Failed contraceptive and pregnancy

I had a patient who recently conceived after taking oral contraceptives. The failure rate is very low in the order of 0.01% but it does happen. One has to be careful and counsel that sometimes this can happen when one just starts taking the oral contraceptive pill and that certain antibiotics taken together with OCs can lower it's effectiveness. The dilemma is whether the pill will have any effect on the pregnancy. OCs are a category C drug ie it has shown to have effects on animals and on humans. It has been shown to have virilising effects on a female foetus. However one should not jump straight to having an abortion, as the findings are sporadic and there are many women who have taken progestogens in pregnancy without any effect on the foetus. One has to consider the effects of an abortion and weigh the risks viz. damage to the cervix, damage to the lining of the womb, infection and blockage of the tubes, against the risks of a virilising effect on the foetus.The patient has decided to continue with the pregnancy and in my opinion this was the wiser decision.