Progesterone value during the cycle and in pregnancy: how it varies and what it can tell us
What are the normal progesterone values after ovulation and in early pregnancy? And when is the value considered adequate for embryo implantation?
The evaluation of the progesterone values in the blood allows us to understand whether ovulation has taken place and to establish whether the endometrium is favorable for the engraftment of the embryo.
Progesterone, in fact, is essential for the good course of pregnancy , as it makes the uterine environment favorable for implantation and the continuation of the pregnancy.
For these reasons, the dosage of progesterone in the blood is one of the tests usually prescribed for the diagnosis of infertility , to understand whether the woman ovulates or not, and during medically assisted procreation (MAP) , to verify that there is no excessive hormone production that can prevent implantation.
How do progesterone levels vary during the cycle?
Progesterone is produced in the event of ovulation by the corpus luteum , which forms in one of the two ovaries after the follicle that contained the oocyte bursts.
Once ovulated, progesterone continues to increase for about 6-10 days and then, if the oocyte has not been fertilized, it gradually decreases.
The increase in basal body temperature that is monitored by building the basal temperature graph is precisely caused by the higher levels of progesterone in the circulation.
In a non-pregnant woman, progesterone levels about one week after ovulation (around day 21 in a 28-day cycle) are usually at least 8.8 to 10.5 ng/ml (nanograms per milliliter). . Much lower levels can indicate a failure to ovulate .
During a medically assisted procreation cycle , it is essential to monitor progesterone values. Also, if a progesterone deficiency is suspected , doctors typically recommend dosing the progesterone about 6 to 8 days after ovulation .
Levels of this hormone can change from day to day and from hour to hour. Therefore, in the presence of a single abnormal value, the doctor may request a repeat test. In particular, after eating, progesterone values can drop by up to 50%, which is why the sampling should be done in the morning and on an empty stomach .
Progesterone values in the absence of pregnancy
In the preovulatory phase (follicular phase) : less than 0.89 ng/ml
During ovulation : less than or equal to 12 ng/ml
In the post-ovulatory phase (luteal phase) : 1.8 to 24 ng/ml
Post menopause : less than 1 ng/ml
Value of progesterone for engraftment
In PMA treatments, a progesterone value lower than 1.5 ng/ml in the late follicular phase is considered adequate for the engraftment of the embryo. Higher values are rarely accepted and in any case no more than 2 ng/ml.
Progesterone levels in early pregnancy
When a woman becomes pregnant , progesterone production increases instead of decreasing (as it usually does after ovulation).
At the beginning of pregnancy , progesterone values rise to at least 10-12 ng/ml. To have a better chance of a successful pregnancy, however, most doctors want levels of 16-18 ng/mL or higher , even though many pregnancies continue successfully despite lower progesterone levels.
In case of an ectopic pregnancy the progesterone values are lower than in an intrauterine pregnancy.
That said, the test commonly used to assess whether pregnancy has begun is the beta hCG dosage and not the progesterone dosage.
Table of progesterone values in pregnancy
Trimester of pregnancy | Progesterone value |
1st quarter | 11.2-90.0 ng/ml |
2nd quarter | 25.6-89.4 ng/ml |
3rd quarter | 48-150 to 300 or more ng/ml |
Note: ng/ml = nanograms per milliliter
In case of a twin pregnancy , the values could be higher .
Warnings: Reference value ranges may vary slightly between different laboratories. Whenever you consult the results of the tests done, always speak to your doctor to have a correct interpretation of the results .
Kathryn Barlow is an OB/GYN doctor, which is the medical specialty that deals with the care of women's reproductive health, including pregnancy and childbirth.
Obstetricians provide care to women during pregnancy, labor, and delivery, while gynecologists focus on the health of the female reproductive system, including the ovaries, uterus, vagina, and breasts. OB/GYN doctors are trained to provide medical and surgical care for a wide range of conditions related to women's reproductive health.