Breastfeeding during pregnancy – what you need to know

If you just found out you’re pregnant but you’re still breastfeeding another child, you’re in the right place! Here’s what you need to know.

Whether you’re worried about the safety of breastfeeding while pregnant, or you just want to know what it’s like to nurse while pregnant, I can help. I have nursed through three pregnancies (although one of them weaned about halfway through). I love the connectedness of my children’s breastfeeding journeys that came from nursing them through pregnancy.

Table of Contents

Will breastfeeding while pregnant cause miscarriage?

There’s not a lot of research published in the scientific literature about nursing while pregnant. What there is, though, concludes that nursing while pregnant is safe for the developing fetus (assuming no complications).

UPDATE: A new study has shown that if you are exclusively breastfeeding with no complementary solids (as you would be if your child was under 6 months), there may be an increased risk of miscarriage. If your child is old enough for solids, there is no increased risk. With that said, consider supplementation with formula if you become pregnant before your child is 6 months old.

Studies have shown that “breastfeeding should be continued until natural weaning occurs” even if the mother is pregnant. In addition, these studies show that there’s no increased risk of miscarriage or of low birth weight for newborns of breastfeeding pregnant mothers.

In addition, there is plenty of anecdotal evidence that tandem nursing is safe. The thousands of mothers in support groups for tandem nursers is good evidence that it’s totally possible to nurse through pregnancy.

breastfeeding older toddler in his mother's arms

However, not all OBs are aware of this fact, and some are uncomfortable with the idea of a pregnant woman breastfeeding. In fact, the OB I had first chosen told me I “had to wean” by 14 weeks of pregnancy. I knew this simply wasn’t true, so I chose to change providers.

Don’t be afraid to find a provider who supports your parenting decisions. Obstetricians are often not trained in lactation research, so they likely aren’t up-to-date on the best information.

Can breastfeeding while pregnant cause early labor?

When people are concerned about nursing while pregnant, they’re often concerned that the oxytocin release could cause premature labor (or even miscarriage). Fortunately, our body has safeguards against that.

You may know that labor contractions are caused by oxytocin. But the thing is, this oxytocin has to bind to special receptor sites on the uterus to cause contractions. No receptors, no contractions.

While nursing does release oxytocin, (as does, ahem, other activities that pregnant people engage in during pregnancy), the uterus doesn’t have nearly the number of oxytocin receptors needed until 38 weeks of pregnancy. Therefore, that oxytocin has nowhere to go, and it does nothing to cause contractions.

While breastfeeding won’t make you go into labor early, it can make labor that has already started much more intense. For example, mothers desperate to see their new baby are told that nipple stimulation could get labor going. Well, breastfeeding is definitely a form of nipple stimulation.

When your body is ready, the number of oxytocin receptors on your uterus multiply by the hundreds, meaning the oxytocin can bind and start productive contractions.

Basically, as long as you haven’t been told to abstain from sex to avoid early labor, you should be okay to breastfeed.

What happens if you breastfeed during labor?

While breastfeeding won’t make labor start, it will certainly ramp up contractions and make your labor more intense (and perhaps quicker).

In my case, I woke up on morning, 39 weeks pregnant and in labor, with fairly minor contractions. The past several days, I have been nursing my daughter in the morning as long as I could stand it through Braxton-Hicks contractions.

But this morning, I nursed my oldest, the contractions were much stronger. I realized I was in labor. The next hour and a half was a blur. We got to the hospital about 45 minutes before my baby was born at about 9:15, less than three hours after I woke up in labor. I know that second labors are generally faster anyways, but the morning nursing session definitely sped up the process.

Big sister toddler meeting her newborn baby sister

It was so lovely to watch them meet. The first thing my oldest said was, “A baby!” She was also very concerned that her baby sister’s hat stayed on, as you can see in this picture.

UPDATE: I also nursed this second daughter through my third pregnancy. That time, I chose to keep her nursing sessions very short at the tail end of my pregnancy. While I appreciated how quickly my second labor and birth passed, I also wanted to have a less intense labor the third time around!

Pros and cons of breastfeeding while pregnant

If you’re committed to breastfeeding and you know all its benefits for your child, you may not want to wean. And that’s okay! Just make sure you consider all the pros and cons.

Pro: Provides antibodies and nutrients for your toddler

The benefits of nursing for your child don’t go away once you’re pregnant. You’ll still be providing antibodies and other health benefits to your little one (even as your supply dwindles somewhat to colostrum).

Pro: Keeps your toddler calmer

Honestly, there were times when breastfeeding made things easier for me as a pregnant mom. I was exhausted, and I didn’t have the energy to chase down my toddler at the end of the day. So instead, I would lure her into lying down and cuddling with me by offering the boob.

