Information about progesterone levels
Progesterone levels are important in a woman’s reproductive cycle. It is critical in maintaining the uterine lining so that an early pregnancy can grow normally. The follicles (egg sac) that release the egg produce this hormone.
Before ovulation, progesterone is found in low levels in the blood. After ovulation, it rises quickly, reaching a peak about one week after ovulation. This is also usually one week before the next period. Thus, for women who have regular 28 day cycles, ovulation typically occurs around cycle day 14. Progesterone then peak around cycle day 21. If pregnancy did not occur, the woman’s period will happen around cycle day 28/29.
For a woman with fairly regular cycles, a level should be done approximately one week before expected menses. It can show if she ovulated (released an egg) in that particular cycle. A level greater than 3ng/ml indicates that ovulation has occurred.
More information about this important hormone
A level drawn during a menstrual cycle is only good for indicating that ovulation has occurred. Though some providers feel that having a higher progesterone level (i.e. >10 ng/ml) is better, there is actually no good evidence that this indicates a better overall situation.
The reason is because the progesterone hormone secretes in pulses. Thus, if a woman were to have 10 progesterone levels drawn in a single day, the levels may actually vary considerably.
A better evaluation of adequate progesterone production is to look at the number of days occurring between ovulation and the very next period. If there are fewer than 12 days between ovulation and a menstrual period, this may be an indication of a progesterone problem. This is the so-called ‘luteal phase defect’. Our doctors can easily treat the problem with progesterone supplementation.
The summary of progesterone levels
In summary, a progesterone level drawn during a menstrual cycle has only 1 benefit – to show that ovulation has occurred. We have other ways of detecting ovulation – even before it has occurred: ovulation kits and ultrasound monitoring. Because these methods also allow us to time intercourse or intrauterine insemination, we frequently don’t check progesterone levels during a menstrual cycle. With pregnancy, though, we will monitor your progesterone levels closely and supplement if needed! Contact us to learn more.