Life Before Birth

Life Before Birth

Pregnancy is divided into 3 equal blocks called 'trimesters'. In the first trimester, up to 9 weeks, the foetus will form a complete human body with limbs, nerves, organs and muscles. This is the most fragile part of the pregnancy when the foetus is most at risk. After around 2 months the whole body begins to move and twitch. The placenta has formed and has taken over from the yolk sac the job of providing nourishment for the embryo. The intestines are formed and the foetus can move its legs and head but the eyes remain fused shut. Even at this early stage the foetus responds to stimulation – when prodded its tiny hands will close – and this is the point at which its own heart beat can be heard with a stethoscope. In fact 4D scans reveal that the foetus can already suck, yawn and swallow - possibly all automatic reactions. Is the foetus practicing for when it will burst in to the real world? At about 9 weeks the foetus starts announcing its existence with a series of leaps, using the walls of the uterus like a trampoline. This early on there is still plenty of space in which to flex its muscles. By the end of the first trimester everything is in place – ready to develop and grow.

Throughout the 2nd trimester the limbs start to function more fully. Now there is much less risk of miscarriage. The fist normal ultrasound scan takes place around 11-14 weeks to establish an accurate delivery date and to measure the crown to rump length and make sure everything is okay. The scan could reveal Downs Syndrome or other genetic abnormalities. It might also reveal twins. In fact twins are fascinating because their close bonding starts in the womb where there is close contact of arms, legs and mouths. Non identical twins are separated by a membrane as there are two separate placentas. Multiple births run in families – if your mother had twins then you are more likely to have them too. At the fist scan this is always a shock, but also a delight to the families – especially when they can hear two distinct heart beats. At 10 weeks the genitals can be clearly seen, but it is still hard to be sure if it is a boy or a girl. In a girl the tiny ovaries are already producing her lifetime supply of eggs and in a boy the rudimentary testicles are already producing testosterone.