Childbirth is one of nature's
greatest wonders. We live in an age where we expect a perfect outcome but throughout history until just a couple of generations ago, childbirth was a most precarious event. Mercifully mortality has been reduced to just 2% compared to a century ago and we can now concentrate more on the outcome for the baby.
We are increasingly turning to the internet for information. Questions about health are amongst the more common reasons for Web searches.
Patients rightly wish to be involved in decisions about their care. There are often options
relating to investigations and management. The purpose of this Web site is to present the background for decision making and to explore areas of current debate.
For those
without medical training, all medical terms in the text have a link to the
explanation.
'Obstetric Health .com' is for discerning
people who wish to appreciate the background to pregnancy related treatment
options. Health professionals, including nurses, medical students, junior
doctors and general practitioners looking for a text that provides a
balanced discussion of the issues, rather than a basic review of the
essential clinical facts, may find this book helpful not only for obstetrics
and midwifery but as a framework for the caring aspects in the art of
medicine. Those
studying for postgraduate qualifications, may find the presentation, with
links to clinically relevant medical abstracts, to be of assistance.
Links to
the abstracts of selected medical papers are provided to allow a more
in depth understanding. This area of the Web site will be an ongoing
project. The ethos of this e-book is to explain the advantages and
disadvantages of the various options whilst leaving it to each individual to
come to their preference according to their particular circumstance.
During pregnancy one (or more) offspring, known as an embryo
(early pregnancy) or fetus (from about 8 weeks into the pregnancy), develop
inside the uterus of a woman.
Pregnancy occurs as the result of the female gamete or oocyte (egg)
being penetrated by the male gamete
spermatozoon in a process referred to, in medicine, as "fertilization",
or more commonly as "conception". The fusion of male and female
gametes usually occurs through the act of
sexual intercourse. However, the advent of
artificial insemination and in vitro fertilization (IVF) has also made achieving
pregnancy possible in
such cases where sexual intercourse is not potentially fertile (through
choice or male/female infertility). In
the majority of human pregnancies, only one baby develops (singleton
pregnancy) but there can be more (multiple
pregnancy) as in the case of twins or
triplets. Some infertility treatments, particularly IVF, are prone
to result in multiple pregnancy. The outer layers of the embryo grow and
form a
placenta,
for the purpose of receiving oxygen and essential
nutrients and removing carbon dioxide and waste products. The
umbilical cord in a newborn child consists of the remnants of the
connection to the placenta. The developing embryo undergoes tremendous
growth and changes during the process of
foetal development.
Obstetrics and the
Pregnant Woman
Obstetrics is the medical field that studies and treats pregnant women and the doctors who specialise in obstetric medicine are known as
obstetricians.
Childbirth usually occurs about 38 weeks from
fertilization, i.e., approximately 40 weeks from the start of the last
menstruation.
A commonly used scientific term for the state of being pregnant is
gravid, and a pregnant
woman is sometimes referred to as a
gravida.
Similarly, the term "parity"
(abbreviated as "para") is used for the number of previous deliveries
occurring after 24 weeks. Women who have never been pregnant before are
referred to as "nulliparous" and during a first
pregnancy as a "primigravida" ("gravida 1, para 0") and in subsequent
pregnancies as "multigravida" or "multiparous".
Hence during a second pregnancy a woman would be described as "gravida 2,
para 1".
Pregnancy is divided into three
trimester periods. The first trimester of pregnancy concludes at 16
weeks and carries the highest risk of
miscarriage. In
some cases the fertilized egg might implant itself in a
fallopian tube, causing an
ectopic pregnancy. The second trimester of pregnancy tends to be less prone to
complications. Most women feel more energized in this period, and begin
to put on weight as the symptoms of morning sickness subside and eventually
fade away. Although the
fetus begins
moving and takes a recognizable human shape during the first trimester, it
is not until the second trimester that movement of the fetus, often referred
to as "quickening",
can be felt. This typically happens by the fourth month. The placenta is now
fully functioning The third trimester of pregnancy commences at 28 weeks
and approximates the point of
viability, or the ability of the fetus to survive, with or without
medical help, outside of the
uterus.
The use of modern medical
intensive care technology has greatly increased the probability of
premature babies living, and has pushed back the boundary of viability to
much earlier dates than would be possible without assistance.0801
These advances in the quality of neonatal care have resulted in survival of many babies delivered
at 24 weeks and even earlier. An unfortunate complication of extreme prematurity is morbidity.
