Researchers studied whether folic acid supplements and folate-rich foods affect early birth in babies with spina bifida. Looking at data from over 1,200 pregnancies between 1999 and 2019, they found that babies were more likely to be born early when their mothers took no folic acid supplements AND ate very little folate-rich foods. However, taking supplements alone or eating enough folate-rich foods alone didn’t strongly increase early birth risk. The findings suggest that the combination of both low supplement use and low dietary folate might slightly increase the chance of premature birth in pregnancies affected by spina bifida.

The Quick Take

  • What they studied: Whether taking folic acid pills and eating folate-rich foods during pregnancy affects the timing of birth in babies born with spina bifida
  • Who participated: 1,199 babies with spina bifida born between 1999 and 2019, tracked through two large U.S. birth defect studies. About 18% of these babies were born early (before 37 weeks of pregnancy)
  • Key finding: Babies had a 73% higher risk of early birth when mothers took no folic acid supplements AND ate very little folate-rich food, compared to mothers who took supplements and ate adequate folate. Taking supplements alone or eating enough folate alone didn’t show strong effects
  • What it means for you: If you’re pregnant or planning pregnancy, especially with a family history of spina bifida, getting folic acid from both supplements and food sources appears important. However, this finding is modest and needs confirmation in future studies before making major changes to your routine

The Research Details

Researchers looked backward at medical records and pregnancy information from two large national studies that tracked birth defects from 1999 to 2019. They compared mothers of babies with spina bifida who took folic acid supplements versus those who didn’t, and looked at how much folate (a B vitamin) mothers ate from food sources. They used statistical methods to calculate the risk of early birth based on these different combinations of supplement use and food intake.

The study included information about when mothers took supplements (before pregnancy or during), how much folate they consumed from foods like leafy greens and fortified grains, and whether babies were born before 37 weeks of pregnancy (considered early). Researchers separated mothers into groups based on their folate intake levels to see if there were patterns in early birth rates.

This approach is valuable because it looks at real-world pregnancy data rather than just laboratory studies. By examining two different time periods and studies, researchers could see if findings were consistent. Understanding whether folate intake affects early birth in spina bifida pregnancies is important because early birth can cause serious health problems for newborns, and spina bifida pregnancies already carry extra risks

This study used large national databases with detailed pregnancy information, which is a strength. However, because researchers looked backward at existing records rather than following women forward during pregnancy, they couldn’t prove that low folate caused early birth—only that they appeared together. The study couldn’t account for all factors that might affect early birth, such as other health conditions or lifestyle factors. The number of babies in the highest-risk group (no supplements plus low folate) was relatively small, making the findings less certain

What the Results Show

Among 1,199 babies with spina bifida, 217 (about 18%) were born early. When researchers looked at folic acid supplements alone, mothers who didn’t take supplements had a slightly higher risk of early birth, but this difference wasn’t strong enough to be certain it was real (the confidence range included 1.0, meaning no effect).

When looking at dietary folate intake alone—how much folate mothers ate from foods—there were no clear patterns. Mothers eating the least folate had similar early birth rates as those eating more folate.

However, when researchers combined both factors, they found something more notable: mothers who took no supplements AND ate very little folate-rich food had a 73% higher risk of early birth compared to mothers who took supplements and ate adequate folate. This was the only combination that showed a clear association with early birth.

The researchers emphasized that while this finding is interesting, it’s modest in size and needs to be confirmed by future studies before drawing firm conclusions.

The study didn’t report major secondary findings. Researchers noted that the timing of when mothers started taking supplements (before pregnancy versus during pregnancy) could be important but wasn’t fully explored. They suggested future research should look more carefully at when during pregnancy folate intake matters most

Previous research has shown that folic acid supplements reduce the risk of spina bifida itself, which is why supplements are recommended for all women of childbearing age. This study adds new information by looking specifically at early birth risk in pregnancies already affected by spina bifida. The findings align with general knowledge that adequate folate is important for healthy pregnancy, though the specific connection to early birth in spina bifida cases hasn’t been well studied before

The study looked backward at existing records, so researchers couldn’t prove that low folate caused early birth—only that they occurred together. They couldn’t measure all factors that might affect early birth, such as maternal health conditions, stress, or other lifestyle factors. The group of mothers with both no supplements and low folate intake was relatively small, making the findings less certain. Different data collection methods between the two studies (1999-2011 versus 2014-2019) might have affected results. The study couldn’t determine the best timing for taking supplements or the exact amount of folate needed

The Bottom Line

Women planning pregnancy or currently pregnant should aim to get folic acid from both supplements (400 micrograms daily is standard) and folate-rich foods like leafy greens, legumes, and fortified grains. This recommendation has moderate confidence based on this study combined with existing evidence about folate’s importance in pregnancy. Women with a family history of spina bifida should discuss supplementation plans with their healthcare provider before pregnancy

This research is most relevant to women planning pregnancy, especially those with a family history of spina bifida or neural tube defects. Women already pregnant should discuss their folate intake with their healthcare provider. Healthcare providers caring for high-risk pregnancies should consider assessing both supplement use and dietary folate intake. This doesn’t change recommendations for the general population, which already emphasize folic acid supplementation

Folate’s effects on pregnancy develop throughout the pregnancy, with the most critical period being before pregnancy and early pregnancy. If you’re not currently taking supplements, starting them now won’t immediately change current pregnancy outcomes, but it’s important for future pregnancies. If you’re pregnant, discuss your current folate intake with your healthcare provider rather than making sudden changes

Want to Apply This Research?

  • Track daily folic acid supplement intake (yes/no) and log folate-rich foods consumed (servings of leafy greens, legumes, fortified grains, or other folate sources). Aim for at least one serving daily from folate-rich food sources plus consistent supplement use
  • If not already taking folic acid supplements, add a daily supplement to your routine at the same time each day (such as with breakfast). If you don’t eat folate-rich foods regularly, add one serving daily—examples include a spinach salad, bowl of fortified cereal, or serving of beans. Track both behaviors in the app to build consistent habits
  • Create a weekly check-in to review supplement adherence and folate food intake. Set reminders for daily supplement use. Use the app’s food logging feature to track folate-rich foods. If planning pregnancy, establish these habits 3 months before conception. During pregnancy, share your app data with your healthcare provider to discuss overall folate intake from all sources

This research describes associations found in a study of pregnancies affected by spina bifida and should not be interpreted as medical advice. The findings are modest and require confirmation through additional research. If you are pregnant, planning pregnancy, or have a family history of neural tube defects, consult with your healthcare provider about appropriate folic acid supplementation and dietary intake. Do not change your current supplement regimen based solely on this study. This information is educational and not a substitute for professional medical guidance.