by taking
appropriate amounts of folic acid before conception and throughout
pregnancy.
Anterior
Means in front of,
usually with reference to the front part of the body. Often used in association
with the term'anterior presentation' or 'occiput anterior' (OA). Usually, babies
are born with the back of the head or occiput pointed up or slightly to the left
or right side. It is as if the child was looking at the floor during emergence
from the birth canal. This is the best position in most cases since it allows
the child to negotiate more easily the turns required to get through the
mother's pelvis and birth canal. If the baby presents in the birth canal with
the occiput anterior and to the left it is called an LOA (left occiput anterior)
presentation. If the occiput is anterior and to the right, it is called ROA
(right occiput anterior).
Apgar score
A
numerical summary of a newborn's condition at birth based on the five signs
noted in the table. The score is measured at 1 and 5 minutes. Additional
measurements are made every five minutes thereafter if the score is <7 at
five minutes until the score reaches 7 or greater. Prematurely born infants
generally have lower scores than full term infants. The Apgar score does not
predict future development with accuracy. The score was developed by Virginia
Apgar and represents a rough estimate of the condition of the infant at birth.
Asymptomatic
Without
symptoms.
Back labour
Some
women have labour pains that are concentrated in their back. This is more common
when the baby is presenting in the birth canal with the occiput posterior (OP)
with the baby looking up rather than down as in the occiput anterior (OA)
position.
Bilirubin
Yellow chemical
that is a normal waste product from the breakdown of haemoglobin and other
similar body components. The placenta clears bilirubin from the foetus' blood,
but after delivery this task belongs to the infant. It usually takes a week or
more for the newborn's liver to adjust to its new work load. When bilirubin
accumulates, it makes the skin and eyes look yellow, a condition called
jaundice. A little jaundice can be expected in all newborns. If the jaundice is
higher than usual, it can usually be treated with phototherapy (special lights).
If the level of bilirubin gets extremely high, brain injury is a risk. With
modern treatment techniques such as phototherapy, such dangers rarely occur.
Phototherapy is so effective in helping the liver excrete bilirubin that
elevated levels are rarely a problem. Prematurely born infants may have elevated
levels of bilirubin for several weeks.
Biophysical
profile
A series of measurements made to evaluate the foetus'
condition before delivery. The biophysical profile is similar to the Apgar
system, but performed before delivery. Ultrasound observations are made for at
least 30 minutes. The score is based on the findings in the table below.
Birth canal
The tunnel comprised of the
vagina and cervix, through which the infant must pass from
the uterus during birth.
Bloody show
As the cervix dilates, blood and the cervical mucous plug (from the
cervical canal) pass from the vagina. The bloody show is a classic indicator of
beginning or progressing labour.
Bradycardia
An abnormally low heart rate.
When referring to the foetal heart rate (FHR) tracing in labour, abnormally low
heart rates can signal problems with the foetus before delivery. The FHR is
often monitored for abnormalities of the heart rate. Foetal bradycardia episodes
are sometimes called FHR decelerations. Some types of FHR decelerations are
common during labour. Others suggest foetal stress and demand further evaluation
or intervention. Sometimes the FHR not only dips down, it stays down and does
not return to its usual level. This is an ominous situation that demands
immediate delivery. FHR decelerations or bradycardia episodes come in three
types.
- Early decelerations are normal and common. These decelerations are called
early because they occur early during a uterine contraction. These FHR decelerations usually occur after
labour is well established (4-7 cm of cervical dilatation). The FHR rarely goes
below 100 beats per minute. The cause of these decelerations is head compression
during uterine contractions.
- Late decelerations cause more concern. They are called late because they
first appear at or after the peak of the uterine contraction. The FHR improves
only after the contraction has stopped. These FHR decelerations may be mild or
severe based on how low the FHR goes and how long it takes for the FHR to
recover. It is thought to be caused by reduced blood flow to the uterus and
placenta during a contraction.
- Variable decelerations are a common type of FHR deceleration in labour and
are caused by umbilical cord compression. Up to 80% of foetuses will have
variable decelerations during labour. The significance of the these
decelerations depends on how low the heart rate drops and how long the episode
lasts. When referring to a newborn baby bradycardia is usually associated with
apnoea or cessation of breathing. Apnoea and bradycardia spells are most common
in prematurely born infants. During these spells the infant will stop breathing
for at least 15 seconds and the heart rate will start to slow. Gentle touching
or other stimulation almost always restarts the breathing and increases the
heart rate. Medications (theophylline or caffeine) are often used to treat these
spells in newborn babies. Apnoea of prematurity does not cause sudden infant
death syndrome (SIDS). However, prematurely born babies are at greater risk for
SIDS, just because they are prematurely born. The exact reasons why premature
babies have a higher risk of SIDS is not known.
Braxton-Hicks
contractions
Periodic contractions of the uterus that do not
represent true labour. These contractions may begin as early as the first
trimester, are irregular, usually painless, and of low intensity. They can be
confused with labour. Toward the end of the third trimester, the contractions
become more frequent and intense.
Breech presentation
When babies
are aligned in the uterus to come out buttocks first, as opposed to head
first--the way most babies come out of the uterus --it is called a breech
presentation. The head is the largest part of a full term baby's body.
Therefore, delivery of the buttocks first may not adequately open up the birth
canal enough for the head to pass through. The head may then get stuck in the
birth canal, leaving the infant and mother in a precarious situation. Most
babies with a breech presentation are delivered by caesarean section. On occasion the infant can be
turned around so that he is lined up to come out head first.
