Hello, Thanks for your query. Progestins, in general, should be withheld during pregnancy. Progestins cross the placenta. Although many studies fail to demonstrate an increase in teratogenicity when progestins are given in the first trimester, the possibility that genital abnormalities may appear in male and female fetuses exposed to progestins during that period has been suggested by some studies. The low number of abnormalities reported include an increased risk of hypospadias in male fetuses exposed to intrauterine progesterone and virilization of the female fetus external genitalia when exposed to ethisterone and norethindrone. There is some controversy about the reliability of these reports. I hope this information has been both informative and helpful for you. In case of any doubt, I will be available for follow ups. Wish you good health. Regards, Dr Arif You can consult me again directly through my profile http://www.healthcaremagic.com/doctors/dr-arif-n-khan/65133