What the Evidence Shows
A 2011 review of studies with more than 96,000 pregnant women, found that “taking any vitamin supplements prior to pregnancy or in early pregnancy does not prevent women from experiencing miscarriage or stillbirth.” In 2016, a follow-up to the 2011 review looked at studies of 276,820 pregnant women. Data showed that supplementation with various combinations of vitamins and minerals did not have any effect on the risk of miscarriage. However, supplementation with a multivitamin containing folate and iron did appear to decrease the risk of stillbirth (pregnancy loss after 20 weeks) compared to supplementation with folate and iron alone. Interestingly, multiple studies have shown that people who begin taking folate supplements before pregnancy experience fewer spontaneous abortions (another term for miscarriage). There is evidence from another 2016 study that women who took daily prenatal vitamins experienced a 55% overall lower rate of miscarriage compared to the participants who did not. Additionally, fewer women in the study who consistently took vitamins throughout early pregnancy experienced pregnancy loss than the people who did not take vitamins during the same gestational period. The study did point out that it did not track specific multivitamins consumed by participants. Therefore, researchers would need more information about particular vitamin contents to better understand their potential connection to miscarriage prevention. A contradictory 2014 study found an increased risk of miscarriage in women who took multivitamins, although the authors cautioned that more research was needed before making any recommendations. Despite the lack of definitive answers regarding the relationship between prenatal vitamins and the risk of pregnancy loss, what is known is that taking prenatal vitamins during pregnancy is very important for other reasons.
How Prenatal Vitamins Can Help During Pregnancy
Research is inconclusive on the connection between prenatal vitamins and miscarriage risk, but taking them is still a good choice for your baby’s development and your health during your pregnancy. Pregnancy comes with its own nutritional demands. Not only does your baby need high levels of nutrients to grow and develop, but your body is also doing quite a lot of work to support that growth. Specifically formulated for the nutritional needs of pregnant people, prenatal vitamins contain higher levels of certain nutrients like iron, folate, and calcium compared to regular multivitamins and can help fill in the gaps of an otherwise healthy diet during pregnancy. One 2016 study noted that people who maintain a poor diet during pregnancy are at risk of becoming deficient in iron, folate, vitamin D, and calcium, which can lead to health problems for both the pregnant person and baby.
The Special Role of Folate
Folate (vitamin B9) is a critical nutrient in the development of the neural tube, which goes on to form the baby’s spinal cord, spine, brain, and skull. If adequate amounts of folate are not present during neural tube development, there is an increased risk of spina bifida and anencephaly. Because the neural tube completes its development by about 28 days after conception—before some people even know they’re pregnant—ensuring an adequate intake of folate prior to getting pregnant is important. The National Institutes of Health (NIH) notes that folate deficiency in pregnant people can lead to:
Low infant birth weight Preterm delivery Intrauterine growth restriction (IUGR)
Doctors recommend that people start taking folate supplements (400–600 micrograms daily) at least one month before they begin trying to conceive.
What to Look for in a Prenatal Vitamin
According to the Cleveland Clinic, people who are pregnant or trying to get pregnant should look for a prenatal vitamin that contains the following key nutrients:
CalciumDHAFolate or folic acidIronVitamin B6Vitamin D
Your healthcare provider may also prescribe a prenatal vitamin that is tailored to your individual health needs so be sure to consult with them before deciding on what to add to your diet.
Known Miscarriage Risks
Research on prenatal vitamins and miscarriage is still evolving, but there are certain factors that are known to increase miscarriage risk, including:
Smoking Alcohol Caffeine (in excess) Obesity
Talk with your provider if you have concerns about any of these factors.
A Word From Verywell
Miscarriage can be caused by a variety of factors, many of which are out of your control. Still, taking prenatal vitamins, getting good prenatal medical care, and taking care of yourself are the best ways to help support a healthy pregnancy. Talk to your healthcare provider if you are unsure of what to do during your pregnancy or feel worried about the health of your baby.
