Is it safe to take Gestin (progesterone) during pregnancy?

Q: I have been treated twice for benign endometrial polyp using hysteroscopy during a span of two years. We tried to concieve after that but failed. Then the doctor recommended HSG (tube test). After four months of this test, I concieved in a natural way. This is my second pregnancy. The first one was normal. On consulting the same doctor I was recommended folic acid (5 mg) a day and Egene (two tablets a day). After taking Egene for one month I started getting indigestion, constipation and severe nausea. The doctor then changed it to Gestin (5 mg/twice a day). I am taking it for two months now. I am in the 21st week now. The ultrasound shows normal growth as per the doctor. While searching the net I came accross sites describing harmful effects of this hormonal tablet. Please advise. 1. My question is whether the prolonged use of Gestin have any adverse effects on me or the baby? 2. Shall I stop taking it now without harming my pregnancy? 3. Is it safe to have pregnancy after hystrioscopy and HSG and whether my age has anything to do with these facts?

A:Gestin is the brand name. It contains a hormone called allyloestrenol - a progesterone. It is given by some gynaecologists to maintain pregnancy in certain specified, selected cases in those women who have documented deficiency of this hormone.This hormone has no role in those women where there is no proven deficiency. This hormone is given for about 12 to a maximum of 16 weeks. After that the body produces enough and hence should be discontinued. Excessive progesterone levels in pregnant woman can lead to adverse effects, some of them quite serious.