What is the foetal ejection reflex and which hormones does the placenta produce?

The foetal ejection reflex, also known as the Ferguson reflex, is a neuroendocrine positive feedback mechanism that occurs during childbirth. When the fully developed fetus is ready for delivery, its head pushes against the cervix, triggering stretch receptors in the cervical walls. These receptors send signals to the mother's hypothalamus, which stimulates the posterior pituitary to release oxytocin. This hormone causes strong uterine contractions, which further push the fetus against the cervix, creating more stretch and triggering even more oxytocin release. This positive feedback loop continues until the baby is born.

The placenta produces several crucial hormones during pregnancy, including human chorionic gonadotropin (hCG), which maintains the corpus luteum and pregnancy in early stages; human placental lactogen (hPL), which helps regulate maternal metabolism and prepares mammary glands for lactation; estrogen, which stimulates uterine growth and prepares the mother's body for childbirth; and progesterone, which maintains the uterine lining and prevents uterine contractions during pregnancy.