Caesarean section
Delivery of the
baby through an incision in the abdominal and uterine walls when delivery
through the birth canal is impossible or dangerous. This procedure was performed
as early as 715 BC and can be lifesaving for both the infant and the mother in
certain situations. However, elective caesarean sections (those scheduled in
advance and performed before a woman goes into labour) when performed before
term are a significant cause of medical problems in the baby. If a caesarean
section is performed before the infant's lungs have completely matured, the
infant may have serious respiratory problems. Elective caesarean sections would
normally be performed only if there is good evidence that foetus has mature
lungs. Women should be evaluated using methods to make sure that the foetus'
lungs are mature. The criteria are as follows:
- Foetal heart tones should have been documented for 20 weeks by
non-electronic fetoscope or for 30 weeks by Doppler.
- It has been 36 weeks since a positive serum or urine chorionic gonadotropin
pregnancy test was performed by a reliable laboratory.
- An ultrasound measurement of the crown-rump
length, obtained at 6-11 weeks, supports a gestational age of at least 39 weeks.
- An ultrasound, obtained at 12-20 weeks confirms the gestational age of at
least 39 weeks determined by clinical history and physical examination.
An alternative method to assure foetal lung maturity is toperform an amniocentesis and measure chemicals in the amniotic
fluid. The concentrations of these chemicals are a good reflection of lung
maturity status.
Caput succedaneum (caput)
A
spongy swelling and accumulation of fluid in scalp tissues of infants born
vaginally. This occurs because the baby's head, in normal presentation, is under
much pressure in the birth canal, This pressure on the skin of the scalp causes
accumulation of soft tissue fluid. Although it may look serious, it usually
disappears within a few days.
Cephalopelvic
disproportion
The most common reason for doing a caesarean section. Sometimes the infant's head is
larger than the mother's pelvis, through which the head must pass in a vaginal
delivery. Therefore, the safest way to deliver the infant is to do so by
caesarean section. There are several ways to estimate foetal size and pelvic
size. Physical exam and ultrasound are very useful in evaluating cephalopelvic
disproportion.
Cervical gel
This usually refers to a
prostaglandin medication that is prepared in a gel-like material. It is placed
on the cervix to hasten cervical dilatation in preparation
for delivery.
Cervical incompetence
Inability
of the cervix to remain closed during pregnancy. The properly functioning cervix
will be tightly closed until labour to keep the foetus safely inside the
uterus. Some women have a cervix that does not stay closed and opens up in the
second or early third trimester. This can result in miscarriage of the pregnancy or premature delivery of
the baby. To avoid premature delivery with an incompetent uterus the cervix may
be stitched up or the mother may be confined to bed. The reason for many of
these cases is not known. However women who were exposed to diethylstilbestrol (DES) as a foetus or
those who have had removal or cauterisation of cervical tissue may be at
increased risk for this.
Cervicitis
Inflammation of the cervix.
Cervix
The lower portion of the uterus. The cervix is the part of the uterus that keeps the
foetus from falling out of the uterus. During labour, the
cervix thins and dilates to permit passage of the infant out of the uterus and
into the vagina.
Chorioamnionitis
Infection, of the chorionic and amniotic membranes caused by bacteria. These
membranes enclose the amniotic fluid and when
infection is present in the membranes, the mother and foetus are at increased
risk for severe infection. When chorioamnionitis occurs, delivery of the foetus
should be undertaken without delay. The infection is very difficult to treat
without delivery of the foetus. Chorioamnionitis can also cause premature labour.
Chorion
The outermost layer of
the two foetal membranes, which envelope the growing foetus and serves as a
protective barrier to the foetus against infection.
Chorionic villus sampling
A
prenatal diagnostic test, done at 8-10 weeks of pregnancy to asses the foetus'
chromosomes. The advantage of this test over amniocentesis is that (CVS) can be done earlier in
gestation than the amniocentesis. However, the risks to the foetus are greater
than with amniocentesis. Chorionic villi are a part of the placenta but contain
foetal tissue. A needle is inserted into the chorionic villi of the placenta and
a small amount of tissue is removed and sent for analysis. The placenta can be
approached either through the cervix or through the mother's abdominal
wall.
Chromosome problem
Also called
chromosomal malformations, anomalies, or defects. This refers to abnormalities
in the number or organisation of chromosomes. A common example is trisomy 21 or
Down syndrome, in which there is an extra
chromosome number 21. This extra chromosome results in a constellation of
abnormalities that is usually recognizable at birth and consistent from one
patient with Down syndrome to another.
Circumcision
Removal of the prepuce or
foreskin covering the penis. There has been a lot of controversy about this
procedure in the past few years. Some believe that it is medically beneficial
while others disagree. There are repeated studies showing that urinary tract
infections are less common in circumcised boys. However, urinary tract
infections are relatively rare in boys anyway. There have also been studies of
sexual function in circumcised and uncircumcised males with very few differences
found between the two groups. In some populations, circumcision reduces the risk
of contracting AIDS. Penile cancer (also a very rare disease) is also less
common among circumcised men.
Contraction
Almost always refers to the
contracting of the muscles of the uterus during labour.
The uterus contracts in an effort to expel the foetus into and out of the birth
canal. Contractions are usually a sign of labour, although they can occur before
labour, see Braxton Hicks
contractions.
Contraction stress test
A
test of uteroplacental function. Uterine contractions are initiated with Pitocin and the foetal response to the contractions is
analysed as a measure of foetal well being.
Cord blood banking
Storage of
blood from the umbilical cord. Blood in the
umbilical cord is rich in blood cells that are able to replenish the bone
marrow. Freezing cord blood cells immediately after delivery preserves these
cells should the baby need a bone marrow transplant in the future. It is not now
clear that this should be done or how useful these cord blood specimens will be
in the future. The potential usefulness of cord blood is the object of much
ongoing research.
Cord compression
Squeezing of the umbilical cord during pregnancy, labour or delivery.
