The 35-year-old woman

is already pregnant for the fourth time, unfortunately, all three previous

pregnancies ended in miscarriage during the first trimester of pregnancy. Here,

with her fourth pregnancy, she decided on IVF (in vitro fertilization). The

absence or failure of the corpus luteum leads to insufficient natural

production of one of the hormones necessary for the maintenance and proper

course of early pregnancy. What hormone is produced by the corpus luteum?