Does Birth Control Stop Ovulation?

How Hormonal Birth Control Prevents Pregnancy

Does Birth Control Stop Ovulation?
Does Birth Control Stop Ovulation?. Photo © 2015 Dawn Stacey

Question: Does Birth Control Stop Ovulation?

Combination birth control methods (such as the birth control pill, the patch, and NuvaRing) have the main goal each month of preventing your body from releasing an egg. Sometimes, progestin-only birth control (like Depo Provera, the minipill, Mirena, Nexplanon, and Skyla) can also do this. The estrogen and/or progestin found in these methods can cause birth control to stop ovulation.

Answer: Yes, Birth Control Can Stop Ovulation

Hormonal birth control supplies a steady level of both progestin and/or estrogen every day. This steady supply of hormone helps birth control stop ovulation. Remember, in order to get pregnant, there must be an egg for the sperm to fertilize. So, when birth control stops ovulation = an egg is not released from the ovary = no egg for the sperm to join = preventing pregnancy.

The Mechanics -- How Does Birth Control Stop Ovulation?

In order for ovulation to occur, certain hormonal changes must be taking place in your body. The steady stream of hormones from your birth control stops ovulation by blocking these hormonal changes. Ovulation takes place after there is a surge of the luteinizing hormone (LH). This surge actually triggers the release of the egg from the ovary. Hormonal birth control also blocks the message sent to your brain (hypothalamus) to release gonadotropin-releasing hormone (GnRH) -- this is the hormone that signals the pituitary gland to make the follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

 So, since your pituitary gland never gets this message:

  1. It does not produce the follicle stimulating hormone (FSH), so there is no signal to trigger the the growth and development of egg follicles in the ovaries.
  2. Nothing triggers the luteinizing hormone (LH) surge,  so the egg's release is not activated and ovulation does not take place.

    So to Recap:

    • The FSH signals the growth of egg follicles in the ovaries.
    • The LH triggers your ovulation day.
    • The ovary becomes relatively inactive without these hormones present.

    The Result:

    Hormonal birth control basically keeps you  in the same phase of your menstrual cycle on a continuous basis. This is because hormonal contraceptives will continuously cause your cycle to skip the release of GnRH.

    How This All Stops Ovulation?

    Hormonal birth control stops ovulation because it prevents the signal that triggers the two key hormones that are involved in ovulation: FSH and LH. These two hormones will begin to be produced if your body notices a shortage of estrogen and progesterone. Hormonal birth control provides just enough of these synthetic hormones to prevent the stimulation of FSH and LH production. Keeping estrogen and progesterone levels constant produces constant levels of FSH and LH. These constant levels keep the egg from ripening and maturing -- so the egg is never released. By providing your body with a continual hormone supply that blocks these signals and skip over the release of GnRH, birth control stops ovulation from taking place.

     

    Source:

    Norman R. "The human menstrual cycle." The Active Female. Springer New York, 2014. 61-66. Accessed via private subscription.

    Back to Main Page: Hormonal Birth Control Questions

    Back to Next Question: What if Hormonal Birth Control Fails and Ovulation Occurs Anyway?

    Continue Reading