3,296. A Fetus Disqualifies but Does Not Enable

Terumos 8:2

A fetus (in halacha 8:1) is as follows: If the daughter of a Yisroel is pregnant from a kohein, the fetus does not enable her to eat terumah; if the daughter of a kohein is pregnant from a Yisroel, the fetus does prohibit her from eating terumah. [Hence, a fetus can disqualify a woman from eating terumah but not enable her to do so.] This halacha is inferred from Leviticus 22:13, which says “she shall return to her father’s home as in her maidenhood,” which excludes a pregnant woman.

Terumos 8:3

If a Yisroel is intimate with the daughter of a kohein, we do not assume that she is pregnant. Rather, she can immerse in a mikvah and eat terumah that very evening. If the daughter of a kohein was married to a Yisroel and he died, she can immerse herself and eat terumah that very evening and for 40 days. If she is later found to be pregnant, her eating terumah is only problematic from the fortieth day and on. This is because an embryo isn’t considered a fetus for the first 40 days.