What are the primary hormones involved in pregnancy?

The primary hormones involved in pregnancy include estrogen, progesterone, and human chorionic gonadotropin (hCG), making this choice the most accurate.

Estrogen plays a crucial role in maintaining pregnancy and promoting fetal development. It helps in the growth of the uterus and enhances blood flow to the placenta, facilitating nutrient transfer to the developing fetus. Progesterone is essential for establishing and maintaining the uterine lining, which is vital for supporting the implantation of the embryo and preventing uterine contractions during the early stages of pregnancy. Human chorionic gonadotropin (hCG) is produced shortly after the embryo implants in the uterus; it signals the ovaries to continue producing progesterone and estrogen, thus helping to maintain the uterine environment for the developing fetus.

The other selections include hormones that are either not directly related to maintaining pregnancy or not primary in the context of pregnancy. For instance, testosterone, while important in other contexts, does not play a significant role in human pregnancy, and oxytocin is more associated with labor and lactation. Cortisol, although it does have roles in various physiological processes, is not a primary hormone in pregnancy. Insulin is involved in regulating blood sugar and does play a role during pregnancy, but it