Is It Safe to Breastfeed During Pregnancy?

I had a positive pregnancy test when my first daughter was just 9 months old, and I immediately called my OB-GYN to share the news.

"Stop breastfeeding," she told me, and dutifully, I weaned my daughter that night.

A week later, when I miscarried what turned out to have been a chemical pregnancy, I had two things to mourn: the baby I'd expected, and the nursing relationship I'd ended with my daughter.

I wondered, even if the pregnancy had continued, was it necessary to wean her? Why would my OB-GYN have said that?

What I've learned since that day has changed my mind entirely about nursing during pregnancy. In fact, if I am lucky enough to get pregnant while breastfeeding, I'd want to continue the nursing relationship, even extending into a "tandem nursing" situation after the baby is born.

Pain and Milk Supply Issues

In all my years of playing with my young children in parks, I have never once seen an obviously pregnant person breastfeeding. Why not?

Many times, apparently, it's very painful.

According to Wendy Haldeman, one of the founders of the Los Angeles–based The Pump Station, it can hurt to breastfeed during the first trimester. "The nipple soreness is just something the mother has to endure," she told me. "Some can; others find it is just too painful to continue."

Local mothers who attempted nursing while pregnant agreed with Haldeman. "By the time I was about two months pregnant, nursing became excruciatingly painful," Amanda, a local mom, shared. "I almost cried every time I went to nurse, it hurt so bad. I ended up weaning my son at that point."

Milk supply can also diminish. "My experience is that if the first baby is over a year, the milk supply is not as much of a concern," said Haldeman. "Infants under 9 months of age frequently need to be supplemented with formula because the mother simply can't produce enough milk."

Basically, your body begins producing a different quantity and quality of milk sometime in the second trimester. This is spelled out in "Breastfeeding for Dummies" by Sharon Perkins, RN, and Carol Vannais, RN: "Somewhere between four and eight months of pregnancy, your milk does start changing from mature milk back to colostrum, the first type of milk that you gave your baby. The colostrum usually tastes a little different than mature milk, so you may find your baby not as interested in this new menu item and starting the process of weaning."

Is Breastfeeding While Pregnant Safe?

If I could bear the pain and my baby could bear the "new menu item," is it a good idea from a medical perspective to continue breastfeeding while pregnant?

"In most circumstances, breastfeeding can be continued during an uncomplicated pregnancy," Pamela Berens, MD, an associate professor of obstetrics, gynecology, and reproductive sciences at the University of Texas Health Science Center, at Houston, who researches lactation and breast milk, told Health.

However, Dr. Berens explained that if your healthcare provider has instructed you not to have intercourse, then you may also want to reconsider breastfeeding.

Both orgasm and breastfeeding trigger a release of oxytocin, which some people may want to avoid, as it can cause uterine contractions. "The increased oxytocin could be problematic in the patient that is experiencing preterm labor," said Dr. Berens.

Dr. Berens advised that pregnant individuals with a history of preterm labor, placenta previa, or a "classical" C-section uterine incision consider weaning. However, these reasons occur later in pregnancy, so the parent wouldn't need to wean abruptly in their first trimester.

Dr. Berens recommended that people with severe hypertension (high blood pressure), severe vascular or renal disease, or a prior "growth-restricted" infant (a cautionary recommendation based on what Dr. Berens described as a "small body of research that suggests that the weight of the infant born to the mother that breastfed during her pregnancy may be very slightly reduced") wean as well.

Could Nursing Cause a Miscarriage?

Though no research has found any increased risk of miscarriage in people who continue breastfeeding during pregnancy, they might want to consider weaning if they are experiencing bleeding during early pregnancy, said Dr. Berens.

But be sure to confirm the pregnancy is viable. "If the pregnancy has already miscarried or is 'non-viable' (meaning no fetus has formed or the fetus has no heartbeat), then there is no benefit to weaning," said Dr. Berens.

If only I'd heard that sound advice four years ago! Armed with this knowledge, I know that for any future pregnancies, I'll hold on to my nursing relationship with much more confidence.