Researchers followed over 3,200 pregnant women to see if taking folic acid vitamins at different times during pregnancy affected how babies’ brains and bodies developed. They checked babies at 6 months and 18 months old. The study found that women who took the recommended dose of folic acid before and early in pregnancy had babies with fewer communication delays at 18 months. Women who kept taking folic acid through the second and third trimesters had babies with better fine motor skills and problem-solving abilities at 6 months. These findings suggest that folic acid supplementation throughout pregnancy may support healthy brain development in babies.
The Quick Take
- What they studied: Whether taking folic acid vitamins at different times during pregnancy helps babies develop better brain and motor skills
- Who participated: 3,246 pregnant women and their babies. About 2,905 babies were tested at 6 months old and 3,005 babies at 18 months old to measure how their brains and bodies were developing
- Key finding: Babies whose mothers took the recommended folic acid dose (0.4 mg daily) before and early in pregnancy had about 52% fewer communication problems at 18 months. Babies whose mothers continued folic acid through months 4-9 of pregnancy had much better fine motor skills and problem-solving abilities at 6 months
- What it means for you: If you’re planning to get pregnant or are pregnant, taking folic acid as recommended by your doctor appears to support your baby’s brain development. However, this is one study, so talk to your healthcare provider about what’s right for you
The Research Details
This was a prospective birth cohort study, which means researchers followed pregnant women from the start and tracked their babies’ development over time. The researchers collected information about what vitamins and supplements the mothers took at different stages of pregnancy—before pregnancy, early pregnancy, and during the second and third trimesters (months 4-9). They then tested the babies’ development at 6 months and 18 months using standardized tests that measure things like motor skills, communication, and problem-solving. The researchers used advanced statistical methods to account for other factors that might affect baby development, like the mother’s age, education, and overall health.
Following mothers and babies over time (rather than just looking backward) gives stronger evidence about cause and effect. By measuring babies at two different ages, the researchers could see if folic acid’s effects showed up early or later in development. Using statistical adjustments helped ensure that the results weren’t just due to differences between mothers who took folic acid and those who didn’t
This study involved a large number of participants (over 3,200), which makes the findings more reliable. The researchers used rigorous statistical methods including propensity score analysis to account for confounding factors. However, the study was observational, meaning mothers chose whether to take folic acid rather than being randomly assigned, so we can’t be completely certain folic acid caused the improvements. The study was published in a reputable peer-reviewed journal, which means other experts reviewed the work
What the Results Show
The study found two main benefits of folic acid supplementation. First, mothers who took the standard recommended dose of folic acid (0.4 mg per day) before pregnancy and in early pregnancy had babies with significantly fewer communication delays at 18 months. Specifically, these babies had about half the risk of communication problems compared to babies whose mothers didn’t take folic acid. Second, mothers who continued taking folic acid through the second and third trimesters (after 12 weeks of pregnancy) had babies with much better fine motor skills—like grasping and coordinating hand movements—at 6 months. These same babies also showed better problem-solving abilities. The improvements were substantial: babies whose mothers continued folic acid had about 69-80% lower risk of delays in these areas.
The study measured several areas of baby development including gross motor skills (like rolling over and sitting), fine motor skills (like grasping), communication, and problem-solving. While the main findings focused on communication and fine motor skills, the researchers tracked all these areas to get a complete picture of development. The fact that benefits appeared at different ages (6 months and 18 months) suggests that folic acid may support development at different stages
It’s long been known that folic acid prevents serious birth defects of the brain and spine (neural tube defects). This study goes further by suggesting that folic acid may also support normal brain development even when there are no birth defects. The finding that continued folic acid through later pregnancy may be beneficial is newer—most previous research focused on early pregnancy. This aligns with the idea that the brain continues developing throughout pregnancy and after birth
The study was observational, meaning mothers chose whether to take folic acid rather than being randomly assigned to take it or not. This means we can’t be 100% certain that folic acid caused the improvements—other factors about mothers who chose to take supplements might explain the results. The study didn’t measure actual folate levels in mothers’ blood, so we don’t know if all mothers who reported taking folic acid actually had adequate levels. The study was done in one country, so results might differ in other populations. Finally, while the sample size was large, the number of babies with developmental delays was relatively small, which makes some of the findings less certain
The Bottom Line
If you are planning pregnancy or are pregnant, discuss folic acid supplementation with your healthcare provider. The standard recommendation is 0.4 mg (400 micrograms) daily starting before pregnancy and continuing through at least the first trimester. This study suggests continuing through the entire pregnancy may provide additional benefits. This is a moderate-confidence recommendation based on one observational study; stronger evidence would come from randomized controlled trials
Women planning to become pregnant or who are currently pregnant should pay attention to this research. Women with a family history of neural tube defects or those taking certain medications should especially discuss folic acid with their doctor. This research is less directly relevant to women who are not planning pregnancy, though adequate folate is important for everyone’s health. Men should note that paternal nutrition also matters for baby health, though this study focused on mothers
Benefits of folic acid supplementation appear to develop gradually. This study found effects on baby development measurable at 6 months and 18 months. It’s important to start folic acid before pregnancy if possible, as the critical period for preventing birth defects is very early in pregnancy, often before a woman knows she’s pregnant. Continuing through the entire pregnancy appears to support ongoing brain development
Want to Apply This Research?
- Track daily folic acid supplementation with a simple yes/no checklist. Users can log whether they took their folic acid supplement each day and note the dose (in micrograms or mg). This creates a visual record of consistency and helps ensure the recommended daily intake
- Set a daily reminder at the same time each day (like with breakfast) to take folic acid. Users can link this to an existing habit to make it easier to remember. The app could provide educational notifications about why folic acid matters at different pregnancy stages
- Track folic acid intake throughout the entire pregnancy journey. Users can set goals for consistency (like 95% adherence) and review monthly summaries. The app could also track baby developmental milestones to help users see the connection between prenatal nutrition and infant development over time
This research suggests an association between folic acid supplementation and infant development, but does not prove that folic acid causes these improvements. This information is for educational purposes only and should not replace advice from your healthcare provider. All pregnant women or those planning pregnancy should consult with their doctor or midwife about appropriate supplementation for their individual situation. Do not start, stop, or change any supplements without medical guidance. If you have concerns about your baby’s development, contact your pediatrician immediately