Pressure on the umbilical cord reduces blood flow from the placenta to the
foetus. If prolonged pressure is applied, it can produce a dangerously low level
of oxygen in the foetus.
Crowning
The stage in childbirth when the top
of the infant's head becomes visible at the vaginal opening.
Delivery room
The room where the
delivery occurs. In the past pregnant women routinely laboured in one room and
then were moved to a delivery room where the baby was actually
delivered. Following delivery, the mother would then be moved to a recovery
room. To prevent these cumbersome moves, many hospitals have now changed to a
combination labour, delivery and recovery room (called the LDRP). This prevents
having to move the mother to another room at the height of labour pains, just
before delivery.
Demerol
Meperidine hydrochloride (Demerol),
either alone or in combination with promethazine hydrochloride (Phenergan), has
the advantage of a history of extensive use in labour. Common dosing is 50 to
100 mg of meperidine and 25 to 50 mg of promethazine IM every 3 to 4 hours. Both
medications can be given IV, but at reduced dosages of 25 to 50 mg of meperidine
(diluted to 10 mg/mL) and 25 mg of promethazine. Since metabolic by-products of
meperidine may have half-lives of 8 to 21 hours and will accumulate in patients
with renal impairment and in their premature foetuses and neonates, the
risk-benefit ratio requires re-evaluation before repeated dosing. The
manufacturers recommend giving no more than 100 mg of promethazine during 24
hours of labour.
Diethylstilbestrol (DES)
A
synthetic, non-steroidal oestrogen that was prescribed to many women up until
the early 1970s. It was thought to prevent or treat problems with pregnancy.
However, female foetuses who were exposed to DES developed serious problems in
their reproductive organs when they became adults. About 1/4th of exposed women
develop anatomical problems with their cervix or vagina. Examples of these are
underdeveloped cervix, small uterine cavities and abnormal fallopian tubes.
These women are also more likely to have ectopic
pregnancy, preterm labour, miscarriage and incompetent cervix. Women whose mothers took DES
during pregnancy should mention this fact to their obstetrician so that
potential problems can be identified and treated.
Dilation
Opening up, enlargement of a tubular
structure. This usually refers to the cervical dilation that occurs during
labour. The opening of the cervix must go from essentially 0 centimetres to
about 10 centimetres, the usual size required for the baby to pass through the
cervix, which forms part of the birth canal. The first
stage of labour is that part of labour during which the cervix dilates up to 10
cm or is completely dilated. This usually takes several hours and is shorter
with subsequent pregnancies.
Doppler ultrasound
A special form
of ultrasound that uses sound waves to measure the velocity of blood flow.
Doppler ultrasound can be used to listen to the foetal heart beat, examine the
foetal heart for defects, and estimate placental blood flow.
Down syndrome
A condition that has a
specific set of characteristics found in children who have an extra number 21
chromosome. Another name for this condition is trisomy 21. Characteristic
findings are widely spaced first and second toes, a single hand (simian) crease,
short fingers, a fold of tissue (epicanthal fold) across the inner aspect of the
eye (near the nose), eyes that slant upward, decreased muscle tone, flattened
back portion of the head, and a protruding tongue. The only way to make the
diagnosis with certainty is to perform a chromosomal analysis either before
birth (chorionic villus sampling or amniocentesis) or after birth (blood or tissue
chromosomal analysis). The range of outcomes for these children is quite broad
and many function quite well, although very few have normal intelligence.
The risk of a healthy woman having a child with Down's syndrome increases
with maternal age, as follows:.
Age Risk of Down’s syndrome
- 25 years 1 in 1300
- 30 years 1 in 900
- 35 years 1 in 350
- 40 years 1 in 100
- 45 years 1 in 25
- 49 years 1 in 12
Dystocia
Literally, it means difficult labour
and practically means abnormally slow progress of labour. The word comes from
the Greek 'dys' meaning 'difficult, painful, disordered, abnormal' and 'tokos'
meaning 'birth'. Four potential factors may cause difficult labour characterised
by abnormally slow progress. They may occur separately or together.
- Uterine contractions may be either too weak or too uncoordinated to open up
the cervix. There may also be inadequate pushing with voluntary muscles during
the second stage of labour.
- The baby may be lined up wrong to easily pass through the birth canal.
Alternatively, there may be other problems with the baby that also retard
passage of the baby through the birth canal.
- The maternal bony pelvis may be too narrow to allow the baby to pass through
the birth canal.
- Abnormalities of the birth canal other than those of the bony pelvis may
obstruct foetal descent.
The most common cause of dystocia is a small bony pelvis and/or
insufficiently strong and coordinated uterine contractions.
Ectopic pregnancy
Pregnancy in
which the embryo develops outside of the uterus. Normally,
conception occurs not in the uterus but in the fallopian tubes. The fertilised
egg then moves down into the uterus where it should implant in the lining of the
uterus. When the embryo implants anywhere else other than the uterine lining it
is called an ectopic pregnancy. As the embryo grows outside of the uterus it is
usually in a confined space, such as the fallopian tube. Eventually, the embryo
enlarges the tube to the point of rupturing the fallopian tube, which causes
haemorrhaging. This haemorrhaging can be so severe as to cause shock and death.
Surgery is required to remove the misplaced, embryo. The embryo itself is
usually normal and would have continued to develop normally had it implanted in
the uterus, rather than the fallopian tube or other abnormal location.
Losing a child through an ectopic pregnancy can be very emotionally
traumatising. A woman who has lost a pregnancy due to ectopic location needs the
same support as women who have lost pregnancies through miscarriage and other
causes.
Ectopic (in the wrong place) pregnancy is the leading cause of maternal
mortality in the first trimester and is a true emergency. Fortunately, the
incidence remains very low. Symptoms of ectopic pregnancy include abdominal
pain, missing a normal period, intermittent or scanty vaginal bleeding, shoulder
pain, weakness, dizziness, and fainting. Significant abdominal pain (anywhere in
the abdomen) in the first trimester should be reported to your doctor.