Calculating Dates In Pregnancy
Most pregnant women do not have any specific signs or symptoms of
implantation, although it is not uncommon to experience light bleeding at implantation. Though
pregnancy begins at implantation, it is more convenient to date
from the first day of a woman's last menstrual period (LMP). Starting from
one of these dates, the expected date of delivery (EDD) can be calculated. Counting
from the LMP, pregnancy usually lasts between 37 and 42 weeks, with the EDD
at 40 weeks,
or
38 weeks following conception. 40 weeks is nine months and
six days, which forms the basis of
Naegele's rule for estimating date of delivery. Less than 10% of births occur
spontaneously on the EDD; 50%
of births are within a week of the due date, and almost 90% within two
weeks.
Dating a pregnancy is only a rough estimate, and the process of accurately dating a
pregnancy using the LMP method is complicated by the fact that not all women have 28 day
menstrual cycles, nor ovulate on the 14th day following their last menstrual
period. Unless a woman's recent
sexual activity has been limited, or she has been charting her cycles,
or the conception is as the result of some types of fertility treatment
(such as
IUI or
IVF) the exact date of fertilization is unknown.
Pregnancy is considered 'at term' when gestation attains 37 complete
weeks but is less than 42. Events
before completion of 37 weeks (259 days) are considered
pre-term; from week 42 (294 days) events are considered to be
post-term.
When a pregnancy exceeds 42 weeks (294 days), the risk of complications for
mother and fetus increases significantly. This is one indication for
obstetricians to recommend induction of labour, generally between 41 and 42 weeks.( Induction
of Labour) Obstetricians have tended to refer increasingly to pre-term and
post-term rather than premature and post-mature.
Accurate dating of pregnancy is important for several reasons. It is used in
determining the significance of results of various
prenatal tests such as the
triple test - a screening test for
Down syndrome. Assessment of the
appropriateness of the fetal size depends on an accurate knowledge of the
gestational age. Interventions may be indicated if the fetus is small or
large for dates. A decision may be made to delay delivery if labour begins
prematurely and to administer steroids to reduce complications or to
induce labour (Induction
of Labour) if a fetus is believed to be overdue.
A number of
symptoms and
signs are associated with pregnancy:-
If you have
normal regular cycles then a missed
period is more than likely can
indicate a pregnancy. On occasion
or it may be related to an illness
or stress. It is considered one of
the major possible symptoms of
pregnancy.
Unusual or
abnormal period
A period or
menstrual cycle that is different in
some way. The period may be last
longer or shorter. It may be a
difference in the amount of flow.
Any of these variances may indicate
that you are pregnant.
Just "feeling" pregnant
Many women
just know when they are pregnant.
Nausea and
Vomiting
If you were
to ask women to name a single
pregnancy symptom, morning sickness
would be at the top of everyone's
list.
Increased
urinary voiding
The urgent need to empty the
bladder, even small amounts,
throughout the day and night is
caused by pressure of the enlarging
uterus on the bladder. It is helpful
not to drink too much just before
going to bed. No treatment is needed
for urinary frequency alone but if
micturition becomes painful, urinary
infection should be excluded.
Food
aversions or cravings
When you're pregnant, you might find yourself turning up your
nose at certain foods, such as
coffee or fried foods. Food cravings
are common, too. Like most other
symptoms of pregnancy, these food
preferences can be chalked up to
hormonal changes ? especially in the
first trimester, when hormone
changes are the most dramatic.
Heartburn and
Constipation
The smooth
muscle of the stomach and bowel
relax more in pregnancy in response
to progesterone, the pregnancy
hormone. You may require antacids
for the heartburn. Ensure adequate
fluid intake to reduce constipation.
Mild laxatives may occasionally be
required.
Positive
Pregnancy Test
Modern
pregnancy tests are extremely
accurate, often being positive even
before a missed period.
Ultrasound
Ultrasound
may be able to show the pregnancy
from about 5 weeks.
Fetal Heart
Tones
With modern
sonicaid monitors, the baby's heart
beat can be heard from about 14
weeks.
Tender Breasts
Early in the first trimester you may notice that your breasts are sore or tender. For some women this is also a sign of an impending period, so it may go unnoticed. You may have a slight tenderness when you touch your breasts or you can have the severe pain whenever you wear a bra. Both variants are normal and are usually most intense in the first trimester. This is one of the reasons that sex in the first trimester is often avoided by some women. Sex in
pregnancy is safe, you may just want to avoid having anyone touch your nipples.
Enlargement of
the Breasts
Towards the
end of the first trimester or the
beginning of the second trimester
you may notice that your breasts
begin to grow. This is again the
tissues inside the breast preparing
for nursing. Towards the end of
pregnancy you will want to be fitted
for a nursing bra to help
accommodate the larger breasts.
Nipple Colour
Changes
Your nipples and the area around the
nipples (areola) get darker and
broader.
