Progesterone Support in IVF
Progesterone is critical for the establishment and continuation of a successful pregnancy. Exogenous progesterone has been given in IVF since IVF’s inception. The reason was thought to be due to the removal of cells from the ovary that produced progesterone at the time of egg retrieval. Later when IVF cycle stimulation included drugs such as Lupron, Ganirelix, or Cetrotide progesterone had to be given due to down-regulation of progesterone caused by these drugs that could linger for weeks after discontinuing them following egg retrieval.
There are no definitive answers as to when to start and stop progesterone supplementation. There is also no definitive consensus as to which formulation (IM injection, vaginal gel, vaginal suppositories) of progesterone works best except that oral formulations are ineffective. IVF centers have their own progesterone supplementation protocols that work best for them. However, most Reproductive Endocrinology and Infertility Specialists would agree that no matter the formulation chosen for progesterone support, progesterone supplementation should start within two days of egg retrieval and continue until at least the 9th week of pregnancy.
There is no benefit in obtaining random blood levels of progesterone. This is because progesterone secretion fluctuates within brief time periods throughout the day. There is also no consensus on minimum progesterone concentrations that define normal luteal function. Progesterone levels in the blood do not correlate with levels within the uterus and are thus unhelpful in determining the need for or effect of luteal support.