Effacement
Thinning of the cervix that occurs in preparation for childbirth. The
cervical canal shortens from 2 cm to paper thin edges and the canal itself
disappears. Only the external opening of the uterus remains of what was the
cervix. The edges of the internal opening of the cervix are drawn upward several
centimetres to become a part of the lower uterine segment. When the cervix
becomes as thin as the adjacent lower uterine segment, it is considered to be
completely effaced.
Electronic foetal
monitor
An electronic device that is used to monitor the heart rate
of the foetus before delivery. The electronic foetal monitor is usually used in
labour and can identify foetal problems before delivery. There is some evidence
that monitoring the foetal heart rate electronically may increase the rate of
caesarean delivery. Most obstetricians believe that it identifies serious foetal
problems earlier than other methods, thus improving outcome. Another method for
monitoring the foetus' health during labour is listening to the foetal heart
beat with a special foetal stethoscope or Doppler ultrasound device at regular
intervals. There are two types of foetal monitors:
- External, which are attached to the mother's abdomen.
- Internal, which attach to the infant's scalp inside the uterus.
Engagement
Refers to the point in
labour/delivery at which the baby's head, or other presenting part (buttocks in
a breech presentation), begins to descend through (engage) the pelvic canal.
Epidural
The epidural is situated over the
dura matter. The dura is a tough, fibrous, whitish membrane; the outermost of
the 3 membranes covering the brain and spinal cord. The extradural is located
outside of the dura matter.
Epidural block
An anaesthetic
technique that reduces pain during childbirth without altering the mother's
level of consciousness. This type of regional anaesthesia is often given during
labour to relieve the pain of contractions and delivery. A needle is inserted
through the skin of the back into the epidural space. Anaesthetic is then
injected around the spinal cord anaesthetising the nerves of the lower part of
the body. A well-placed epidural block provides excellent pain relief. A
potential disadvantage is a reduction in a woman's ability to push the baby out
of the birth canal. Some people feel that the use of an epidural block may
increase the likelihood of a caesarean section.
The epidural block may also lower a woman's blood pressure, affecting blood flow
to the baby. However, in the hands of alert, experienced personnel, the risks of
an epidural are low.
Episiotomy
A minor surgical procedure which
widens the birth canal by cutting the introitus (vaginal opening). Episiotomy is
performed to prevent the jagged, less controlled tearing of the introital tissue
during the stretching associated with delivery. The routine use of an episiotomy
may cause more problems than it solves and has been linked to increased rectal
tearing. It is a painful procedure that may predispose to infections and other
complications. An episiotomy may be very helpful when forceps or vacuum
extraction are used and with breech presentations. Talk to your doctor about
whether you might need one. The use of episiotomies has decreased in the past
few years.
External cephalic
version
Turning the baby so that the head is pointed down toward the
pelvic inlet. In most pregnancies, babies orient themselves with the head down
toward the pelvis in preparation for labour and delivery by about the 34th week.
If the baby is oriented with the head up or lying with the back toward the
pelvis, labour is more complicated and a caesarean delivery is more likely. Your doctor may
try to turn the baby before delivery- this is called an external version. The
doctor will try to turn the baby so that the head is down, pointing toward the
pelvis. This is done with pressure on the baby applied through the mother's
abdomen. External cephalic version reduces the necessity of a caesarean section,
but is not indicated in every case of breech
presentation. Ask your doctor more about version to see if this procedure is
appropriate for you. There are both risks and benefits from this procedure.
Fetoscopy
Use of a special, fibre optic,
tubular telescope to look at the foetus while it is still in the mother's
uterus. Use of this scope requires a tiny incision in the mother's abdominal
wall so that the telescope can be passed into the uterus to directly view the
foetus. Technically, listening to the foetal heart rate with a fetoscope, a
special type of stethoscope is also fetoscopy.
Foetal distress
Problems with the
unborn child during labour. Sometimes during labour and delivery the foetus may
not get enough oxygen from the placenta and may become 'distressed'. When this
happens, the foetal heart rate may show patterns consistent with oxygen
deprivation. These patterns can been seen on the foetal heart rate monitor. They
alert the obstetrician that further investigation or intervention is needed to
assure the foetus' well-being.
Foetal monitoring
Monitoring of the
baby before birth. This usually refers to monitoring of the foetal heart beat.
There are two ways to do this. Before the mother's membranes have ruptured
(water has broken) a belt containing a receiver similar to an ultrasound can be strapped to her abdomen and used to
monitor the foetal heart rate and uterine contractions. After the membranes have
ruptured and the cervix has dilated, an internal monitor
can be attached directly to the baby's scalp. There are other tests that can be
used to monitor the foetus during and before labour such as ultrasound, scalp pH
measurements, and others.
Foetal presentation
The part of
the foetus that enters the birth canal first. When the head enters the birth
canal it is called a vertex presentation. When the buttocks present first it is
called a breech presentation. There are
several methods used to diagnose foetal presentation: abdominal palpitation,
vaginal examination, locating the foetal heart beat on the abdomen, and
ultrasound scans. At or near term 96% of babies are in a vertex position, 3.5%
are in a breech presentation, 0.3% in a face presentation, and 0.4% are in a
shoulder presentation. About 2/3 of vertex presenting babies are in a left
occiput anterior (See Anterior.) and 1/3 are in a right
occiput anterior position. Up to 14% of babies are in a breech presentation
until the 29th-32nd week of gestation. Many of these babies change to a vertex
presentation birth.
Foetus
The name given to the embryo after the
8th week. Technically this name should be used until the baby is completely
outside of the mother's body.
