Does Regestrone adversely affect the growing embryo?
Q: My wife is 34 years old and has hypothyroidism. We have a 3 years old boy and recently we started planning for another baby. She missed her period last year, so we tested for pregnancy and it was negative and our gynaecologist prescribed Regestrone tablets for 5 days (twice daily) to regularise her periods. She still did not get her periods and this time we went to another doctor, who said that she is pregnant and did a scan and reported 8 weeks of pregnancy. I asked the doctor if Regestrone will have any adverse effect on the growing embryo? Is it safe to proceed with this pregnancy?
A:The use of Regestrone (norethindrone) is not permitted during pregnancy. Since there are cases of false negative pregnancy tests (i.e. test shows negative but the woman is pregnant), one should do 2-3 tests to exclude pregnancy before prescribing Regestrone. When Regestrone is given in high doses at the time of the development of external genitalia (from Day 45 of pregnancy onwards), the female fetus may show signs of musculanisation (male characters such as hair on unwanted places) but no problem in male fetus. Apart from this no adverse effects have been reported. Since in your wife's case, (a) the dose was not high, (b) Regestrone was given before Day 45, it is pretty safe to continue with pregnancy.