Can You Get Pregnant While Breastfeeding?

If you’re an expecting mom, you may have heard that once your baby is born (once you’re over “the bump”), you’re free to enjoy intimacy with your partner without worrying about bundle #2 plotting their arrival.

But how much truth is there to the lore? After giving birth, many women wonder, can you get pregnant while breastfeeding?

In a nutshell, yes. During the first few months postpartum, the hormones behind breastfeeding do suspend fertility and ovulation. However, your regular reproductive cycles usually kick back into gear around 6 months into nursing—and it isn’t always clear when you’ll start ovulating again.

While using this period of suspension as birth control is possible (it’s known as the lactational amenorrhea method), it’s crucial to understand how postpartum hormones, the LAM technique, fertility, and your body work together to keep you covered.

What is the lactational amenorrhea method of birth control?

The lactational amenorrhea method (LAM) is a proven approach to family planning with endorsements from institutions like the ACOG and the CDC. In essence, it relies on the hormones your body naturally produces during and after pregnancy to ensure you don’t conceive again if you don’t want to.

Used correctly, LAM averages a 99% efficacy rate for pregnancy prevention—but it’s strictly considered a transitional contraceptive. In other words, it can only be used effectively in the short term. (And you’ll probably want to keep some other methods of family planning in your arsenal to give you the maximum amount of control).

LAM’s high efficacy rests on meeting the following three conditions:

1. The mother’s regular ovulation and menstrual cycles must still be suspended (aka, you haven’t gotten your period yet).
2. The mother’s baby is fewer than 6 months old.
3. Nursing babies are only breastfed, with feeding taking place at least twice a day (in the daytime and in the evening). Ideally, your baby will nurse whenever they’re hungry.

Crucially, LAM is not considered a reliable birth control method beyond 6 months into the postpartum period. And, within those 6 months, using it correctly requires a thorough understanding of how the hormones behind breastfeeding interact with your reproductive cycles.

How (and How Long) Breastfeeding Suppresses Ovulation

The CDC recommends nursing your baby for at least 6 months after they’re born, though plenty of moms continue to nurse until their little one turns 2 years old (or older!).

Regardless of how long you want your baby to nurse, breastfeeding requires significant work on your body’s part. Most of that work revolves around the hormone prolactin, which moves through a series of phases to initiate, maintain, and wrap the breastfeeding period:

• Phase 1 Lactogenesis (During Pregnancy) – Your body begins making prolactin early in your second trimester, around the 16-week mark. You’ll know it when you see it: your breasts will swell, your areolas will dilate, and your nipples will get darker or change in hue. You might also notice some secretions coming from those little bumps on your nipples known as Monogomery glands.

All this is totally normal—it’s a sign your body is prepping the kitchen for a future loyal customer.

• Phase 2 Lactogenesis (Early Postpartum) – After you’ve given birth, the estrogen and progesterone that helped facilitate the final stretch of your pregnancy plummet. From there, prolactin takes over, cueing your body to produce more milk. Some women notice a dramatic change at this stage: breasts can feel heavy and tender and appear engorged. It’s not a comfortable phase, but it’s a surefire sign prolactin has kicked into high gear.
• Phase 3 Lactogenesis (Later Postpartum) – From here, prolactin’s main responsibility is to keep your breast milk supply flowing. In brand-new moms, this period is known as a state of hyperprolactinemia. If your baby continues to nurse and withdraw milk from your mammary glands, your body picks up on those cues: it’ll continue to produce prolactin to keep the supply chain going.

While all this is happening, prolactin has a crucial secondary effect: lactational amenorrhea, which keeps you from resuming your normal ovulatory cycles while you’re lactating. Prolactin does this by suppressing the production of LH (luteinizing hormone). This is the hormone that helps develop the eggs in your ovaries, spurring ovulation and ultimately re-initiating your menstrual cycle.

On average, lactational amenorrhea lasts for about 6 months. But this period can be highly elastic and varies from woman to woman, so it’s not always easy to determine when you’ll resume ovulating.

For this reason, it is still possible to conceive within those 6 months of using LAM if ovulation kicks in earlier. Remember, pregnancy can easily disrupt your pre-pregnancy ovulation cycles, so basing your predictions on your previous menstrual schedule isn’t a reliable measure of prediction. As such, the ACOG advises women to plan ahead by deciding on what secondary method of birth control they’ll use while they’re still pregnant.

Which factors can lead to pregnancy while breastfeeding?

Experts stipulate those three aforementioned conditions must be in place in order for LAM to prevent pregnancy. However, there are also several common nursing habits and practices that may impair its efficacy as a contraceptive.

