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Can you get pregnant while breastfeeding?

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Written by Cara Sumner

Cara Sumner

Cara Sumner is an accomplished writer with more than ten years of experience writing on subjects including skincare, sustainability, health, and wellness. Now, she’s dedicating her days to bringing more awareness and education to female reproductive health in her role at Natural Cycles. Cara holds a Master's Degree in Social Anthropology from Stockholm University and Minored in Female Studies/English Literature while getting her Bachelor of Arts Degree from Radford University in the States. On the weekends, you'll find her forest bathing in the woods around Stockholm.

Medically reviewed by Jack Pearson, Medical Affairs Manager at Natural Cycles

Jack Pearson

Dr. Jack Pearson is a previously HCPC registered Embryologist with a PhD in reproductive medicine. Prior to joining Natural Cycles leading Medical Affairs, he worked for more than 10 years in a clinical setting working at some of the busiest fertility clinics in the UK. Today he spends most of his time working with experts at the world’s leading institutions to carry out important research with the vision to further the field of female health. He earned his PhD from the University of Sheffield specializing in Sperm Metabolism and currently lives in London.

The simple answer is yes. Even if your period hasn’t returned, you can get pregnant while breastfeeding. But it’s a bit more complicated than that. In this article, we’ll unpack fertility while breastfeeding, the chances of getting pregnant if you’re breastfeeding, and how some people use breastfeeding as a method of birth control.

Is it possible to get pregnant while breastfeeding?

Yes, you can get pregnant while breastfeeding, even if you haven’t had your first menstrual cycle since giving birth. However, if you are exclusively breastfeeding — feeding your baby only breast milk at least every 4 hours during the day and every 6 hours at night — your body naturally stops ovulating. And if you’re not ovulating, then you can’t get pregnant.

Can you ovulate while breastfeeding?

You’re extremely unlikely to ovulate in the first few weeks after giving birth. With that said, it doesn’t mean you won’t ovulate or conceive. A 2023 study from Natural Cycles found that 19% of women who exclusively breastfed experienced their return of menstruation within three months of giving birth (this differed for those who chose to pump or bottle feed). While 76% of women who only breastfed had their period return within one year. 

Unfortunately, it’s difficult to know when that first ovulation after pregnancy will occur — you might not know it’s happened until your period returns, by which point you’ve already been fertile. There are a couple of options available to help you detect ovulation. LH tests can detect a surge in luteinizing hormones before ovulation, and taking your basal body temperature can confirm ovulation has happened. 

Is it safe to continue breastfeeding if you get pregnant?

It is considered safe to continue breastfeeding if you become pregnant. However, breastfeeding stimulates the release of oxytocin — a hormone that causes contractions and helps the uterus return to its pre-pregnancy size. For this reason, some women are concerned that breastfeeding while pregnant may cause early pregnancy loss or preterm labor, though this is rare and typically not associated with breastfeeding. 

It's normal to experience some cramping while breastfeeding, especially in the first few weeks after delivery. If you're concerned about painful, consistent cramps, don't hesitate to speak with a healthcare professional. 

If you become pregnant while breastfeeding, you can continue breastfeeding without harming your child or unborn baby. However, most doctors advise patients to wait at least 18-24 months after giving birth before conceiving again to reduce the risk of pregnancy complications and give their bodies time to recover.

Is breastfeeding a form of birth control?

Breastfeeding can be used as a natural birth control method. For centuries, people have been using the lactational amenorrhea method (LAM) — lactation refers to breastfeeding, and amenorrhea refers to not having a menstrual cycle — to stop ovulation and help prevent pregnancy. With that being said, breastfeeding isn’t a long-term contraceptive and is only a reliable form of birth control when done in a certain way for a restricted period of time. 

How does breastfeeding prevent pregnancy?

Each time your baby nurses, the nerves in your breast send signals to your brain, releasing the hormones oxytocin and prolactin into your bloodstream. These hormones are responsible for your milk production and cause breast milk to flow from your ducts, also known as the let-down reflex. Research indicates that elevated levels of these hormones also delay the release of an egg from the ovary. This means when you exclusively breastfeed, you’re naturally postponing ovulation, which can help you to prevent pregnancy.

How effective is breastfeeding as birth control?

If used perfectly, breastfeeding as a birth control (LAM) can be up to 98% effective in the first six months. This means you are only giving your baby breast milk, and only for the initial six-month period after you’ve given birth. After this time, the chances of becoming pregnant will increase. Of course, this varies from woman to woman. For some, it might take a longer time for ovulation to resume, and once it does, there is a risk you might get pregnant. Breastfeeding as a form of birth control becomes less effective as the months progress and your fertility returns. 

If we compare birth control effectiveness, for the average couple who has regular sex without using any protection, there is an 85% chance they will conceive within a year. Again, if you are breastfeeding exclusively, then LAM will halt your ovulation during the first six months of postpartum, giving you ‘protection’ against pregnancy at this time. However, this method of birth control is not effective if you are using a breast pump instead of exclusively breastfeeding. And if your baby is breastfed while being formula-fed, this may not be a suitable contraception for you. 

How do I start using breastfeeding as birth control?

You can start using LAM as soon as your baby is born. For breastfeeding to work as an effective form of birth control, you must:

  • Nurse your baby at least every four hours during the day
  • Nurse your baby at least every six hours during the night
  • Breastfeed your baby (from the breast only — breast pumps, bottles, baby formula, and solid foods may interfere with the effectiveness)

If your goal is to prevent pregnancy, it is important to remember that breastfeeding as a form of birth control is less effective once your baby turns six months old or your period returns. 

Using birth control while breastfeeding

If you don’t want to start using LAM, it’s important to talk to your doctor about your contraceptive options postpartum. Not all birth control methods are recommended right after giving birth, for example, you may have to wait at least three weeks before you can use the combined pill, the birth control patch, or the vaginal ring. 

While some forms of contraception may impact breastfeeding, Natural Cycles birth control is non-hormonal, non-invasive, and works from day one. The NC° app is an FDA Cleared medical device that has helped over three million registered users prevent and plan pregnancy naturally. The app's advanced algorithm uses your body temperature to determine your fertile window and confirm when you are ovulating. 

The timing of your first ovulation post-birth can vary widely among women and often depends on whether you are breastfeeding or not. You can get started with Natural Cycles at any point after pregnancy. However, until your period returns, the algorithm will only give you Red Days, meaning there is a chance you may be fertile, and you’ll therefore have to use protection or abstain from sex to prevent pregnancy. 

No matter where you are in your fertility journey, whether planning, preventing, or following pregnancy, the Natural Cycles app is packed with great info to help you learn more about your body. Why not find out if the first FDA Cleared birth control app could work for you?

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