During pregnancy, corpus luteum is maintained by

Placenta also acts as an endocrine tissue and produces several hormones like human chorionic gonadotropin (hCG). It rescues corpus luteum from degeneration.  Corpus luteum secretes progesteron which is required to maintain the endometrium during pregnancy.FSH and LH are low during pregnancy.In preparation for childbirth, relaxin relaxes the ligaments in the pelvis and softens and widens the cervix. It is high during last trimester of pregnancy.