Montgomery's
Tubercules
These are
small goose bump like raised areas
on the areola of your breast.
Colostrum from
the breasts
Colostrum
is a pre-milk substance that is high
in antibodies and works to get the
meconium out of your baby's system
after birth. It can appear at any
point during pregnancy, but is not
seen in all women.
Changes in
libido
You and
your partner may find your desire
for sex increased because you do not
have to think about birth control.
The vagina is more lubricated and
the clitoris and vagina are more
engorged. Many women will become
orgasmic or multi-orgasmic for the
first time during pregnancy because
of this added engorgement.
Strange
Cravings
Some
studies show that up to 68% of women
will have a craving at some point
during pregnancy.
Fatigue
This is
nature's way of making you take some
extra rest which is probably healthy
in pregnancy.
Skin Changes
Striae
gravidarum, or stretch marks, are
probably the most discussed of the
skin changes during pregnancy. They
appear in 50 - 90 of all pregnant
women, usually showing up in the
later half of pregnancy. While the
majority will be on the lower
abdomen they can also be found on
the thighs, hips, buttocks, breasts
and arms of women. They reflect the
separation of collagen of the skin.
While not painful the stretching of
the skin may cause a tingling or
itchy sensation.
These are most
commonly seen as small depressions
in the skin. They tend to be pinkish
in light skinned women, and in dark
skinned women they will be lighter
than the surrounding skin.
While
many people will swear by certain
creams or lotions, the truth is
there's there is no evidence that
any of them are effective. Striae
gravidarum are exacerbated if you
gain weight excessively and so you
may help yourself by taking care of
your diet.
Quickening
(Fetal Movement)
This is the time that you feel your
baby move for the first time. Fetal
movement begins around eighteen
weeks into the pregnancy.
Enlarged
abdomen
As the baby
grows the pregnancy begins to
'show'.
Braxton Hicks
Contractions
The uterus
is a muscular organ and
contractions occur throughout
pregnancy. As term approaches, they
become stronger. This is normal.
Fetus palpable
From about
28 weeks you may be able to feel the
parts of the baby particularly the
head.
X rays
With the
advent of ultrasound, x-rays are
rarely used nowadays in pregnancy.
Emotional
Changes
Most women experience emotional mood
swings. It's natural to feel doubt,
anxiety, and fear about pregnancy
and childbirth, as well as
happiness, excitement, and
anticipation.
Weight gain
The average
weight gain is 25lb with about 1
pound per week in later weeks.
Fainting
This
is more common in late pregnancy,
particularly if the pregnant woman
lies flat on her back and the
pressure of the pregnant uterus
reduces the blood flow in the big
vessels returning blood to the
heart. Fainting may occur in early
pregnancy and is usually related to
sudden change of position, such as
when sitting up from recumbency, or
standing up from the sitting
position. If you feel faint, lie
down with your feet elevated and
your head flat. Avoid standing for
long periods and don't rush around.
Be particularly careful getting up.
Although not all of these signs are universally present, nor are
all of them diagnostic by themselves, taken together they make a presumptive
diagnosis
of pregnancy. These signs include the presence of
human chorionic gonadotropin (hCG) in the blood and
urine, missed
menstrual period, implantation bleeding that occurs at
implantation of the embryo in the uterus during the third or fourth week
after last menstrual period, increased
basal body temperature sustained for over two weeks after ovulation,
Chadwick's sign (darkening of the
cervix,
vagina, and
vulva),
Goodell's sign (softening of the vaginal portion of the cervix),
Hegar's sign (softening of the
Vaginal fornix), and
Linea
nigra, (darkening of the skin in a vertical line on the abdomen, caused
by
hyperpigmentation resulting from hormonal changes; it usually appears
around the middle of pregnancy).
The beginning of pregnancy may be detected in a number of ways, including
various pregnancy tests which detect hormones generated by the newly-formed
placenta
(afterbirth).
Clinical blood and urine tests can detect pregnancy within a few days of
implantation, which is as early as 6-8 days after fertilization.
Following the development of the
blastocyst (early embryo) a hormone named
human chorionic gonadotropin (HCG) is produced and this stimulates the
corpus luteum in the woman's ovary to produce
progesterone (hormone in favour of pregnancy). This maintains the lining
of the uterus so that the embryo will continue to be nourished.
An early
ultrasound
examination can accurately determine gestational age. This method is slightly more accurate
than methods based on LMP.9901
During the first three months of
pregnancy, feeling sick or nauseated is quite common, as is vomiting.
