Hormones play a huge part in the process of pregnancy. There is an increase in the levels of certain hormones like estrogen and progesterone. These hormones are critical during this period, as they aid in the protection and development of the fetus. Progesterone, for instance, decreases immune levels to prevent the rejection of the fetus as a foreign body. Estrogen regulates the production of progesterone over the full term. It increases uterine blood flow. It also helps in the development of the fetus. The production of the hormone prolactin also increases, as it aids in postpartum lactation. After delivery, the hormone levels rapidly decrease, which may lead to postpartum depression and other issues. Maintaining a healthy lifestyle and good emotional support can help reduce the effects of this hormonal turbulence. Harini Parthasarathy Hosur March 2011