Yevamos 7:2-3

Yevamos 7:2                                                         

If the daughter of a Yisroel (an Israelite) is married to a kohein and she brought slaves into the marriage, whether they are of her father’s house or part of her dowry, they may eat terumah. If the daughter of a kohein is married to a Yisroel and she brought slaves into the marriage, whether they are of her father’s house or part of her dowry, they may not eat terumah,

Yevamos 7:3

If the daughter of a Yisroel is married to a kohein and he died while she was pregnant, her slaves (of the dowry type) may not eat terumah because they are to be inherited by the unborn child. An unborn child can keep slaves from being able to eat terumah (in the case of the daughter of a kohein is married to a Yisroel) but cannot bestow the right to eat terumah (in our case). This is the opinion of Rabbi Yosi. The Sages said to him that once he addressed the case of the daughter of a Yisroel is married to a kohein, then even if the daughter of a kohein is married to a kohein who dies while she’s pregnant, the servants should not be able to eat terumah because of the unborn child.