An animal was sacrifice for 'Eed without knowing it was pregnant. What is the ruling on this issue?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The majority of scholars are of the view that pregnancy is not a deficiency that makes the sacrifice un sufficient. So it is permissible to offer a sacrifice with a pregnant animal although the Shaafi'ee school considers it as impermissible. Their view is that pregnancy spoils the stomach and weakens the animal, and the purpose of the sacrifice is to get more meat. However, the view of the majority of scholars is more correct since the Shaafi'ee school lacks evidence for their view.

As regards the ruling about the foetus whether or not it is permissible to eat, if the foetus is not completely shaped, eating it is not permissible. It is also not permissible to eat it if it was completely shaped but known to be dead before its mother was slaughtered. There is no difference of opinion on this point. Nonetheless, if the foetus comes out alive, it will not become permissible to eat unless it is slaughtered as it is a separate soul and therefore it must be slaughtered according to Islamic rites. However, if the foetus comes out dead after the slaughter of its mother and it is not known that it was dead before its mother was slaughtered, but it is most likely to have died because of the slaughter of its mother, then it is permissible to eat it according to the majority of the jurists. The Prophet said: "The slaughtering of a pregnant animal is enough to make eating its foetus permissible." [Ahmad and Abu Daawood]

Allaah knows best.