Breastfeeding and Fertility: What You Should Know

by Jun 4, 2020

As a new mom you probably have your fair share of questions about postpartum. There are plenty of old wives tales and scientific studies to dig through so how do you know what to expect when it comes to breastfeeding and your fertility?

breastfeeding woman and baby

Here we’ve answered some of the most asked questions when it comes to postpartum fertility while breastfeeding.

What happens to your body during breastfeeding

While you are breastfeeding your body’s main focus is caring for your new baby and maintaining your breast milk supply. Your body releases a hormone called oxytocin which is responsible for milk production and helps suppress the hormones that stimulate the ovary to grow an egg.

When your baby attaches to your nipple they stimulate nerves that send the signal to your brain to release oxytocin which sets in motion the let-down reflex and release of breastmilk. A breast pump can’t send the same message so you must be breastfeeding for it to work as a form of birth control.

This decreased fertility occurs when you are breastfeeding exclusively or on a consistent basis. As time goes on the effect of the oxytocin is less and less until you begin to ovulate again.

What are my chances of getting pregnant while breastfeeding?

If used correctly, breastfeeding can be a very effective temporary birth control method. According to one study only 1 to 2% of women may become pregnant during the first six months postpartum while exclusively breastfeeding.

It is possible, but rare, for a woman to become pregnant while breastfeeding and before her menstrual period has returned.

Using breastfeeding as birth control

If you are going to use breastfeeding as a form of temporary natural birth control you need to ensure you are doing it correctly. Known as the Lactational Amenorrhea Method there are a few guidelines you need to follow:

  • Your baby must be younger than 6 months old
  • You have not had any spotting or a return of your menstrual period
  • You are exclusively breastfeeding
  • You are breastfeeding at least every four hours during the day and every six hours at night


If you are considering using breastfeeding as your birth control during the first six months of motherhood you should talk to your doctor. They will be able to give you all of the details about effectively using the method, help you understand if it is a good fit for your lifestyle, and plan ahead for your next form of birth control.

Return of full fertility

If you are ready to start trying to conceive again or think it is time to consider a new birth control, it is important to understand the transition back to full fertility.

Every woman’s body is different and the time it takes to return to full fertility varies as well. For some women their menstrual periods return while their baby is still younger than six months while other women might not return to regular cycles until much later.

As you begin to wean your child off of breastfeeding either by supplementing with formula or transitioning to solid foods you should begin to gradually return to full fertility.

Most women see a return of menstruation within four to eight weeks of stopping breastfeeding, but it can be much longer than that. Once your menstrual period returns your fertility should be back to normal.

Using a fertility tracker such as Mira will allow you to track your hormones to pinpoint ovulation and your return to fertility. The use of a hormone tracker isn’t recommended for the first two weeks after childbirth. During this time your HCG level remains high and could interfere with the lutenizing hormone (LH). After that time you can use the tracker even without having returned to a regular menstrual cycle and while breastfeeding.

If you are still breastfeeding and considering undergoing fertility treatments to become pregnant again, be sure to discuss it fully with your healthcare provider. Some treatments won’t affect your milk supply or the baby, but others may require you to stop breastfeeding. Your doctor will be able to discuss the specific treatment and effects for you to make the best decision for your family.

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