Breastfeeding during pregnancy

Breastfeeding during pregnancy
You can continue to breastfeed during a new pregnancy. The following article sheds light on the subject.

Some mothers who choose to breastfeed for several months or years will become pregnant with their second baby while still nursing their first. She may then decide to continue breastfeeding because she feels that her baby still needs these moments of bonding and isn’t ready to be weaned.

Although some people worry about the safety of breastfeeding during pregnancy, the practice does not pose a health risk to the mother, unborn baby, or breastfed child.

What are the effects of breastfeeding during pregnancy?

The effects of breastfeeding during pregnancy have not been sufficiently studied. However, the limited available data suggest that there is little risk associated with breastfeeding during pregnancy if the mother is healthy, has a normal pregnancy, and has not had a high-risk pregnancy in the past.

Here are some common concerns related to breastfeeding during pregnancy.

  • Miscarriage and preterm birth
    During breastfeeding, a hormone called oxytocin is released. As oxytocin is responsible for contractions during childbirth, some mothers are concerned that breastfeeding during pregnancy may trigger a miscarriage or preterm birth. However, oxytocin is not produced in sufficient quantities during feedings to induce labour. Furthermore, pregnancy hormones block the effect of oxytocin. The uterus won’t react to oxytocin until the mother is at term. Finally, contractions also occur during sexual intercourse and are therefore not dangerous during a normal pregnancy.
    A few small studies have concluded that breastfeeding women are not more likely to miscarry or give birth prematurely. However, these studies were conducted among women whose pregnancies were normal. Women who are at risk of giving birth before their due date should therefore discuss their situation with their doctor before deciding whether to continue breastfeeding.
  • Fetal development
    Producing milk takes a lot of energy. In theory, breastfeeding during pregnancy could limit the resources available to the fetus. But if the mother is eating well, most experts agree that the baby’s growth is unlikely to be compromised. Studies on the subject have concluded that breastfeeding has little or no effect on the birth weight of the new baby.
  • Maternal health
    Breastfeeding during pregnancy takes a toll on the woman’s body. One study noted that some women who breastfeed during pregnancy have lower hemoglobin levels, which increases the risk of anemia. It’s one of the reasons why pregnant women are encouraged to take a prenatal multivitamin that contains folic acid and iron.
    However, a pregnant woman will be able to meet her nutritional needs if she’s well nourished. That’s why it’s important for women who are breastfeeding during pregnancy to follow a varied and balanced diet that’s rich in iron, vitamins, proteins, and minerals, while also staying well hydrated.
What are the chances of becoming pregnant while breastfeeding?
Breastfeeding greatly reduces the chances of conceiving, especially if all the following conditions are met:
  • Menstruation has not started again and no bleeding has been observed.
  • The baby breastfeeds at least every four hours during the day and every six hours at night. Breastfeeding takes place without following a schedule and without limiting the duration of feedings.
  • The baby is exclusively breastfed, i.e., they don’t consume any commercial formulas, food, or water.
  • The baby is under 6 months old.
As soon as one of these conditions is not met, however, breastfeeding can no longer be considered an effective means of contraception.

Does pregnancy affect breast milk?

Certain hormones are present during pregnancy that conflict with milk production. If you’re breastfeeding while pregnant, you may notice a drop in production in the first half of your pregnancy, especially during the second trimester.

Download this chart to keep track of how often your baby feeds, their bowel movements, and their urine output.

If your baby has started to eat solid food, this decrease is less of an issue, as breast milk is no longer their only source of nutrients. However, if your baby is under 6 months old and is still being breastfed exclusively, the amount of milk you’re producing may become insufficient. If this happens, consider meeting with a lactation consultant to determine if your milk production can be increased. Otherwise, your baby may need a supplement, such as maternal milk that was frozen before the beginning of the new pregnancy. If you don’t have enough breast milk, you can use commercial infant formula.

Hormonal changes during pregnancy can also change the breast milk’s composition. For example, in the first two months of pregnancy, the amount of protein, sodium, and chloride increases, while the amount of potassium, lactose, and glucose decreases. This can cause the breast milk to taste salty. The changes in breast milk composition won’t affect the child’s development.

However, some babies may dislike the change in taste, causing them to lose interest in breastfeeding. A survey of women who were breastfeeding during pregnancy revealed that, in 69 percent of cases, weaning took place during the second trimester.

When the new baby is born
After delivery, it’s possible to continue breastfeeding your child while breastfeeding your new baby. This is called tandem breastfeeding.

In the first few days after giving birth, your breasts will produce the colostrum your newborn needs. As the quantity of this milk is limited, it may be necessary to give your new baby priority. Afterward, when your milk comes in, various arrangements are possible depending on the age and needs of your older child.

Discomfort related to breastfeeding during pregnancy

About 75 percent of women who breastfeed during pregnancy report that their nipples are more sensitive. The discomfort is due to ongoing hormonal changes. Unfortunately, most of the recommended treatments for sore nipples are usually not very effective during pregnancy. To reduce unpleasant sensations, some mothers use breathing techniques. It’s also important to make sure your baby latches on properly. An evaluation by a lactation consultant may be required.

Use this guide to learn about breastfeeding positions and latching.

In addition, some mothers report feeling emotional distress when breastfeeding during pregnancy, which some describe as annoyance or irritability. To manage this type of discomfort, try distracting yourself during feeding times by reading or listening to music, for example. Breathing techniques are also a good option.

Finally, toward the end of pregnancy, your growing belly may make breastfeeding more difficult. If this happens, try lying down while breastfeeding. If your child is old enough, you may also ask them to help you find a comfortable position.

If a mother is unable to breastfeed comfortably during pregnancy, she may choose to wean her baby. The “don’t offer, don’t refuse” method and the use of distractions are effective strategies for gradually weaning an older child. By giving your child lots of affection and attention, you can easily meet their needs without breastfeeding.

Things to keep in mind

  • Unless contraindicated, breastfeeding during pregnancy doesn’t pose any risks to the unborn baby, the breastfed baby, or the mother.
  • The mother’s milk production may decrease in the first half of pregnancy.
  • Some pregnant women experience minor discomforts during feedings, but there are strategies that can help.


Naître et grandir

Scientific review: Louise Godin, graduate nurse and lactation consultant, IBCLC
Research and copywriting: The Naître et grandir team
Updated: October 2020



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