Fontanelle
Soft spots found between the
cranial bones of the newborn’s skull. There are two fontanelles that are usually
examined in the newborn period, the anterior and the posterior fontanelles.
Footling
presentation
Presentation with the feet entering the birth canal
ahead of any other part of the body. This may occur with two feet (double
footling) or a single foot (single footling). Most often one leg is extended
while the other is flexed at the knee. It is usually safer to deliver this kind
of baby by a Caesarean section early in labour
or before labour begins rather than vaginally. If a footling breech is delivered
vaginally, there is a risk that the head may not easily through the birth canal.
Forceps delivery
A delivery in which
forceps are used to help assist the baby from the birth
canal. Forceps are a two-bladed instrument that could be compared to a pair
of kitchen tongs in design. Forceps have the additional feature that the two
blades are easily taken apart to facilitate placement on the baby within the
birth canal. After placing the two blades on the baby's head, the doctor
reconnects the two blades and then uses the forceps to apply traction to the
infant, assisting delivery. The forceps are not sharp, but they firmly grasp the
baby's head. Forceps may be used for several different reasons: to shorten the
second stage of labour, end an abnormally long second stage, when the foetal
heart rate suggests problems, when the mother suffers from cardiac disease, or
whenever the health of the mother and baby are declining and a speedy delivery
is required. Although once used often, they are almost never used now.
Gestational age
Baby’s age in weeks
from the first day of the mother’s last menstrual period before delivery. The
duration of a pregnancy is measured by gestational age. Gestational age is
basically a measure of the length of time that a baby spends in the womb. It is
generally calculated as the time from the first day of the last menstrual period
to the day of birth. Conception occurs on about day 14 after the first day of
the last menstrual period. However, this date is not usually known. The first
day of the last menstrual period usually is known. Therefore the beginning date
for the pregnancy is the first day of the last menstrual period.
A normal gestation lasts 40 weeks or 280 days. If delivery occurs before 37
weeks gestation, the baby is considered prematurely born. By this definition,
about 11% of all babies are born prematurely. Irregular menstrual periods or
first trimester vaginal bleeding can confuse gestational age estimates. To
improve the accuracy of gestational age estimates, many doctors use an
ultrasound examination before about 20 weeks gestation. Ultrasound findings help
your doctor confirm or correct the gestational age estimate.
Hernia
An abnormal bulging or protrusion of
tissue or an organ through an abnormal opening. The most common type of hernia
is an inguinal hernia. It is seen more often in boys, but it can be present
occasionally in girls. The testes develop inside the abdomen and migrate through
the inguinal canal and into the scrotum. The inguinal canal is the passageway
from the abdomen into the scrotum and is bounded by membranes and muscle. When
the inguinal canal does not completely close or re-opens, intestine can travel
down the passageway and a hernia develops.
In most full-term babies the inguinal canal seals over before birth. In
prematurely born infants, the canal is opened by the pressure of the baby crying
and the increased abdominal pressure associated with feedings and life outside
the uterus. The incidence of hernias is about 15 percent among prematurely born
infants. It may be higher in those who are extremely premature.
The only way to correct a hernia is to surgically repair it. The anaesthesia
risks of the procedure are lessened if repair is delayed until about five months
of age; however, hernia repairs are often performed in infants at much younger
ages, if necessary, without complications. For some infants a combination of a
local and spinal anaesthetic can be used instead of general anaesthesia. This
combination of anaesthetics reduces the risk of apnoea following anaesthesia and
surgery.
Humid-crib
Incubator (plastic box that is
heated and sometimes humidified). It provides a warm, protected environment for
premature babies who are often not able to maintain their own temperature
because of their small size and body mass.
Incompetent cervix
Painless
cervical dilatation in the 2nd trimester often followed by premature delivery of
the foetus. This can sometimes be diagnosed early on with the use of an ultrasound. The only real treatment is a surgical
procedure called cerclage, which reinforces the cervix with sutures. An
alternative to surgery is bed rest, but this is not always effective. Possible
complications to cerclage are bleeding, contractions, and ruptured membranes,
but if done by the 18th week these risks are decreased. The success rate is
about 85-90%. If an incompetent cervix is not properly treated it will cause
problems with each subsequent pregnancy.
Induction
If labour has not started at an
appropriate time or if there are maternal indications for delivery before labour
starts naturally, medications may be used to initiate labour. Prostaglandin gel
and oxytocin (Pitocin®) are the most common medications.
Rupture of the amniotic membranes may also hasten the onset of active
labour.
IUPC (intrauterine
pressure catheter)
A catheter inserted into the uterus during labour to measure the actual pressure within
the uterus. These measurements are important in measuring the frequency and
intensity of uterine contractions. The foetal heart
rate is usually measured simultaneously. The combination of these measurements
facilitates the evaluation of labour and foetal well-being.
Lamaze
The oldest, most common technique for
reducing the stress and pain of labour and delivery. Lamaze trains women to
replace unproductive behaviour during labour and delivery, such as anger and
screaming, with more productive actions, such as relaxation and deep breathing.
Emphasis on relaxation and breathing make pushing more effective and less
painful.
Meconium
Dark green, sticky mucus normally
found in infants' intestines. It is the first stool passed by the newborn.
Meconium is a mixture of amniotic fluid, bile and
secretions from the intestinal glands. Passage of meconium within the uterus
before birth can be a sign of foetal distress.
Meconium is very irritating to the lungs. If there is a possibility that an
infant may have thick meconium in the lungs, the doctor inserts a tube into the
trachea and suctions out the loose meconium. This tube, called an endotracheal
tube, can also be used to help an infant breathe after the meconium has been
removed.
