How long should you wait before getting pregnant again?

For most women, it’s best to wait at least 18 months between giving birth and getting pregnant again. This means your baby will be at least 1½ years old before you get pregnant with another baby. This gives your body time to fully recover from your last pregnancy. If you have health conditions or risks or other needs that raise questions with this approach, talk with your health care provider.

Why is 18 months important?

Getting pregnant again before 18 months increases the risk for certain health problems for your baby, including:

» Premature birth. This means your baby is born before 37 weeks of pregnancy. The shorter the time between pregnancies, the higher your risk for premature birth.

» Low birthweight. This is when your baby is born weighing less than 5 pounds, 8 ounces.

» Being small for gestational age. This means your baby is smaller than normal based on the number of weeks in the womb.

Babies with these health conditions are more likely to have serious long-term health problems, or even die before their first birthday, than babies without the conditions.

What can you do to help get that 18 months?

» Use effective birth control (contraception or family planning) until you’re ready to get pregnant again. Birth control helps keep you from getting pregnant. Examples include intrauterine devices (IUDs), implants, the pill and condoms. Other than abstinence (not having sex), IUDs and implants are the most effective kinds of birth control. They work well at preventing pregnancy because they’re low maintenance. Once you get them from your provider, they work for a long time (up to several years), and you don’t have to worry about getting pregnant until you have it removed.

» If you’re pregnant, talk to your provider before you give birth about getting an IUD or implant right after you have your baby. If you don’t get an IUD or implant right after giving birth, talk with your provider about getting one at your postpartum checkup, which is typically about 6 weeks after you have your baby.

» If you’re older than 35 or have had a miscarriage or stillbirth, talk with your provider about how long to wait between pregnancies. Waiting 18 months might not be right for you.

Why does getting pregnant again too soon increase the chances for premature birth?

Experts don’t know for sure why getting pregnant again too soon increases your chances of premature birth and other health problems for your baby. It may be because your body needs time to:

» Build up its supply of nutrients, like folic acid. Nutrients, like vitamins and minerals, help your body stay healthy. If your body doesn’t have enough nutrients and you get pregnant again too soon, it may cause health problems for you or your baby. During pregnancy and breastfeeding, your baby gets the nutrients she needs from your body. After having a baby, your body may not have enough of certain nutrients, like folic acid. Folic acid is a vitamin that every cell in your body needs for normal growth and development. If you take it before you get pregnant, it can help reduce your baby’s chances of having birth defects of the brain and spine called neural tube defects (also called NTDs). If you get pregnant again too soon and your folic acid levels are low, your next baby is more likely to be born prematurely, with low birthweight or with NTDs.

» Heal from infection and inflammation. Infection during pregnancy can lead to inflammation (redness and swelling) in parts of your body, like the uterus. If you have a condition like endometritis (inflammation of the lining of the uterus) during pregnancy and get pregnant again before your body has fully healed, you may have the condition again in your next pregnancy. Inflammation may play a role in preterm premature rupture of membranes (also called PPROM), which is when the sac around the baby breaks before 37 weeks pregnancy, causing premature labor and birth.

» Reset the microbiome of the vagina. The microbiome is a group of microorganisms, like bacteria, living things so small you need a microscope to see them. Some experts think the microbiome in a woman’s vagina may play a role in premature birth. For example, having an infection called bacterial vaginosis affects the vaginal microbiome and can increase your chances of having a premature baby. Also, the vaginal microbiome of women who have had a premature baby may be different than that of women who have a baby after 37 weeks of pregnancy. And it may take time — even a year — for the vaginal microbiome to go back to how it was before pregnancy. The March of Dimes supports research to learn more about the vaginal microbiome and premature birth.

March of Dimes leads the fight for the health of all moms and babies. We support research, lead programs and provide education and advocacy so that every baby can have the best possible start. Visit marchofdimes.org or nacersano.org for more information. Visit shareyourstory.org for comfort and support. Find us on Facebook and follow us on Instagram and Twitter.

Dr. Lisa Waddell is the senior vice president and deputy medical officer for the March of Dimes.