Visible signs of Pregnancy
How does the womb accommodate the ever- increasing size of the pregnancy?
The progressive change in the size of the uterus to accommodate pregnancy is one of the wonders of nature. The uterus increases in weight almost twenty-five to thirty times from, about 30-50 g before pregnancy to about 1000 g (1 kg) at term. While the capacity of the uterine cavity when not pregnant is about 4-5 ml, this is increased almost a thousand-fold at term. The tiny structure, smaller than a woman's fist, grows to accommodate a baby, placenta and fluid with a combined weight of anything up to 8 kg or even more (such as in multiple pregnancy).
When does the pregnancy "bulge" first become visible?
To the outside world, there is no tell-tale abdominal bulge before twelve weeks of gestation. This is because, up until this point, the pregnancy is entirely pelvic. An exception is in the case of twins or other forms of multiple pregnancy, where the bulge may appear earlier.
Even in a singleton pregnancy, there may not be any visible distension before eighteen to twenty weeks, depending on the woman's build. After this mid-way stage, the abdomen actually distends and the increase in size is immediately apparent.
How come some women's pregnancies are hardly visible even at term while others look huge?
A combination of factors is actually at play. The size of the bulge will depend on the size of the contents of the uterus (twins will produce a bigger bulge at a comparable gestation) but this is not the only factor. The state of the abdominal muscles and their ability to rein in the growing uterus is also important. Another factor is the amount of fat deposited under the skin on the abdominal wall. This may be big enough to influence the outward impression of the size of the pregnant abdomen. Contrary to popular belief, the apparent size of a pregnant abdomen is actually a poor guide to the size of the baby.
What sort of changes are expected to the lower genital tract in pregnancy?
There is a dramatic increase in the blood supply to the vulva and vagina. These areas become engorged and the vagina increases in length and ability to stretch, in preparation for the eventual delivery.
In some cases, this may become a problem, with development of varicose veins on the vulva. This can become extremely uncomfortable and it is not possible to cure them before delivery.
There is usually increased vaginal discharge, which may alarm some women.
Apart from the physical changes, there is significant lowering of the vaginal pH, making it more acidic. This helps prevent bacterial infections. However, the flip-side to this is that it promotes the flourishing of thrush, a problem that is quite common in pregnancy. While vaginal thrush does not endanger the pregnancy, it can be a major and protracted nuisance to the pregnant woman.