Whether the fetus is considered to be part of the mother, or a separate unit [Ubar (Lav) Yerech Imo]: Gittin 23b; Temurah 10b-11a, 19a, 25a-b, 30b-31a Acquiring an item as proxy for a Fetus: Ketuvot 7b
Other
Divine control of birth: Taanit 2a-b
Special fasts for the benefit of sailors, travellers in the desert, infants, and pregnant and nursing women: Taanit 27b
Considering pregnancy a life-threatening condition: Keritot 13a
Permitting a pregnant woman to eat prohibited foods: Keritot 13a