Progesterone in early pregnancy: measuring it, giving it: when during the first trimester is it valuable to measure levels of this hormone and when is it a waste of time? Will giving your patients progesterone supplements help prevent miscarriage? Are they safe?

Key points * We can measure levels of progesterone, a hormone necessary for the survival of an early pregnanc, to document ovulation, predict pregnancy viability, and help identify ectopic pregnancy. [...]