Morning sickness can occur in about seventy percent of all pregnant
women and typically improves after the first trimester. Most
miscarriages occur during this period. The
problem varies from woman to woman. Some just feel a little sick in the
morning and throw up once, whilst others suffer from constant nausea and
frequent vomiting throughout the day. About 75% of women are troubled and
the incidence has not changed over 20 years.0301,
0601
For the majority, the nausea stops after the first three months of
pregnancy. A few, however, continue to have problems even after four or five
months.
Causation
The actual causes of nausea and vomiting
are still unknown. It is probably brought about by the hormonal changes.
Physiological, psychological, genetic, and cultural components have been
quoted as contributing factors0101
although evidence that underlying depression is a risk factor is lacking.0602
It is not increased in association with malformed babies. Younger women are
more troubled by it. It is increased when there have been a number of
miscarriages. Twin pregnancies are more affected.0601It is not increased in association with malformed babies. It is
increased when there have been a number of miscarriages.0601
There is a some good news. Morning sickness is
associated with pregnancies that are less likely to result in miscarriage,
preterm delivery, or intrauterine growth retardation.0101
There is no evidence that morning sickness, even if severe, causes any harm
to your baby. It has been suggested
that morning sickness is promoted by secretion of human chorionic
gonadotrophin (hCG), largely on the basis of the coincidence between the
onset of NVP and hCG secretion and the peaks of both at around 12 to 14
weeks' gestation and also the increase in symptoms associated with twins.
Furthermore, when there is a
hydatidiform mole, hCG and morning sickness are both
increased.
Risks
of Morning Sickness
If you are vomiting heavily and often, you
may lose so much liquid that it causes dehydration. When morning sickness is
this severe it is called hyperemesis gravidarum and requires medical
attention. This usually requires hospital admission and being given fluids
through an intravenous drip.
Reducing Morning Sickness
Problems
Treatment generally begins with non-pharmacologic interventions; if symptoms
do not improve, drug therapy is added.
In the mornings:-.
Do not rush about.
Take your time getting out of bed.
If you tend to feel really sick in the
morning, eat a little as soon as you wake up and before getting out
of bed.
Ask your partner to bring the food to you,
or prepare a snack the night before and leave it beside your bed.
Throughout the day:-
Eat little and often, every two or three
hours - even if you're not hungry.
Open windows or turn on exhaust fans when
cooking and after meals.
Cooking in the microwave usually produces less
odours.
Drink a lot of liquid, preferably 10 to 12
glasses of water, fruit juice or herbal tea each day.
Avoid food containing a lot of fat or
spices.
Avoid alcohol and caffeine.
Eat dry crackers, toasted bread or rusks.
Ginger tea or ginger tablets can help
reduce nausea.0501,
0502
Rest several times a day. Lie down with a
pillow under your head and legs.
Move slowly and avoid sudden movements.
After eating, sit down so that gravity
helps to keep the food in your stomach.
Avoid smells that make you feel sick or
throw up.
Get some fresh air and exercise by going
for a little walk every day.
Avoid smoking. Not only is it harmful for
you and your child, it also diminishes your appetite.
At night:-
Before going to bed, it may help to eat a
snack such as a yoghurt, bread, milk, cereal or a sandwich.
If you wake up during the night, eating a
small snack may stop you feeling sick in the morning.
Sleep with the windows open to get some
fresh air, if possible.
Visit your doctor
If none of the remedies mentioned above seem
to work.
If you vomit more than three or four times a
day.
If you lose weight.
If your vomit contains blood or looks like
ground coffee.
If you lose more liquid than you can keep
down.
If you are worried about your condition, or
believe that something serious is the matter.
Your doctor may examine you for signs of
dehydration. A simple
urine test (ketones) is often helpful in deciding the degree of
dehydration.
Anti-sickness tablets, notably antihistamines and pyridoxene (vitamin B6) can be prescribed.
There is evidence for their effectiveness and safety of these medications.0301
Your doctor will be careful to
ensure you are prescribed medication that does not harm your baby.
Acupressure was found to be effective in reducing symptoms
of nausea but not frequency of vomiting in pregnant women 9401 but a
more recent study0701
found that
acupressure therapy is no more effective than vitamin B6 in reducing nausea and vomiting in symptomatic women in the first trimester of
pregnancy.
Prenatal medical care is of recognized value throughout the developed
world. Periconceptional Folic
acid supplementation is the only type of supplementation of proven
efficacy.
A balanced, nutritious diet is essential for a healthy
pregnancy. Balancing
carbohydrates,
fat, and
proteins, and eating a variety of
fruits and
vegetables usually ensure good nutrition. Those whose diets are affected
by health issues, religious requirements, or ethical beliefs may choose to
consult a health professional for specific advice.
Adequate periconceptional folic
acid intake has been proven to limit fetal neural tube defects including
spina bifida.
