For many expecting parents who are currently breastfeeding, a common question arises: can continuing to breastfeed during pregnancy lead to a miscarriage? This concern is understandable, given the physiological changes occurring in the body. For most healthy pregnancies, however, continued breastfeeding is generally considered safe and does not increase the risk of miscarriage. This is a widespread concern, but the underlying mechanisms are often misunderstood.
How Breastfeeding Affects the Body During Pregnancy
Breastfeeding involves a fascinating hormonal process. When a baby suckles at the breast, it stimulates the release of oxytocin, often called the “love hormone.” This hormone is responsible for the milk ejection reflex, or “let-down,” which causes milk to flow. Oxytocin also plays a role in uterine contractions. These contractions are typically mild and localized, different from the strong, coordinated contractions of labor. The uterus is usually less sensitive to oxytocin during early pregnancy because the number of oxytocin receptor sites on uterine cells is sparse until much later in gestation, around 38 weeks. This natural protective mechanism helps prevent premature labor.
What the Research Shows
Medical studies and leading health organizations generally conclude that breastfeeding during an uncomplicated pregnancy does not increase the risk of miscarriage or preterm labor. The contractions caused by oxytocin release during breastfeeding are usually not strong or frequent enough to disrupt a healthy pregnancy. Organizations such as the American College of Obstetricians and Gynecologists (ACOG) and the World Health Organization (WHO) support breastfeeding and acknowledge that contraindications are few. While one study suggested a heightened risk of miscarriage with exclusive breastfeeding during pregnancy, especially in the first five months, it also noted no increased risk with complementary breastfeeding and highlighted limitations in the data. The broader scientific consensus indicates that the amount of oxytocin released during breastfeeding is typically insufficient to induce labor in a healthy pregnancy.
Circumstances Requiring Medical Consultation
While generally safe, specific situations warrant medical consultation regarding continued breastfeeding during pregnancy, such as a history of preterm labor or previous miscarriages. Other concerning signs include vaginal bleeding, uterine pain, or cramping. Multiple gestation, such as carrying twins or triplets, also warrants medical advice. Conditions like placenta previa, where the placenta covers the cervix, also require discussion with a doctor. These situations are exceptions, and medical guidance is important for the health of both the pregnant person and the developing fetus.
Guidance for Breastfeeding While Pregnant
For those continuing to breastfeed during a healthy pregnancy, practical considerations can help manage the experience. Nipple tenderness is a common side effect due to hormonal changes, which can sometimes be relieved by adjusting latch or position. Milk supply often decreases around the fourth or fifth month of pregnancy due to hormonal shifts, and the milk’s taste may change, potentially leading the older child to self-wean. Ensuring adequate hydration and nutrition is important, as the body requires additional calories for both pregnancy and milk production. Listening to one’s body and prioritizing rest can help manage fatigue. Tandem nursing, breastfeeding both the newborn and older child after birth, is also a possibility.