Progesterone Testing For Infertility

Table Of Contents
  1. Progesterone production
  2. Progesterone is difficult to measure
  3. Why check progesterone levels?
  4. Is there a time when treatment with progesterone is recommended?

Most infertility patients are aware that progesterone is a hormone produced by the ovaries after ovulation. Many have been told be their doctors that if their levels of progesterone are low that they will not be able to become pregnant or sustain a pregnancy. The current understanding of progesterone indicates that this is not true.  

Progesterone production

Progesterone is made from the cells that surrounded the egg during its development. They are called granulosa cells. The cells make up the wall of the cyst that contains the egg. This type of cyst is called a follicle. As the egg develops, the follicle grows and the granulosa cells increase in size and number. Before ovulation (release of the egg), these cells produce mostly estrogen. After ovulation, they still produce some estrogen but a lot more progesterone. After ovulation, the follicle cyst is called a corpus luteum cyst.

Progesterone is difficult to measure

Progesterone levels infertility

Progesterone is not made in a smooth fashion. As the picture here shows, progesterone is actually released in pulses. Since most physicians only draw blood from a patient once to check their levels, and use a level of 10 ng/mL to mark the cutoff between “good” and “bad” levels, it is easy to see how the doctor and the patient can be misled into thinking that her levels are too high or too low.

Why check progesterone levels?

Checking progesterone levels is a reliable way to determine whether a woman has ovulated. In most labs, a level above 2.5 ng/mL indicates that ovulation has taken place. Beyond that, the uses of progesterone levels are “iffy” at best. There is little medical data to support the notion that “low” progesterone levels are associated with infertility or miscarriage. However, progesterone supplementation is an easy and inexpensive therapy which is thought to be completely safe. So most infertility specialists will “err on the side of caution”.

This means that even though it is likely that most women who are told they have low progesterone levels probably don’t have a problem, the risks of treatment are negligible so why not? The problem comes from doctors not explaining this philosophy to patients and instead let them believe that they have this serious medical problem which will keep them from having a baby without treatment. Now you can rest assured.  

Is there a time when treatment with progesterone is recommended?

Yes. During treatment with fertility drugs, doctors may use medication to prevent premature ovulation. There are two groups of medications that are used for this purpose. One group is called GnRH agonists and include the medication Lupron. The other group is called GnRH antagonists and include the medications Ganirelix and Cetrotide. When these medications are used, the production of progesterone from the ovaries may be compromised. The addition of progesterone will improves the chances for pregnancy in these instances.

Measurement of progesterone levels in these treatments is not necessary.