What to Know About Breastfeeding While Pregnant

Medically Reviewed by Dany Paul Baby, MD on April 11, 2022
5 min read

Many believe that breastfeeding prevents pregnancy. However, women can still conceive while breastfeeding. In such cases, mothers can continue breastfeeding their older child during the new pregnancy

If you’re pregnant and breastfeed your older child, you may have questions about safety and risks. Here’s everything you need to know about breastfeeding while pregnant.

Most women don’t ovulate for six weeks after giving birth. Breastfeeding delays ovulation. Ovulation depends, however, on the frequency of breastfeeding. If you breastfeed frequently, you may only ovulate after many months or more than a year. This is considered a natural but temporary form of birth control. It is called the lactation amenorrhea method (LAM) of birth control. 

LAM is effective only if you breastfeed exclusively and frequently, though. The time between two feedings must be less than 4 hours in the day or 6 hours at night. 

Fortunately, this method is safe and has no side effects. It can be used for 6 months after giving birth or until your period returns.

If you stop breastfeeding, you may start ovulating within 3 weeks after giving birth. This can increase your likelihood of getting pregnant while breastfeeding. 

Breastfeeding and pregnancy can overlap. It usually happens if you breastfeed your older child over a long duration. As your older child becomes a toddler, you may choose to continue breastfeeding them. At that age, they can get their energy supply from other foods and still have breast milk for nutrition. When your breastfeeding frequency reduces, though, your chances of ovulation and conception increase.

Many believe that breastfeeding during pregnancy is harmful to the unborn baby. However, research shows that it's safe to breastfeed if your pregnancy is uncomplicated. Breastfeeding won’t affect you, your unborn baby, or your older child. 

Still, you must be sure to get enough healthy calories and drink plenty of fluids.

While breastfeeding, you may also have to consider some side effects, and your nursing child may notice some changes in the breast milk. 

Side effects of breastfeeding while pregnant include:

Uterine contractions. During breastfeeding, your body releases the hormone oxytocin. It stimulates breast milk production, but it also causes uterine contractions. These contractions are usually mild and aren't a concern for uncomplicated pregnancies. 

In a complicated or high-risk pregnancy, on the other hand, oxytocin can increase uterine movement and affect the pregnancy. Your doctor may ask you to avoid breastfeeding while pregnant if you’ve had a previous miscarriage or premature birth.

Changes in breast milk. Breast milk remains nutritional throughout pregnancy. However, its contents, quantity, consistency, and taste may change over time due to hormonal changes. Breast milk can become saltier, and its production may decrease as your pregnancy progresses. This can naturally make the older child wean on their own before your new baby is born.

Physical discomfort. In the early stage or first trimester of your pregnancy, you may have nipple tenderness and breast soreness. You may have a decreased food and water intake due to morning sickness and feel tired. Such physical discomfort may increase while breastfeeding.

Health risks. Lactation takes up energy on top of your pregnancy. The high physical and nutritional demand of frequent breastfeeding during pregnancy can present health risks for your unborn baby. They include:

If you have the following risks, your doctor will ask you to avoid breastfeeding while pregnant and wean your older child:

  • Painful symptoms in the first trimester
  • History of miscarriage or pregnancy loss 
  • Bleeding during a previous pregnancy
  • Previous premature delivery 
  • Preterm labor in your current pregnancy

Breastfeeding during pregnancy is a personal choice. If you choose to breastfeed while pregnant, here are some tips to help you and your child:

  • Take painkillers like Tylenol or use warm compresses on your breasts to ease breast soreness and nipple tenderness.
  • Ensure that you get enough rest if you feel tired due to pregnancy and breastfeeding your older child. 
  • Ask someone to help you with household chores or childcare. 
  • Avoid drinking coffee or energy drinks, as they can dehydrate you.
  • Have regular times for eating and drinking water throughout the day. This can reduce nausea and help you with your food and water intake to maintain your breast milk supply
  • Drink lots of water. Have sugar-free drink mixes that are safe for pregnancy. 
  • Make sure you have healthy food and get enough calories for the nutritional needs of your babies. 
  • Reposition your older child during breastfeeding. Make sure it’s comfortable for you. You can lie down and let your child lie on top or beside you while nursing. 

Tandem feeding. When the new baby arrives, you can continue breastfeeding your older child. This is called tandem feeding. You can feed both children in the same sitting. It helps save time and encourages bonding between the siblings. However, make sure you breastfeed your new baby before the older one. 

After the new baby is born, your breast milk will become thick and yellowish for some time. This provides nutrients and calories to your baby. Your older child can have this newborn milk, but it may cause diarrhea. 

Weaning. Weaning means getting your child used to having food other than breast milk. When you and your older child are ready, you can start weaning them. Your older child may stop having breast milk on their own before your new baby is born. This is because pregnancy can decrease milk production and make breast milk saltier. 

Although it is your choice to breastfeed during pregnancy, talk to your doctor or lactation consultant. They'll let you know whether it is safe for you to breastfeed during pregnancy. They will also help you with your diet, calorie intake, and how to wean your child off breastmilk.