Which type of progesterone support is best for IVF?

This study compared progesterone injected under the skin to vaginal progesterone after an embryo transfer. It found that under-the-skin progesterone was just as effective as vaginal progesterone, and led to similar pregnancy rates.

In vitro fertilization (IVF) is a common infertility treatment that involves transferring embryo(s) into the uterus. To establish a pregnancy, the embryo needs to implant in the lining of the uterus. It is necessary for the uterine lining to stay thick during the luteal phase, the second half of the menstrual cycle when the embryo is implanting. However, it is common for IVF cycles to have luteal phase defects, in which there is not enough support for the lining of the uterus.

Because of this, additional progesterone is provided after an embryo transfer in IVF cycles. The most common method is vaginal progesterone. However, progesterone can also be given as injections under the skin (subcutaneous). It is not clear whether injections are as effective as vaginal progesterone.

This study used records from 195 women who underwent 273 cycles of IVF. 197 cycles used vaginal progesterone, while 76 cycles used injections under the skin. The two groups had similar ages, body weights, and IVF protocols.

A similar number of patients became pregnant per IVF cycle in both groups (vaginal: 36.5%; injection: 39.9%). Early miscarriage was also similar in both groups (vaginal: 35%; injection: 39.5%).

This study found that under-the-skin injections are equally effective as vaginal progesterone for women undergoing IVF.

The patients chose which type of progesterone to use, rather than being assigned by the researchers. Also, different medications protocols were used to stimulate the ovaries, which may affect the luteal support of progesterone.

If you are undergoing IVF, discuss with your doctor which type of progesterone treatment would be easier for you.