Express Post Australia Wide


Progesterone prevents pregnancy

How does Progesterone prevent Pregnancy?

Progesterone is a primary hormone coordinating your menstrual cycle and pregnancy. You need the right amounts of progesterone at the right times to become pregnant, as well as have good fetal development and a successful labor. For this reason it is a crucial hormone when the time comes to start a family.

When an egg (ovum) is released from your ovary during the menstrual cycle, progesterone levels rise, preparing your uterus lining for a fertilised egg and also helping the placenta form once pregnancy begins. During pregnancy, progesterone aids your fetus’ development and readies your body for childbirth and nursing. Progesterone levels continue rising throughout pregnancy, until your baby is born.


The powerful river reminiscent of surging progesterone


Too Much Progesterone Prevents Pregnancy

Normally, when you release an egg (ovum) during your menstrual cycle, your progesterone levels rise. This triggers a stoppage to the production of anymore eggs. But if your progesterone levels are already high, which can occur due to various factors including poor health or birth control pills, your ovaries are tricked into not releasing any eggs at all.


lunar cycle fertility cycle myth or fact


Low Progesterone Prevents Pregnancy

If your egg cell (ovum) does not become fertilised during a normal menstrual cycle – by design or chance – your progesterone levels will naturally drop. This signals your body to begin menstruation. However, abnormally low progesterone levels may trick your body into frequent or irregular menstruation. This may prevent pregnancy or cause miscarriage or early labour.



The effect progesterone can have on egg production.


What Else Does Progesterone Control?

Besides controlling ovulation and pregnancy in women, progesterone is involved in the production of other adrenal primary hormones, including cortisol, testosterone, and estrogen. All these must be in balance for good health. Progesterone imbalances can cause infertility, weight gain, low sex drive, and depressive symptoms. In men, progesterone influences sperm production and sexual behaviour.


Can High Testosterone Prevent Pregnancy?

Testosterone​ has itself been accused of messing with the menstrual rhythm so we thought we’d take a look at that. This is what we discovered.

A study* published in the Clinical Endocrinology journal (Volume 24, Issue 5) had researchers artificially increasing serum testosterone levels in a group of ovulating women whilst observing menstrual function. Observations were carried out at regular intervals over a period of 3 months via serum blood test. The results of the study showed that elevated testosterone did not influence the behaviour of Luteinising hormone (LH), Follicular Stimulating Hormone (FSH) or Estradiol (E2), in regard to the test subjects. In other words, elevated androgen / ovarian testosterone was ruled out as a potential threat to the menstrual cycle.


Rule Out the Progesterone Factor

Worry won’t help you. Facts will. Get your progesterone levels tested one way or the other if you are concerned. It can be done easily and at home. For Australian women, TestoChecker’s G2 Fertility Hormone Test Kit can be used to check the expected rise in Progesterone as well as other hormones relevant to fertility hormone health.

If your concerns relate to physical symptoms causing either physical or mental distress, consult your family doctor immediately.

We hope you found this post useful, it was originally posted in 2017 and revised on the 17th of June 2021. By…


TestoChecker®Hormone Test Kits (blog)
Phone: +61293271336
Address: L 13 465 Victoria Ave, Chatswood, NSW, 2067
Purpose:We Take the Stress out of The Test’

*Dewis P, Newman M, Ratcliffe WA, Anderson DC. Does testosterone affect the normal menstrual cycle? Clin Endocrinol (Oxf). 1986 May;24(5):515-21. doi: 10.1111/j.1365-2265.1986.tb03280.x. PMID: 3098455.

Last updated 31.03.2023.