Pregnancy on birth control pills may have an effect on the fetus. Pregnancy on birth control pills may have an all-or-nothing or all-or-nothing effect on the fetus. 1. All or nothing: After taking the pill, there is no increase in the rate of fetal abnormalities between women who take the pill and those who do not, but it is important to have a good checkup during pregnancy to see how the fetus is developing. 2. all there: if there are signs of miscarriage after pregnancy while taking the pill, it is recommended that there is no need to keep the baby, pregnancy should do a good job of the pregnancy of the various detector test program, once there are fetal malformations, the need to terminate the pregnancy in a timely manner. Taking contraceptive pills during pregnancy, must be strictly related to the examination, if abnormal, can be early for the appropriate treatment.