List the three hormones produced in women only during pregnancy. What happens to the levels of estrogen and progesterone during pregnancy ?

The correct answer is:
- Human chorionic gonadotropin / hCG
- Human placental lactogen / hPL
- Relaxin
The level of progesterone & estrogen increases during pregnancy.

1. Hormones Produced Only During Pregnancy
During pregnancy, the maternal body undergoes significant physiological and endocrine changes to support the growing fetus. Three primary hormones are produced in women exclusively during this period:

• Human Chorionic Gonadotropin (hCG): Produced by the syncytiotrophoblast cells of the placenta shortly after implantation. It prevents the disintegration of the corpus luteum, thereby maintaining progesterone production which is critical for sustaining the pregnancy.
• Human Placental Lactogen (hPL): Also secreted by the placenta, this hormone plays a vital role in regulating maternal metabolism, stimulating breast development for lactation, and ensuring a steady supply of nutrients (especially glucose) to the fetus.
• Relaxin: While relaxin is secreted in small amounts during the menstrual cycle, its production increases significantly during pregnancy, primarily by the corpus luteum and later by the placenta. It helps dilate the cervix and relaxes the pelvic ligaments to facilitate childbirth.

2. Levels of Estrogen and Progesterone During Pregnancy
During gestation, the levels of both estrogen and progesterone increase continuously. Initially maintained by the corpus luteum under the influence of hCG, the placenta eventually takes over the production of these hormones by the end of the first trimester.

• Progesterone: Keeps the uterine lining (endometrium) thick and healthy, prevents uterine contractions that could lead to miscarriage, and prepares the breasts for lactation.
• Estrogen: Promotes uterine growth, enhances blood flow between the uterus and placenta, and regulates the production of other key pregnancy hormones.