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  • Writer's pictureZoe

Does Breastfeeding Really Prevent Another Pregnancy?

Updated: Sep 30, 2022

It is likely that you have heard before that breastfeeding is a form of birth control. You may be wondering though, if it is really that effective, or is it still possible to become pregnant while you are still breastfeeding. The answer to each of those concerns is: yes.

Breastfeeding as a form of birth control is called the Lactation Amenorrhea Method. It can be quite effective, comparable to hormonal birth control pills, IF the guidelines are followed. The CDC recommends that all of the following factors are present in order for LAM to be 98% effective:

  1. Amenorrhea, AKA, you haven't started your period yet since birth. Once you get your first period, LAM is out of the question. Something to know, though, is that you do ovulate approximately 2 weeks before your period, so it is possible to become pregnant again without ever actually getting your period back.

  2. You are fully, or nearly fully, breastfeeding. This means that you are exclusively bringing baby to your breast for almost every feeding, with no more than about 3 bottles per week, and intervals between breastfeeding sessions are no longer than 4-6 hours. Besides, it is best to feed every 2-3 hours in the daytime and max about 4-5 hours at night, anyway.

  3. Baby is less than 6 months old. LAM is only considered effective for the first 6 months postpartum. This is likely due to the fact that around 6 months, babies start to get solid foods supplementary to breastmilk, and likely will go some longer stretches between feeds, especially at night. Night feeds have an effect on your hormones, and your own body goes through changes around this time, so this criterion makes sense.

If you notice feeding behavior or expression output changes when you start your period again, do not get too worried, as this is to be expected. The flavor of breastmilk changes slightly while you are menstruating, and your hormone fluctuations will affect your supply just a bit. This should not be cause for concern in itself, and usually goes back to "normal" (what even is normal anymore?!) during the rest of your cycle.

Now that you have all the facts about LAM, you can start to decide if this form of family planning is right for you. There are other forms of birth control to choose from, which include the mini pill, hormonal and non-hormonal IUDs (progestin only, best to speak with your doctor on this), depo shot, Nexplanon, condoms, vasectomy, and tubal ligation. Each of these will have their own list of pros and cons that need to be considered.

If you have more questions about LAM, changes in feeding behavior or supply, or about other birth control methods, the it's a great idea to reach out to a lactation consultant. Feel free to submit a message on my "contact" page. I hope you have been able to get a little bit closer in your decision making, or feel a bit more prepared for what is in store for your future. I look forward to hearing from you!

- Zoe Ruaboro, IBCLC


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