Folates (folia, leaf) are abundant in
spinach
(fresh, frozen or canned), and are also found in
green vegetables, salads, melon,
eggs and hummus.
In Canada and the United States, most wheat products are fortified with folic acid.
There is some evidence that
omega-3 (n-3) fatty acids have a beneficial effect on the developing fetus, but
further research is required.0701
At this time, supplementing the diet with foods rich in these fatty acids is
not recommended, although it seems to be safe.0702Potenteially dangerous bacteria or parasites may contaminate foods, particularly listeria
(soft cheeses may contain listeria, if milk is raw)
and toxoplasma. Cat faeces pose a particular risk of toxoplasmosis. Practicing good hygiene in the kitchen can reduce these risks.
Caloric intake must be increased, to allow for the development of the
fetus. The amount of weight gained during pregnancy varies.
The
recommendation is that overall weight gain during the 9
month period for women who start pregnancy with normal weight be 10 to 12
kilograms.
Excessive weight gain can pose risks to the woman and the fetus. Women who
are prone to being
overweight may choose to plan a healthy diet and exercise plan to help
moderate the amount of weight gained.
Most pregnant women can enjoy
sexual intercourse throughout pregnancy. Most research suggests that,
during pregnancy, both sexual desire and frequency of sexual relations
decrease.0201
In context of this overall decrease in desire, some studies indicate a
second-trimester increase, preceding a decrease. However, these decreases are not universal: a significant number of women
report greater sexual satisfaction throughout their pregnancies.
Until the mid 20th century, it was considered a
socio-moral "taboo" action for pregnant women to engage in sexual activities. This is far from universal however, for
example the
Talmud recommends it for the health of the mother and child.
Sex during pregnancy is a low-risk behaviour except when the physician advises that
sexual intercourse be avoided, which may, in some pregnancies, lead to
serious pregnancy complications or health issues such as a high-risk for
premature labour or bleeding if the placenta is planted low in the uterus
(placenta praevia).
We
calculate your due date by simply adding 280 days to the day when you
started your monthly cycle. The human gestation period is actually 266 days,
so by adding 14 days, which is the average ovulation period to the first day
of your cycle, we come to the 280 day figure. Of course, if you have been
monitoring your cycle and know when you ovulated, it does make it easier to
calculate your conception and due dates.
Within this trimester the
most rapid rate of growth and development take place. All the organs have
developed. Of course the majority of early pregnancies fare well but
complications including
miscarriage and
ectopic pregnancy can occur.
Pregnancy symptoms,
such as
morning sickness, and
pregnancy signs such
as an enlarging uterus, occur. By the end of the 1st trimester, your
son or daughter will have grown to 3.4 inches (8.7 cm) long and weigh about
1.5 ounces (43 grams).
The majority
of babies are healthy but abnormalities such as Down's Syndrome can occur
and you will need to consider your options with regard to
antenatal screening.
Pregnancy Week
by Week - Weeks 1 - 4
Ovulation occurs 14 days before your next period is due.
The gender
of your baby is determined at the time of fertilization. A spermatozoon
carries either an "X" (girl) chromosome or a "Y" (boy) chromosome.
Implantation occurs a few days after conception.
The neural
tube forms - it will develop into the nervous system - brain and spinal
cord.
The heart
and primitive circulatory system rapidly form.
Picture -
Four cell embryo
Four week embryo
Pregnancy Week
by Week - Week 5
The first
heartbeats begin - If you have an early ultrasound you may not be able
to recognize this tiny being as a baby, but there is no mistaking what
it feels like seeing your baby's heartbeat on that screen.
The umbilical cord develops - this is your baby's lifeline in utero. It
carries in oxygen, and takes away waste, and supplyies the necessary nutrients for the remainder of your
pregnancy.
Blood
is now pumping - All four heart chambers are now functioning, insuring
your baby's body will receive all it needs over not only the remainder
of your pregnancy but throughout life.
Most
other organs begin to develop - the lungs start to appear,
along the brain.
Arm and
leg buds appear.
Pregnancy Week
by Week - Week 6
Picture of a mother and
her baby
The
arms and legs continue to develop.
The brain
is growing well - over the course of the remaining months that your
baby's brain will develop over 100 billion neurons?
The
lenses of the eyes appear.
The nostrils are formed. Soon, the nerves running from the nose to the
brain develop.
The intestines grow - initially these are actually located outside the
baby's body.
The length of the baby is measured from the crown to the rump (bottom)
as the legs are flexed.
Pregnancy Week
by Week - Week 7
The
elbows form.
The
fingers start to develop.
Feet
start to appear with tiny notches for the toes.
The ears,
eyes and nose start to appear.