Miscarriage
Spontaneous abortion or loss of
the foetus before 21 weeks of gestation. Habitual abortion
is defined as the spontaneous loss of 3 or more consecutive pregnancies.
Habitual or recurrent abortion is a form of infertility. Couples who have had 2
or more miscarriages (spontaneous abortions) have about a 5% chance that one
member of the couple is carrying a chromosome
problem that is contributing to the miscarriages. A considerable proportion
of pregnancies end in miscarriage.
Molding
The creation of shape, or fashioning of
an object. Usually refers to the newborn's head that is moulded by passage
through the birth canal during vaginal delivery. The
head takes on a pointed shape that quickly returns to normal after a few days.
The brain is very plastic and tolerates this molding well.
Mucus plug
A plug of mucus that fills the
cervical canal during pregnancy. Discharge of the plug is usually followed by
rupture of the membranes and progressive labour.
Natural childbirth
The process of
giving birth without anaesthesia or medication to relieve pain. Natural
childbirth is not possible for everyone, if you would like to experience a
natural childbirth discuss this with your doctor.
Neonate
The name given to a newborn infant for
the first four weeks after birth.
Neonatologist
Doctor who specialises in
the care of sick newborn babies. Physicians must first become paediatricians
through three years of specialty training. They then spend more years
sub-specialising in the care of sick newborns.
Nubain
Nubain is a potent analgesic. Its
analgesic potency is essentially equivalent to that of morphine on a milligram
basis. Its onset of action occurs within 2 to 3 minutes Its onset of action
occurs within 2 to 3 minutes after intravenous administration, and in less than
15 minutes following subcutaneous or intramuscular injection. The plasma
half-life of nalbuphine is 5 hours and in clinical studies the duration of
analgesic activity has been reported to range from 3 to 6 hours.
The narcotic antagonist activity of Nubain is one-fourth as potent as
nalorphine and 10 times that of pentazocine.
Paediatrician
Specialists in paediatrics
spend at least three years after medical school studying children's health
problems. Many devote additional years to sub-specialise in a particular area of
paediatrics such as heart, lung, or endocrine problems. Paediatricians often
employ nurse practitioners or physician's assistants. These individuals work
under the supervision of the paediatrician and are often an important part of a
paediatric clinic.
Perinatal
Refers to the time period after the
28th week of gestation and ending the first week after birth. Some sources
extend the perinatal period until the fourth week after birth.
Perinatologist
An obstetrician who has
sub-specialised in the care of pregnant women and unborn babies. If you have a
complicated pregnancy or one at high risk of having complications, you may be
referred to one of these physicians. They are often the specialists who perform
the level 2 or detailed ultrasound examination.
Persistent foetal
circulation
The circulation of blood in the foetus is somewhat
different from that of the baby after birth. This transition from foetal to
neonatal circulation is one of the major physiologic changes after delivery.
Before birth, the lungs are collapsed and the blood pressure in the lungs is
quite high. This results in a very low blood flow through the lungs. After
delivery, the lungs expand and the blood pressure in the lungs decreases.
In some babies, although the lungs expand the blood vessels in the lungs
remain constricted resulting in persistently high blood pressure in the lungs.
This reduces the amount of blood that the infant can pump through the lungs.
This decreased blood flow through the lungs after birth is called persistent
foetal circulation because it is a persistence of the pattern of blood flow
normally seen prior to birth during the foetal period.
Infections, malformations of the lung or diaphragm, and lung immaturity can
all cause persistent foetal circulation. This is a very serious, although
infrequent, newborn problem. Several new treatments for persistent foetal
circulation have been developed in the past few years and have increased
survival of infants with this problem. The more medically correct name for
persistent foetal circulation is persistent pulmonary hypertension.
Pitocin®
Synthetic formulation of a hormone,
oxytocin, that stimulates uterine contractions and is
used to induce labour or delivery. Pitocin® is a commonly used drug during
labour.
Placenta
Organ within the uterus that provides
communication between mother and foetus through the umbilical cord. The placenta enables oxygen and
nutrients to pass from the maternal blood to the foetus. It also eliminates
carbon dioxide and waste products from the baby by passing them to the mother,
who excretes them with her liver, kidneys or lungs. It is a disk shaped organ
and at term weighs around 500 grams.
Placenta accreta
Abnormally deep
growth of the placenta into the uterus. Placenta accreta
prevents the normal placental separation from the uterus and often causes severe
uterine bleeding after delivery.
Post partum
Occurring after childbirth,
or delivery.
Postnatal care
Care given to a mother
after she has given birth. Usually this refers to the care given before she is
released from the hospital, but can extend past discharge.
Premature infant
Baby born three or
more weeks before the due date. The length of a pregnancy is measured by gestational age. Gestational age equals the amount
of time that has elapsed since the first day of the last menstrual period. A
normal gestation lasts 40 weeks or 280 days. If delivery occurs before 37 weeks
gestation, the baby is considered prematurely born. About 11% of all babies born
in 1997 (in the USA) were born prematurely by this definition. Irregular
menstrual periods or first trimester vaginal bleeding can confuse gestational
age estimates. To improve the accuracy of gestational age estimates, some
doctors use an ultrasound examination before about 20
weeks gestation. Ultrasound findings help your doctor to confirm or correct the
gestational age estimate.
Premature labour
Onset of labour
before 37 completed weeks of pregnancy. Tocolytic agents (medications used to
inhibit labour) are widely used today to treat premature labour and permit
pregnancy to proceed so that the foetus can gain in size and maturity before
delivery.
Birth weight is lower when a baby is born prematurely. Babies born with a
weight of less than 2500 grams are considered low birth weight babies.
Generally, infants with a birth weight less than 2500 grams are premature;
however, babies can be premature and still weigh more than 2500 grams at birth.