Infrequent or Irregular Breastfeeding

Your body determines how much prolactin it will make according to how often your breasts are emptied of its milk supply. And the more frequently milk is withdrawn, the more your body will produce to replenish it.

This is why nursing frequency is so vital to ensuring LAM works: If your baby nurses very frequently, your body will know to continue milk production (the simple supply and demand principle!).

Ideally, you’ll empty your breasts:

• At least every 4 hours in the daytime
• Every 6 hours in the nighttime

Supplementary Feeding (Feeding Your Baby with Both Formula and Breastmilk)

LAM is only considered effective at preventing pregnancy if you are exclusively breastfeeding your baby.

If you’re alternating between breastmilk and formula, your body receives the message that “demand” is in decline. This can cue your prolactin supply to taper off, causing your ovulation cycles to resume.

If supplementary feeding will be a part of your feeding practices, just be sure to use a secondary method of contraceptive to ensure you stay covered.

Using a Breast Pump

“Emptying” your breasts may mean nursing your baby or using a breast pump so you can feed them later. However, breastfeeding is considered much more reliable for sustaining lactational amenorrhea, since stimulation from your baby’s suckling contributes significantly to prolactin production.

LAM can still work if you use a breast pump, but there are occasions when it can interfere with its efficacy. The best way to enhance its effectiveness is to pump on a regular schedule, with the same frequency as you’d nurse your baby. This can help communicate to your body to continue breast milk production.

Does LAM have any benefits?

Yes! In addition to preventing unwanted pregnancy, LAM and breastfeeding are associated with several health benefits for both mom and baby:

• Supporting maternal postpartum health – Breastfeeding may help promote emotional well-being in what can be a difficult refractory period after pregnancy. Not only can breastfeeding reduce depressive and anxious symptoms, but it’s also been shown to lengthen sleep durations (hard to come by given newborns’ round-the-clock feeding schedule!).

Importantly, postpartum depression can make it difficult for many moms to nurse their babies. If you’ve been struggling with depressive symptoms, consider reaching out to a healthcare provider. They can help you discern whether the LAM method is right for you and explore treatment modalities to help support your emotional health.

• Lowering infant health risks – From lowering babies’ rates of infection to suppressing their risk of sudden infant death syndrome (SIDS), breastfeeding is a widely recommended practice that can yield positive results for your baby’s health. Research also indicates that it can be a vital protective measure against infant mortality rates overall.
• Promoting long-term child development – The health benefits of breastfeeding don’t stop once your baby starts eating big-kid foods! Breastfeeding is a vital part of successful neurological development, which can have long-term implications for your child’s future. In one survey, infants who breastfed at least until the age of two were found to have higher cognitive outcomes than those who don’t drink breast milk.

Finally, both prolactin and oxytocin are released during breastfeeding, helping moms feel connected, loving, and loved by their babies. And while it isn’t the only way to create closeness with your child, it can be one profound evolutionary way newborns connect with their mothers.

So, if you choose to use LAM for those first precious months after they’re born, think of it as a way of giving them your complete, undivided attention (with no little siblings to steal the show).

Move Confidently into Motherhood with SneakPeek

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This post has been reviewed for accuracy by:

Sarah Cacia

Sarah Cacia, currently leading as the Director of Business Development at Gateway Genomics, parent company of SneakPeek, brings an impressive blend of bioengineering expertise and clinical business acumen. Her extensive experience, marked by roles at renowned institutions like Genentech and UC San Diego's Cardiac Mechanics Research Group, underpins her deep understanding of biotechnology and clinical research. A UC San Diego alumna with a Bachelor of Science in Bioengineering: BioSystems, Sarah's rich professional background empowers her to provide authoritative insights into the cutting-edge developments in the field.

Sources:

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3. National Library of Medicine. Lactational amenorrhoea method for family planning. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6823189/
4. Centers for Disease Control. FAQs. https://www.cdc.gov/breastfeeding/faq/index.htm#howlong
5. Cleveland Clinic. Lactation. https://my.clevelandclinic.org/health/body/22201-lactation
6. National Library of Medicine. Lactational Amenorrhea: Neuroendocrine Pathways Controlling Fertility and Bone Turnover. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8835773/
7. Science Direct. Lactational Amenorrhea. https://www.sciencedirect.com/topics/medicine-and-dentistry/lactational-amenorrhea
8. National Health Service. Natural family planning (fertility awareness). https://www.nhs.uk/conditions/contraception/natural-family-planning/
9. Fertility Appreciation Collaborative to Teach the Science. Lactational Amenorrhea Method (LAM). https://www.factsaboutfertility.org/wp-content/uploads/2014/09/LAMPEH.pdf
10. National Library of Medicine. The physiological basis of breastfeeding. https://www.ncbi.nlm.nih.gov/books/NBK148970/