Teeth
begin to develop under the gums.
Pregnancy Week
by Week - Week 8
Cartilage and bones begin to form.
The
basic structure of the eye is underway.
The
tongue begins to develop
The intestines start to move into the abdomen.
The
fingers and toes have appeared but are webbed and short.
Baby's
length (crown to rump) is 0.61 inch (1.6cm) and weight is 0.04 ounce
(1gm)
Pregnancy Week
by Week - Week 9
Baby
has begun movement.
Most
joints are formed.
Fingerprints are already evident in the skin
Photograph of a happy couple
Pregnancy Week
by Week - Week 10
The
baby is now called a fetus in "medical terms".
The
most critical part of your infant's development is complete. Now you are
headed into a period of rapid growth.
While a
bit strange to envision, your baby's head is now about half its length.
Eyelids
fuse shut and irises begin to develop - eye colour is also determined by
this point.
Pregnancy Week
by Week - Week 11
Nearly
all structures and organs are formed and beginning to function.
Fingers
and toes have separated.
Hair
and nails begin to grow
The
genitals begin to take on the proper gender characteristics.
Amniotic fluid begins to accumulate as the kidneys begin to function -
this fluid, consisting primarily of water, helps provide a cushion for
your baby whilest nestled within your womb.
The
muscles in the intestinal walls begin contractions that
will eventually allow digestion of food.
Pregnancy Week
by Week - Week 12
The
vocal cords begin to form.
The
eyes begin to move closer together.
The ears
shift to their normal place on the side of the head
The liver begins to function.
It has responsibilities for cleansing the blood, storing nutrients, and
providing needed chemicals.
The
pancreas begins to produce insulin
Your baby's average size is now at a whopping length: 2.13 inches
(5.4cm) and weight: 0.49 ounce (14gm)
Pregnancy Week
by Week - Week 13
Baby begins to practice
inhaling and exhaling movements.
Baby's
neck is getting longer, and the chin no longer is resting on his chest
The
hands are becoming more functional.
On your
next doctor visit you may be able to hear heartbeat with a Doppler by
now.
Picture of a mother with her twin babies
Pregnancy Week
by Week - Week 14
The thyroid
gland begins to produce hormones that will be
used throughout life to adjust the speed of the body's chemistry.
In
boys, the prostate gland develops
In
girls, the ovaries move from the abdomen to the pelvis
Your
baby's skin is very transparent still.
Lanugo
(very fine hair) covers the baby's body and will continue to grow until
26 weeks gestational age - Generally this will be shed prior to birth.
Its purpose is to help protect baby's skin while in all that water!
Pregnancy Week
by Week - Week 15
Occasionally mothers report that they begin to feel some fluttering
movements as baby kicks, flails, twists and turns.
Your
baby's legs have grown longer than the arms and the body is now longer
than the head.
The
three tiny bones in his middle ear have begun to harden. The auditory
centres in your baby's brain haven't developed yet,.
Eyebrows are beginning to grow and scalp hair begins to show. It will probably change colour and texture after birth.
Pregnancy Week by Week - Week 16
Fat
begins to form underneath skin, providing your baby with insulation for
the coming months.
Baby and placenta are now about the same size?
The genitalia are developed sufficiently that an
experienced ultrasonographer might be able to determine if your baby is a boy
or a girl.
The
heart is pumping as much as 6 gallons of blood a day and beats at a rate
about double your heart rate.
Your
baby has learned to breathe.
The Second Trimester -
Weeks 16-28
For many
women, the second trimester is an enjoyable time --
morning sickness has receded and the aches and pain of advanced
pregnancy are far in the future. Your body is finally expanding enough for
people to realize you're pregnant and not just gaining a few pounds.
By the end of this trimester your baby is between 11 and 14 inches long and
weighs about 2 to 2? pounds and swallowing and hearing have developed. You
will notice periods of activity. Check below to see what's happening with
your baby week by week!
Photograph of a pregnant woman in an antenatal clinic
Pregnancy Week
by Week - Week 17
He or
she has a much more normal "human" appearance now.
Pads
are forming on his tiny fingertips and toes. Soon those individual
swirls and whorls will be apparent.
Meconium (composed of products of cell loss, digestive secretion and
swallowed amniotic fluid), is accumulating in the bowel. This black
gooey substance will become your baby's first motion.
The
skeleton is transforming from cartilage to bone. The head bones remain
flexible to make the journey through the birth canal easier.
Pregnancy Week
by Week - Week 18
Vernix, a white protective material, forms on baby's skin,
and together with the
lanugo, serve to protect your baby's skin during the months in water.
Tiny
air sacs called alveoli begin to form in lungs.