Pro: Helps you connect with your toddler

Those nursing cuddles are a nice way to bond. Plus, as your pregnancy progresses, you’ll likely get a chance to let your toddler feel the kicks and punches from your baby, letting them bond with their new sibling too.

Toddler girl kissing her mother's pregnant belly

Con: May make morning sickness worse

Of course, there are some downsides to nursing while pregnant too. For me, tandem nursing increased my first trimester morning sickness.

To combat morning sickness, make sure to stay hydrated and eat plenty of protein. Even if crackers seem easier to stomach, I found that I felt better if I had protein in me, like cold rotisserie chicken or a bagel with cream cheese.

I also found that night weaning (so that I was only breastfeeding during the day) helped me feel a little better. If you need to night wean, I tips for you below.

Want everything you need to night wean at your fingertips? Subscribe for the Night Weaning Action Pack, full of tips, what to expect the first few days of night weaning, and a progress tracker to keep you encouraged.

Con: May be sore while nursing

Your nipples may be extremely sensitive during pregnancy, especially during the first trimester. If that’s the case, it may be painful to nurse.

Con: May deal with nursing aversion

You may also experience nursing aversion with your toddler, a feeling of skin-crawling disgust at your child’s touch. Breastfeeding aversion and agitation can be very traumatic for moms, because on top of disliking nursing, you may have feelings of guilt or shame for reacting so strongly to your child.

In these cases, you may need to set some gentle limits with your nursing toddler. For example, you may choose to night wean (night weaning really helped my nausea in the first trimester of my second pregnancy). Or you may set limits, such as only nursing during certain times of the day.

Do you need help knowing how to set limits with your little boob monster without causing a massive melt down? Check out the FREE Gentle Breastfeeding Limits cheat sheet.

Just remember that breastfeeding is a two-way street, so if something isn’t working for you, you’re allowed to make changes. Even if you decide that you need to wean entirely, that’s okay.

Some toddlers are off-put by the salty taste of your changing milk, and they may self-wean (like my third did). Especially if you don’t go out of your way to offer, and gently distract your child when they do ask, it may be no problem to get them to forget all about nursing.

Other kids will keep nursing even if you’ve stopped producing at all. My two daughters were like this. Just follow your child’s lead.

Of course, your toddler will likely want to keep nursing after the new baby is born. And it’s totally possible! In fact, I tandem nursed twice.

While tandem nursing has its unique challenges, it’s also a really sweet way for your little ones to bond.

How people responded to me breastfeeding while pregnant

Finally, people may react oddly to you breastfeeding while pregnant. I have a funny story from when I was pregnant with my second child. While I didn’t go out of my way to publicize my choice to nurse while pregnant or to tandem nurse, there was one incident in Disney World when I was “caught.”

We were in the Magic Kingdom. I was six months pregnant with my second and already huge. My daughter was exhausted. She needed a nap, and I hoped that nursing her would help her go to sleep.

I took my little girl to one of the baby care centers that had a nice, quiet nursing room with cozy recliners. I hoped that the dark would lull her to sleep.

As I walked into the room that was labeled For nursing mothers only, a little old lady cast member asked, “Are you going to nurse her?” Puzzled, I told her yes, and she let me walk by. I walked in and curled up with my daughter in a rocking chair (naturally, she never fell asleep, but that’s another story).

A little later, it dawned on me why this woman singled me out to specifically ask if I was planning to nurse. She may had never seen a breastfeeding woman sporting a baby bump! I guess she thought I was just wanting to snag one of those cozy chairs for myself.

Conclusions on what you need to know about breastfeeding while pregnant

Generally speaking, there’s no reason for you to feel like you have to end your breastfeeding relationship with your older child as long as they’re over 6 months old and you haven’t been restricted from sexual activity (which stimulates oxytocin release just like nursing).

But remember, breastfeeding is a two-way street, especially when you have an older nursling. Make sure that whatever you choose is right for you and your child. Enjoy this special time before your toddler becomes a big brother or sister.

Samantha Radford has a PhD in Chemistry from Emory University (Atlanta, GA). She is an exposure scientist who focuses on maternal-child health. Samantha has years of research into learning about how chemical exposures affect both unborn babies and children, as well as how toxicants and medications are passed through breastmilk. Samantha also studies the effect of exposure to hormones induced by personal experiences, for example, cortisol in babies who are stressed or oxytocin in mothers bonding to their infants. Through the years, Samantha has expanded her academic and personal studies to how exposures to different parenting styles affect the mental and physical health of children as they grow to adulthood.

Evidence-based mommy