PREGNANCY: RARE CAUSES OF BLEEDING

Worth mentioning is a rare condition called a molar pregnancy or, to give its full name, a hydatidiform mole.

This rather unpleasant sounding condition occurs in about one in 750 pregnancies in Australia. (It is more common in some other areas, like South-east Asia and Mexico.) What happens is that a fertilised egg may start off doing the right things, heading down to the uterus and implanting, but when it comes to dividing up into a placenta, sac and embryo, things go wrong. The embryo rarely develops, but what happens is that the chorionic villi, which usually go towards making up part of the placenta, overgrow. The overgrowing villi form cysts, creating a mass within the uterus, which enlarges more rapidly than a normal pregnancy would.

If a woman has a molar pregnancy, she may have exaggerated symptoms of pregnancy (such as marked morning sickness) and may have bleeding in early pregnancy. This is because the abnormal molar tissue produces increased levels of pregnancy hormones, and has a tendency to bleed. When she is examined, her uterus would generally be larger man it should be for the gestation of her pregnancy. An ultrasound would be performed, which would confirm the lack of a foetus, and the presence of this abnormal tissue. The treatment required is to remove the abnormal tissue, and this is done by a D and C.

Follow up is needed to ensure that all the molar tissue has been removed. Regular measurements of the level of HCG (the hormone measured in routine pregnancy tests) will monitor the regression of the condition. In most cases treatment will have been adequate. It is recommended that women wait eighteen months to two years before becoming pregnant again. There is usually no problem in subsequent pregnancies.

There is a tiny (3 to 5 per cent) chance of the molar pregnancy developing into a more serious condition, a form of cancer called choriocarcinoma (which fortunately usually responds well to treatment); another reason regular follow up is routine.