Can You Get Pregnant While Breastfeeding? The LAM Method Explained

The Quick Answer

Yes, you can get pregnant while breastfeeding. Breastfeeding suppresses ovulation — but it doesn't eliminate it. How much it suppresses depends entirely on your nursing pattern, your baby's age, and your individual hormonal response.

For some women, fertility returns within weeks of delivery despite exclusive breastfeeding. For others, ovulation stays suppressed for over a year. The unpredictability is the reason breastfeeding alone isn't considered reliable birth control — unless you follow the specific rules of the Lactational Amenorrhea Method (LAM).

How Breastfeeding Suppresses Fertility

The mechanism is straightforward: when your baby suckles, your body produces prolactin. Prolactin is the hormone that drives milk production — but it also suppresses gonadotropin-releasing hormone (GnRH), which is the signal your brain sends to trigger ovulation. High prolactin essentially puts your reproductive system on pause.

The catch is that prolactin levels are closely tied to nursing frequency and intensity. Every time you skip a feeding, introduce a bottle, or your baby sleeps through the night, prolactin drops. Once it drops below a certain threshold, GnRH resumes, FSH and LH start rising, and ovulation can occur — often before your first postpartum period.

The Lactational Amenorrhea Method (LAM)

LAM is a formal contraceptive method recognized by the WHO, ACOG, and the Cochrane Collaboration. When practiced correctly, it's 98–99.5% effective at preventing pregnancy during the first 6 months postpartum — comparable to hormonal birth control.

But the rules are strict. All three conditions must be met simultaneously:

When Does Fertility Return During Breastfeeding?

The timing varies enormously between individuals. Here's what the research shows:

• Exclusive breastfeeding, no supplements: Average return of ovulation is 6–8 months postpartum. Some women don't ovulate until they wean entirely.
• Mixed feeding (breast + formula/solids): Average return is 3–6 months postpartum. Introducing solids at 6 months typically triggers fertility return within 1–3 months.
• Primarily formula feeding: Ovulation can return as early as 3–4 weeks postpartum. If you're not breastfeeding at all, fertility is essentially unaffected.
• Night weaning: Dropping nighttime feeds is one of the strongest triggers for ovulation return. The long overnight gap allows prolactin to fall significantly.

If You're Trying to Conceive While Breastfeeding

Many parents want to conceive baby #2 while still nursing baby #1. This is entirely possible, but you may need to make some adjustments to encourage ovulation.

If You're Trying NOT to Get Pregnant While Breastfeeding

Relying on breastfeeding alone as contraception is a gamble unless you're strictly following LAM criteria — and even then, only for the first 6 months. If an unplanned pregnancy would be a problem, use a backup method.

Breastfeeding-Compatible Contraception

ACOG considers the following methods safe during breastfeeding:

• Progestin-only options: The "mini pill," hormonal IUD (Mirena, Liletta, Kyleena), Depo-Provera shot, and Nexplanon implant are all safe for nursing mothers and don't affect milk supply in the vast majority of women.
• Copper IUD (Paragard): Hormone-free, effective for up to 10 years, and has zero impact on breastfeeding.
• Barrier methods: Condoms, diaphragms, and the cervical cap are always compatible.
• Combined hormonal methods (estrogen + progestin): The pill, patch, and ring containing estrogen may reduce milk supply, especially if started before 6 weeks postpartum. Most providers recommend waiting until 6 months or until breastfeeding is well established.

Breastfeeding During a New Pregnancy

If you do conceive while breastfeeding, you may wonder whether it's safe to continue nursing. For most healthy pregnancies, the answer is yes. ACOG and the Academy of Breastfeeding Medicine both state that breastfeeding during pregnancy is generally safe. Nipple stimulation does release oxytocin, which causes uterine contractions — but in a healthy pregnancy, these low-level contractions aren't strong enough to trigger preterm labor.

However, your milk supply will likely decrease during pregnancy (especially in the second trimester), and some toddlers self-wean due to taste changes. If you continue nursing through delivery, you'll be tandem nursing — feeding both a newborn and an older child — which is logistically demanding but biologically fine.

Discuss your plans with your provider. They may recommend weaning if you have a history of preterm labor, cervical insufficiency, or are carrying multiples.

The Bottom Line

Breastfeeding doesn't make you infertile — it makes you less fertile, temporarily, and the degree depends on how often and how intensively you nurse. If you're relying on it as contraception, follow LAM rules and know its limits. If you're trying to conceive, gradual reduction in nursing frequency (especially night feeds) is usually enough to bring ovulation back without fully weaning.

Either way, the best move is to start tracking. An OPK kit will tell you whether you're ovulating. A BBT thermometer will confirm it. And a pregnancy test will settle the question for good.