April 7, 2020

By Andrea Tran RN, BSN, MA, IBCLC

Some mothers plan to breastfeed through a pregnancy. Other breastfeeding moms get pregnant unexpectedly, before they have weaned, and decide that they don’t want to end their breastfeeding journey. All mothers want to do what is best and what is safe for them, the baby they are growing at their breast and the baby they are growing in their uterus.

Is it safe to breastfeed while pregnant?

Breastfeeding rates have increased over the years and mothers are breastfeeding for longer durations. One result of this is there are more mothers breastfeeding during pregnancy. This has provided more data regarding the safety and risks of breastfeeding for pregnant mothers. Overall the information is reassuring.

Much of the early research was conflicting regarding whether breastfeeding during pregnancy affected the risk of miscarriage. A systematic review of available research was published in 2017. It looked at 19 studies conducted over 25 years (1990-2015) and determined that breastfeeding during pregnancy does not increase the risk of miscarriage. It also did not find any impact on the birth weight of the new baby. Another study found no increased risk of premature birth or effect on birth weight.

The American College of Obstetricians and Gynecologists (ACOG) confirms that breastfeeding during pregnancy does not increase the risk of either miscarriage or preterm birth in women who are low risk. Women who have a history of preterm birth, miscarriage, or other risk factors should discuss their particular situation with their health care provider.

ACOG does mention that pregnant mothers who are breastfeeding have an increased risk of developing anemia. A health care provider may recommend an iron supplement and more frequent monitoring of blood count values.

Supporting the growth of a nursling and a fetus does require extra calories be consumed by a pregnant woman who continues breastfeeding.

Will my milk supply decrease when I get pregnant?

Breastfeeding moms will often experience a decrease in milk supply mid-pregnancy. This is due to the prolactin suppressing effects of increased levels of progesterone that occur during pregnancy. Increased stimulation from nursing more frequently or pumping will not increase the milk supply the way it does when breastfeeding moms are not pregnant.

A decrease in milk supply will occur earlier in some women. If a breastfeeding mom has an unexplained decrease in milk supply she should consider pregnancy as the cause. This is especially true if she is also experiencing nipple tenderness.

The age of the nursing baby will determine how much a decreased milk supply will impact the child’s calorie intake. Mothers should pay close attention to their baby’s weight gain to ensure they are getting adequate amounts of nutrition. If there is poor weight gain options include introducing or increasing complementary foods, offering breast milk that has been previously frozen, or offering formula.

Related: Low milk supply

Do pregnancy hormones get passed through the breastmilk?

While pregnancy hormones do appear in breast milk it is uncertain how they can affect a breastfeeding baby. It is known that the composition of breast milk changes during pregnancy, resembling milk when a woman is weaning. As a woman gets closer to her due date the milk will become more like colostrum. These changes will result in taste changes in a woman’s milk. The alterations in taste combined with a decreased milk supply may result in a child self-weaning. Due to the fact that children breastfeed for more than just nutrition some children will happily continue to breastfeed.

How do I deal with nipple soreness when breastfeeding during pregnancy?

Pregnant mothers often experience nipple tenderness when they breastfeed during pregnancy. They may experience this in early pregnancy or it may last throughout the pregnancy. For some women, sore nipples is the first clue that they could be pregnant. In part, the challenge is that when babies get older they may not maintain that picture-perfect latch that is encouraged in the early weeks of nursing. If a baby is not actively sucking and has a poor latch a mother can end the feeding. Gel pads provide comfort for tender nipples.

Many mothers successfully breastfeed through a pregnancy and go on to tandem nurse both babies. In most cases, it is safe for everyone.

Sources
Breastfeeding During Pregnancy: A Systematic Review
Journal of Nursing Research - A Comparative Study of Breastfeeding During Pregnancy: Impact on Maternal and Newborn Outcomes
ACOG - Optimizing Support for Breastfeeding As Part of Obstetric Practice

Andrea Tran RN, BSN, MA, IBCLC is a freelance writer who has been helping moms and babies breastfeed for over twenty-five years. She is married and the mother of three adult children.