Features of your baby's heart, including ventricles and chambers, should
be visible during an ultrasound.
Pregnancy Week
by Week - Week 19
Throughout baby's body, nerves are being coated with a fatty substance
called myelin, which insulates the nerves so that impulses can flow
smoothly.
Scalp
hair becomes apparent this week.
The
milk teeth buds have already developed and over the next few days the
buds for the permanent teeth will begin to form behind the milk teeth.
If baby
is female the uterus starts to develop. If you're having a girl, the
vagina, uterus, and fallopian tubes are in place.
If it's
a boy, the genitals are distinct and recognizable.
Your
baby is swallowing amniotic fluid and his or her kidneys are making
urine.
Pregnancy Week
by Week - Week 20
The
rapid growth stage is about over.
The
legs are reaching their relative size. With the increase muscle develop
occurring as well, you will start feeling much more than tiny flutter
kicks soon!
Antibodies are being transferred from you to your baby now. They will protect
your child.
The
nerve cells for taste, smell, hearing, seeing, and touch are now
developing in specialized areas of the brain. Production slows down as
existing nerve cells grow larger and make more complex connections.
Your
baby may startle in reaction to loud sounds.
Baby is
about 6.46 inches (16.4cm) and weighs around 10.58 ounces (300g).
Pregnancy Week
by Week - Week 21
Leukocytes,
the white blood cells, are under production. The form
our body's defence systems, helping to fight infections and diseases.
Your
little one's skin becomes more opaque.
The
tongue is fully formed.
Unlike
males, females have a limited supply of gametes in their lifetime. At this point your
daughter will have 6 million eggs. This amount decreases to
approximately one million by birth.
Baby
swallows more this week. After your baby takes in amniotic fluid, his
body absorbs the water in the liquid and moves the rest into the large
bowel. This is good practice for the digestive system.
Wake
and sleep periods become more consistent.
Length
is now measured crown to heel.
Pregnancy Week
by Week - Week 22
Eyelids
and eyebrows are fully formed.
Fingernails have grown to the end of the fingers.
If your
baby is male his testes begin their descent to the scrotum.
Primitive sperm have formed and he is producing testosterone.
Pregnancy Week
by Week - Week 23
The proportions of the body are now quite similar to a newborn although
thinner since he hasn't begun to form body fat.
The
bones of the middle ear harden.
The
eyes are formed, though the iris still lacks pigmentation.
The
pancreas, essential in the production of hormones, is developing
steadily with production of insulin, important for the breakdown
of sugars.
If born now, your baby has a 15% chance of survival,
his odds going up with each passing day.
Pregnancy Week
by Week - Week 24
Taste
buds begin to form.
Little
creases have appeared on the palms.
Over
the next seven days the sweat glands will be forming in the skin.
Cells
start developing in the lungs that
will produce surfactant, a substance that helps the air sacs inflate easily. Without
surfactant the fetal lungs would stick together and couldn't expand
after the baby is born.
This
week your baby is officially considered viable.
Baby
weighs 1.3 pound (600gm) and is 11.8 inches (30cm) long -- almost the
length of a ruler!
Pregnancy Week
by Week - Week 25
Your
baby's nostrils begin to open.
The
nerves around the mouth and lip area show more sensitivity. When baby is
rooting for food later on, these will be valuable.
Swallowing reflexes are developing.
Pregnancy Week
by Week - Week 26
To
support the fetus's growing body, the spine is getting stronger and more
supple.
Although they've been sealed shut for the last few months, your baby's
eyes are opening and beginning to blink this week. Depending on
ethnicity, some babies will be born with blue or gray-blue eyes, which
may change colour in the first 6 months of life and some will be born
with brown or dark eyes.
Retinas
begin to form.
Pregnancy Week
by Week - Week 27
Response to sound grows more consistent toward the end of the seventh
month, when the network of nerves to the ear is complete.
Lungs
continue to grow and prepare for functioning outside of the womb. Each
day in the womb greatly increases survival rates.
Eyelids
are now open more.
Retinas
have formed.
Pregnancy Week
by Week - Week 28
Eyebrows and eyelashes are now very noticeable.
Hair on
baby's head is growing longer.
Eyes
are completely formed now.
Your
baby's body is getting plump and rounded. Most of that increase is
muscle tissue and bone. Fat will be added during the third trimester.
Lungs
are capable of breathing now but baby would still struggle and require
medical attention if born now.
Your
baby weighs in now at 2.2 pounds (1005gm) and is 14.8 inches (37.6cm).
The Third Trimester -
Weeks 28 to delivery.
You're in the homestretch now. This is the time for childbirth classes. As
the anticipation rises though, so may those feelings of anxiety and even a
bit of fear. Don't worry, as all these emotions are perfectly normal.
