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Writer's pictureRachel Persson

Breastfeeding is free birth control, right?

"You can't get pregnant while breastfeeding." We've all heard this before from a loving aunt, who thinks she's just given you a tidbit of information that makes your life so much easier. Unfortunately for many women, this is not the case, and the best way to know if this could apply to you is with the use of a fertility awareness method like FEMM.

woman reclined on couch breastfeeds her child

Let's dive into why this might not be the case. First of all, we have to understand what takes place in a normal ovulation cycle, so that when we talk about breastfeeding and the hormonal suppression included there, we can understand how that deviates from the norm.

In a normal ovulation cycle, there are four major hormones that are responsible for ovulation (the release of the egg into the fallopian tube.) Those hormones are part of a delicate interplay that can be turned "on" or "off" depending on what our other hormones are doing inside our bodies. For the purposes of keeping this brief, let's just touch on two of the four major reproductive hormones: estrogen and progesterone. Estrogen is the hormone that is responsible for building up the uterine lining and the development of the follicle inside your ovaries which holds the egg. Progesterone is the hormone responsible for maintaining the uterine lining and allowing for potential implantation of an embryo.

As we approach ovulation, estrogen rises, and this thickens the lining of the uterus, and it also allows for the production of something called cervical mucus. Once our estrogen levels have been high enough for long enough, this tells our brain that it is time to release the egg, and the brain triggers more hormones that allow that to take place. After the egg has been released, the ovary begins to produce the hormone progesterone. This halts the production of cervical mucus, and maintains the uterine lining so that an embryo might implant, if fertilization took place. This hormonal symphony takes place on a regular basis in healthy women and is a vital sign of health. It tells us that your body and hormones are healthy enough to allow ovulation to take place.

So, how is this relevant to postpartum and breastfeeding?


Well, when we are postpartum and/or breastfeeding, this hormonal interplay that allows for ovulation is disrupted. To understand this better, let's take a detour and talk about what happens hormonally postpartum.

Think of postpartum, as a mini-puberty. Your ovaries are "waking up" from a period where they have not had to do much, since you were pregnant for 9 months. So, when you are postpartum and waiting for your period to return, you are essentially in that pre-puberty time again of waiting for your fertility to begin. How long it takes your specific body to return to normal after having a baby varies greatly depending on many factors, but the one we are here to discuss is- how you choose to feed your baby. During breastfeeding, there is a hormone produced called "prolactin" and this hormone allows your body to produce breastmilk. Prolactin also acts to suppress the production of estrogen, which is step one of the ovulation cycle. Each time your baby nurses at the breast, your body produces more prolactin. So, the more your baby nurses, the more ovulation suppression you will have.

Now, this sounds wonderful and sounds like breastfeeding does mean it's harder to get pregnant, so what's the issue here?


Well, the amount of prolactin needed to suppress ovulation varies from woman to woman.

What is more than enough nursing for one woman, might not be enough to delay ovulation for another.

Rachel and her sister pose cradling their pregnant bellies

I'll use myself and my sister as examples of this.

Our babies were born just two weeks apart. My sister decided to exclusively pump. It was the best decision for her family and she was a total warrior. She pumped day in and day out for what seemed like an eternity and she dealt with a massive oversupply. She was able to donate milk during the formula shortage of 2021 and still build a stash in her freezer. My sister did not see a return to ovulation until she had begun to wean from pumping at around 10 months postpartum. My situation was a bit different. I decided to breastfeed and nurse. I nursed exclusively with for around six months. I didn't use a pump until my baby was 3 months old, and then I only pumped in addition to nursing, not to skip a feeding. I dealt with challenges to, but I pushed on, determined to nurse for a year. My period came back at 3 months postpartum, and from there my supply slowly dwindled. It seemed that (based on looking at my charts) with each cycle, my body needed more and more prolactin to even produce milk at all, let alone suppress ovulation. As my baby grew and needed more milk, my body didn't suppress ovulation and I saw a return to fertile cycles around 4 months postpartum.

My sister and I share such similar genetic makeup, and yet we had completely different returns to fertility. I hope this helps to drive home the fact that the amount of prolactin needed to suppress ovulation is different for every woman, even women who share similar genetics!


So, how can you know if your body is making an attempt to return to ovulation? By learning a fertility awareness method like FEMM.

The beauty of FAMs (fertility awareness methods) is that they teach each woman to understand her own unique fertile signs. This enables her to have better insight into what her body is doing on any given day. By watching and charting your fertile signs with a method, you are able to watch as your body goes through attempts to ovulate and eventually returns to normal cycles. This allows you to make informed decisions about your health and fertility each day.


While breastfeeding and postpartum can be wild, the use of FAMs enable each woman to be more in tune with her body and can help eliminate some of that mystery that makes it seem so crazy.

If you're postpartum and wanting to learn a method, I highly recommend this quiz to get you started.

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If you're ready and want to learn FEMM for postpartum, let's connect!


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