They can also be born at term and weigh less than 2500 grams. There is no
perfect system for categorising infants; both measurements, birth weight and
gestational age, are used.
Many premature deliveries occur close to term and these infants generally do
well. For example, only 1.9 percent of all infants born in 1997 were born at
less than 32 weeks gestation. These infants routinely require lengthy stays in a
special care nursery. These infants are also at risk for long-term problems. The
risk of complications accelerates as gestational age decreases.
Prolapsed cord
Positioning of the umbilical cord ahead of the baby's presenting part
during labour and delivery. When this occurs, the baby's body puts pressure on
the umbilical cord which is caught between the baby and the mother's birth
canal. This pressure can seriously reduce or altogether stop the blood flow
through the umbilical cord.
Unless the pressure is removed through either delivery of the infant or
repositioning of the infant, serious problems occur. Prolapsed umbilical cord
occurs more commonly with breech than with vertex presentation.
Prolonged labour
Labour which takes
an abnormally long length of time. The usual length of time in labour is longer
in primiparous women and varies considerably among individuals.
Prostaglandins
A class of chemicals
produced by the prostate and other parts of the body that can have various and
powerful effects on the body. They were first discovered in the prostate gland, hence their name. Prostaglandins are
sometimes used to induce labour or soften the cervix in anticipation of inducing labour.
Prostate gland
A male reproductive
gland that produces part of the fluid in ejaculate. It surrounds the urethra and
often enlarges in older men to produce urinary symptoms. Prostatic cancer
commonly occurs in older men and is one of the most important cancers in
males.
Rh incompatibility
An
incompatibility of blood types. Blood types are commonly characterised by the
ABO typing system and the Rh system. An incompatibility between the mother and
foetus in either of these systems can result in maternal antibodies crossing the
placenta and destroying foetal red blood cells. The Rh system more often causes
serious problems than the ABO system.
Individuals are either Rh-positive (red blood cells carry the Rh antigen) or
Rh-negative. When a Rh-negative woman is pregnant with a Rh-positive foetus
(Rh-positive inherited from the father), the mother can produce antibodies
against the Rh portion of the foetal red blood cells. These antibodies attack
the foetal red blood cells and destroy them. Loss of the foetal red blood cells
causes elevated bilirubin, decreased red blood cell
count and sometimes even heart failure in the foetus. The combination of these
problems can be fatal.
There are ways to treat this problem before the baby is born. More effective
than treatment is prevention of the problems. Women are exposed to Rh-positive
red blood cells through a previous pregnancy, miscarriage or a mismatched blood
transfusion. If a Rh-negative mother has been exposed to Rh-positive red blood
cells, she should receive Rho-GAM, a special immunoglobulin that destroys the
Rh-positive red blood cells before they can stimulate the woman to produce
antibodies against Rh-positive cells.
Rooming-in
An alternative rooming
arrangement in postpartum units. With rooming-in the infant does not stay in the
newborn nursery, but in the mother's room during her hospital stay.
Small for gestational age
(SGA)
Children whose birth weights are below the 10th percentile
(smaller in weight than 90 percent of other infants born at the same gestational
age) are considered small for gestational age (SGA). Being small for gestational
age has several other names. Some of these follow:
- Intrauterine growth retardation
- Small for dates
- Dysmature
- Light for dates.
SGA has many causes. If your baby is SGA, your baby's doctor should search
for an explanation. This is important because some problems cause reduced growth
in childhood as well. The following is a partial list of factors that can
contribute to an infant being SGA:
- Maternal high blood pressure [mother’s?]
- Cigarette smoking
- Maternal street drug use
- Maternal malnutrition
- Low maternal weight gain (less than 9 Kilograms)
- Mother was also SGA at birth
- Maternal chronic disease (advanced diabetes, anaemia, etc.)
- Frequent, heavy, physical work during pregnancy
- Mother younger than 20 years of age
- Racial and ethnic background
- Multiple foetuses (twins, triplets)
- Rubella, cytomegalovirus, and other infections during pregnancy
- Placental abruption (separation of the placenta from the uterine wall)
Foetal chromosome problems (Children with abnormal chromosomes seem
genetically programmed to remain small and not gain weight appropriately.)
SGA babies have more problems in the newborn period than infants who are
appropriately grown. Examples of these problems are low blood sugar and too many
red blood cells in the blood. These problems are all treatable, but may require
NICU care. SGA babies are also more likely than AGA (appropriate for gestational
age) infants to be small throughout life and have delayed development. Babies
whose growth slowed down later in pregnancy are more likely to catch up with
their peers than those whose growth was slow throughout pregnancy.
Stadol
Stadol NS is the trade
name for butorphanol tartrate nasal spray. Stadol NS is a special type of
prescription pain reliever used to treat moderate to severe acute pain,
including the pain of a migraine attack in progress. Although it is a potent
analgesic, it does not incorporate the addictive properties of many narcotic
drugs. Stadol NS was designed to activate certain receptors in the brain to
eliminate pain while blocking the receptors that cause euphoria. In other words,
it is designed to stop the pain without causing a 'high'.
Ultrasound
Imaging of body parts using sound
waves. Ultrasound uses sound waves that are above the range of human hearing to
create an image of organs within the body. Sound waves are reflected off
internal body structures and back to the ultrasound machine. The reflected sound
waves are analysed by computer and turned into pictures. This method of imaging
results in less clear pictures than X-rays, CAT scans or MRI. However, there is
no radiation risk with ultrasound and no confirmed adverse effects on the foetus
or mother from diagnostic ultrasound examinations in pregnancy.
There are different types of ultrasound exams. They are differentiated by the
purpose for which they are done and the level of detail obtained.
- Limited exams are focused studies used to answer specific questions about
the foetus, mother, or both. This exam is often used when you go to your doctor
or the hospital with an urgent problem related to your pregnancy.