This pregnancy is suddenly very real. That due date that was once so far
away is looming ever closer. Your baby is making his or her presence known
with karate kicks, twists and turns until there simply is no more room.
The third trimester as the one where the finishing touches are added. The
majority of pregnancies run smoothly but complications such as
premature labour,
gestational diabetes, and
pre-eclampsia can occur.
Pregnancy Week
by Week - Week 29
Your
baby's head is in proportion with body now.
Fat
continues to accumulate under the skin..
Your
baby's brain can control primitive breathing and body temperatures.
Pregnancy Week
by Week - Week 30
A pint
and a half of amniotic fluid surrounds him. As he grows and fills your
uterus, the amount of amniotic fluid will decrease.
Early
lanugo is beginning to disappear that served to protect your baby's skin
from the water in the womb. Your little one's own hair may begin to
appear.
Toenails are entering their final growth stage.
Bone
marrow is now in charge of red blood cell production.
Your
baby has the capability now to produce tears.
Pregnancy Week
by Week - Week 31
The
rate of physical growth slows down just a bit, but even though she
doesn't get much longer.
Fat
continues accumulating. This layer of fat turns the skin from red to the
rosy pink of a newborn.
The
brain enters another period of rapid growth, producing hundreds of
billions of new nerve cells.
The
lungs are the only major organ left to complete development.
Pregnancy Week
by Week - Week 32
All
five senses are working. Your little one is fascinated and practicing
testing these out as much as possible!
Toenails are completely formed.
Brain
scans have shown that babies have periods of dream sleep (REM) starting
around the eight month.
Your
baby is up to 3.75 pounds (1702gm) now and is 16.7 inches (42.4cm) long.
Pregnancy Week
by Week - Week 33
Amniotic fluid is at its highest level during your
pregnancy.
Neurons
and synapses are developing in huge numbers -- forming connections in
your baby's brain will provide the skills needed to thrive as a
newborn. This week coordination of sucking and swallowing
with breathing become better developed.
While
most bones are hardening, the skull is relatively pliable and not
completely joined. The bones will be able to move slightly to make
birthing easier.
Pregnancy Week
by Week - Week 34
Antibodies from your blood continue being transferred from you. These immunities
continue to build until birth. Then breast milk will add even more
protection against disease.
Your
baby may have already turned to a head-down position in preparation for
birth. If he is your first baby, he may be settling into the pelvis with
his head pressing against your cervix.
Fingernails have reached the end of the fingertips now.
Pregnancy Week
by Week - Week 35
Most
babies born now will survive and without many long-term problems.
Fat
accumulations plumps up the arms and legs this week. These layers of fat
will help regulate body temperature. They also provide those cute little
dimples on elbows and knees.
Hearing is fully developed.
The
testes have completed their descent in males.
Pregnancy Week
by Week - Week 36
If he
hasn't already, this week your baby may drop into the birth canal
(engagement). While
breathing for mum becomes easier, walking may be the exact opposite! If he's
not your first baby, this "lightening" may not occur until right before labour.
Skin is
becoming smoother, "baby" soft.
Your
child's average size is now 18.66 inches (47.4cm) and 5.78 pounds (2622 g).
Pregnancy
Week by Week - Week 37
The
baby is now
officially full term.
Pregnancy Week
by Week - Week 38
Your
child's intestines are accumulating lots of meconium.
Circumference of head and abdomen are about the same size for your baby.
Pregnancy Week
by Week - Week 39
The
lanugo has mostly disappeared, but you'll probably find a bit on her
shoulders, arms and legs and in those protected little bodily creases.
The
lungs are maturing and surfactant production is increasing and fully
prepared.
His
body continues laying on the fat stores that will help regulate his body
temperature after birth. In addition to normal fat, a
special "brown" fat is accumulating in the nape of his neck, between
the shoulders and
around organs. Brown fat cells are important for thermogenesis
(generating heat) during the first weeks.
Pregnancy Week
by Week - Week 40
Much of
the vernix has vanished but you will notice traces on the body.
15% of
your child's body is fat.
Approximately 65 percent is water!
Small
breast buds are present on both sexes.
Any day
you will be cradling your son or daughter!
Careful management is required for
pre-existing risk factors including:
Teen Pregnancy
Obesity
Smoking
About this time, your obstetrician is likely to
recommend that
labour
be induced as there is a risk that the function of the placenta will
become inadequate.
This Website has been
developed as a result of experience gained from its sister gynaecology site -
www.2womenshealth.com.
DISCLAIMER
The aim of this web site is to provide a general guide and it is not intended as a substitute for a consultation with an appropriate specialist in respect of individual care and treatment.