The amniotic sac is a membrane that surrounds and protects a developing embryo or fetus. It is also commonly referred to as the "bag of waters" or the "amnion." Other synonyms for the amniotic sac include the amniotic membrane, gestational sac, embryonic sac, and fetal membrane. The sac is filled with amniotic fluid, which provides a cushioning effect for the developing baby. The amniotic sac is an essential part of a healthy pregnancy, and any damage or rupture can lead to complications. Knowing the various synonyms for the amniotic sac can be crucial in understanding medical terminology related to pregnancy and childbirth.