Here are the functions of the hormones during pregnancy: 1. Oestrogen: During pregnancy, oestrogen helps in the growth of the uterus to accommodate the growing fetus and increases blood supply to the uterus. It also plays a role in the development of the mammary glands in preparation for lactation. 2. Progesterone: Progesterone is crucial for maintaining the pregnancy. It helps to maintain the uterine lining (endometrium), preventing its shedding. It also relaxes the smooth muscles of the uterus, preventing premature contractions and thus preventing early labor. Additionally, it contributes to the development of the mammary glands.