- Basic exams are performed to survey for obvious malformations of the foetus
and to estimate foetal age, the amount of amniotic
fluid present, location of the placenta, and for
other concerns. These are the kind of exams that you would likely receive in
your doctor's office or in the hospital as a routine evaluation. They are
typically performed at 18-20 weeks of pregnancy.
- Comprehensive exams are a more in-depth look at the foetus when there is
reason to suspect something is wrong with the foetus or mother. They include a
detailed examination that is often done as a response to an abnormal screening
test such as the alpha-fetoprotein
screen. In some areas of the country this is called a Level II or Level III
ultrasound. Technical difficulties and the need to image many different areas of
the foetus may extend the length of this exam to 30 or more minutes.
Ultrasound can measure foetal size, the amount of amniotic fluid, estimate foetal gestational age, identify multiple foetuses, some
foetal abnormalities such as microcephaly or Down
Syndrome, and locate the location of the placenta.
Although an ultrasound can usually determine gender of your baby, many families
do not want to know this information before delivery and some ultrasound centres
have a policy of not revealing the gender.
Umbilical cord
The baby's lifeline
from the mother during pregnancy. The umbilical cord is formed during the fifth
week of gestation and connects the foetus' circulation with the mother's placenta. Through this vascular structure, the foetus
receives nutrients such as oxygen, glucose, and protein. When the baby is born
the cord is about 600 mm long and 12 mm thick.
The umbilical cord is clamped and cut shortly after birth. It will turn black
within the first few days and should protrude about 25 mm or less. It will fall
off within about 2-3 weeks. It is important to care for the umbilical stump to
ensure proper healing. Fold nappies below the stump to expose it to air and keep
it dry. Cleaning should be with a cotton swab and alcohol. The ideal time to do
this is just after changing a diaper. If you notice that the skin around the
stump has turned red or if the cord is oozing, call your doctor.
Umbilical hernia
Hernia at the belly
button. (see hernia.) The abdominal wall is formed by two
sheets of muscle that run along both sides of the abdomen. In normal
development, these sheets of muscle fuse together. When the fusion is incomplete
or abnormal, part of the bowel can bulge through the space between the muscles
at the belly button. As the infant grows, the muscle layers increase and
gradually fuse, eliminating the hernia. This is one of the few hernias that
often resolves on its own. Occasionally, surgical correction is required.
Uterus
Also called the womb. The uterus is the
organ that houses and protects the foetus during pregnancy. The uterus grows and
expands with your baby's growth. Your doctor will measure this growth during
prenatal visits. The uterus also helps the foetus leave the womb through
contractions. It will take several weeks to months after delivery for your
uterus to regain a normal shape and size following delivery.
Vacuum extraction
The application
of a suction cup to the head for helping deliver the infant. This technique
performs a similar function as forceps and helps
the baby to descend through the birth canal. The vacuum extractor has a soft
plastic cup attached to a tube and suction pump. The cup is inserted into the
birth canal and attached to the baby's head by suction. Increasing the suction
causes a vacuum and the handle of the cup can be used to pull the baby out of
the birth canal. The vacuum extractor is more gentle and less damaging to the
mother's soft tissue than forceps. However, there are risks with the vacuum
extraction. Excessive suction or traction can cause injury to the mother or
baby. There is also a limit on the number of pulls that should be made with the
suction device attached.
Vaginal birth
Delivery of the infant
through the birth canal, of which the vagina is a major component. The
alternative method would be an operative delivery (caesarean section).
Vaginal birth after
caesarean (VBAC)
A vaginal delivery after a previous caesarean delivery. One of the most common reasons
for caesarean sections is the presence of a uterine scar from a previous
caesarean section. A previous uterine scar can tear or open up during a hard
labour with a subsequent pregnancy. For many years it was thought that once a
caesarean, always a caesarean. This is not so. If the incision from the previous
caesarean section has been performed low on the uterus, the scar is often
sufficiently strong to withstand labour.
The advantages of a VBAC are decreased risk of surgical complications and a
shorter recovery period. However, a VBAC is not possible for everyone. The type
of incision previously made is one important determinant. For example, if you
had a classical incision through the uterus, which is high up on the uterus, an
attempted vaginal birth would not be a good idea because there is a risk of
uterine rupture during labour. Multiple foetuses, medical complications such as
high blood pressure or abnormal foetal position may all require a caesarean
section and prevent a VBAC trial. If a VBAC is attempted you will need foetal
monitoring and IV in case a section becomes necessary. The risk of uterine
rupture is low, but if it occurs, the consequences can be severe for both the
mother and the baby.
Ventilator
A machine that assists adults or
children to breathe. This most often refers to newborn infants who sometimes
have breathing problems so severe that they need help from a breathing machine.
If your baby was born with lung problems or didn't breathe on his own he may be
connected to a ventilator. Lung immaturity in prematurely born infants is the
most common reason for a newborn to require a ventilator.
Vernix
Also called vernix caseosa. A cheesy,
white substance that covers a baby's skin at birth. The vernix is secreted by
the sebaceous glands around the 20th week to protect the baby's skin from the amniotic fluid. Without the vernix, the baby would
have very wrinkled skin from constant exposure to the watery amniotic fluid. The
amount of vernix present decreases toward the end of gestation. Remaining vernix
is washed off after birth. The loss of vernix may cause the skin to peel during
the first postnatal week.
Vertex
A vertex presentation is the most common
and desirable. In this position the baby's head enters the birth canal
first.
Very low birth weight
(VLBW)
A birth weight of less than 1500 grams. Babies with such a low
birth weight are almost always very prematurely
born. About 1.3% of all births result in babies with a birth weight of less
than 1500 grams.
Viable
Able to survive. Refers to the condition
of a newborn.
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