How the baby grows in the womb

Doctors and midwives time pregnancy, not from conception but from the first day of a woman’s monthly period. So what is called ‘four weeks pregnant ‘is actually about two weeks after conception. On this timing, pregnancy lasts for forty weeks.

Of course, forty weeks is only an average .some pregnancies are usually short, while some longer.

If you are not sure about the date of your last period, then an ultrasound scan can give a good indication of when your baby will be due.

How the baby develops

In the very early weeks the developing baby is called an embryo .then from about eight weeks onwards, it is called a fetus, which means ‘young one ‘.

WEEK 3

This is 3 weeks from the day of your last monthly period...the fertilized egg moves slowly along the fallopian tube towards the womb. The egg begins as one single cell. This cell divides again and again. By the time the egg reaches the womb, it has become a mass of 100 cells and is still growing.

Once in the womb the egg attaches itself to the womb lining .this is called implantation

WEEKS 4-5

The egg now settles into the womb lining .the outer cells reach out like roots to link with the mother’s blood supply. The inner cells form into two, and later three layers. Each of these layers will grow to be different part of the baby’s body. One layer becomes the brain and the nervous system, the skin, eyes and ears. Another layer becomes the lungs, stomach and guts. The third layer becomes the heart, blood, muscles and bones.

The fifth week is the time of the first missed period, when most women are only just beginning to think that they might be pregnant. Yet already the baby’s nervous system is beginning to develop.

A groove forms in the top layer of the cells .the cells fold up and round to make a hollow tube. This is called the neural tube. It will become the baby’s brain and spinal cord, so the tube has a ‘head end ‘and a ‘tail end’. At the same time the heart is forming, and the baby already has some of its own blood vessels. A string of these blood vessels connect baby and mother and will finally become the umbilical cord.

WEEKS 6-7

There is now a large bulge where the heart is, and a bump for the head because the brain is developing. The heart begins to beat and can be seen beating on an ultrasound scan.

Dimples on the side of the head will become the ears, and there are thickenings where the eyes will be. On the body, bumps are forming, which will become muscles and bones, and small swelling called limb buds show where the arms and legs are growing.

At seven weeks, the embryo is about 8mm (1/4 in) long from head to bottom (or from ‘crown to rump’)

WEEKS 8-9

At this time, a face is slowly forming. The eyes are more obvious and have some color in them. There is a mouth with a tongue. There are now the beginnings of hands and feet, with ridges where the fingers and toes will be. The major internal organs are all developing-the heart, brain, lungs, kidneys, liver and gut.

At nine weeks, the baby is about 17mm (3/4in) long from head to bottom.

WEEKS 10-14

Just twelve weeks after conception, the fetus is fully formed. It has all its organs, muscles, limbs, and bones. From now on, it has to grow and mature.

The sex organs are now well developed. But at this early stage, it is impossible to make out the baby’s sex in an ultrasound picture.

The baby is already moving about, but the movement cannot yet be felt

By about fourteen weeks, the heartbeat is strong and can be heard using an ultrasound detector. The heartbeat is very fast –about twice as fast as a normal adult’s heartbeat. The baby is about 56mm(2 1/2in)long from head to bottom .the pregnancy may just be beginning to show, though may vary from woman to woman.

WEEKS 15-22

The baby is now growing quickly .he body and head are now more in proportion, the face begins to look more human, and the hair is beginning to grow, as well as eyebrows and eyelashes. The eyelids still stay closed over the eyes.

The lines on the skin of the fingers are now formed, finger and toenails are growing, and the baby, has a firm hand grip.

At about the twenty-two weeks the baby becomes covered in a very fine, soft hair called lanugos .this finally disappears again before birth, although sometimes, just a little is left and disappears later.

At about the 18^th-22^nd week, you will feel your baby move for the first time. If this is your second baby you will feel it move earlier, at about the 14^th to 16^th week, after conception.

At first, you feel a fluttering, bubbling or a very slight shifting movement, maybe bit kike indigestion, later you can’t mistake the movements, and you can even see the baby kicking about. You can often guess which bump is a foot or a hand.

Make a note of the date you felt the first movement; it might also be used to check your expected date of delivery.

WEEKS 23-30

Now the baby is moving about vigorously and responds to touch and sound. Sometimes the baby may get hiccups, and you can feel the jerks of each hiccup. The baby may also begin to follow a pattern of sleeping and waking, which may often be different from yours. So when you go to bed at night, the baby wakes up and starts kicking.

The baby’s heartbeat can now be heard by your partner, when he puts his ears to your tummy .the baby is now covered by a white, greasy substance called vernix.this mostly disappears before birth.

WEEKS 31-40(or 42 for later birth)

At this stage the baby is growing plumper so the skin, which was quite wrinkled before, is now smoother. Both the vernix and the lanugos begin to disappear.

By about 32^nd week ,the baby is usually lying head downwards ,ready for birth.Sometime,before birth the head may move down into the pelvis, and is said to be ‘ engaged’ ,but sometimes the baby’s head does not engage until labor has started.