Researchers discovered that babies with growth problems in the womb have unusual chemical patterns in the fluid surrounding them. When they gave folic acid (a B vitamin) to pregnant animals with this condition, the babies grew better and their placentas (the organ that feeds the baby) worked more efficiently. The study suggests folic acid works by changing how genes are turned on and off in the placenta, potentially helping fix the structural problems that slow fetal growth. This finding could lead to new ways to help babies develop normally when growth problems are detected during pregnancy.

The Quick Take

  • What they studied: Whether folic acid could help fix growth problems in babies developing in the womb by changing how placental genes work
  • Who participated: The study used animal models (not human subjects) to test how folic acid affects babies with restricted growth and their placentas
  • Key finding: Folic acid supplementation significantly improved fetal growth measurements and helped restore normal placental structure, with the placenta becoming more efficient at supporting the baby
  • What it means for you: This research suggests folic acid may be helpful for pregnancies with growth concerns, but human studies are needed before doctors can recommend it as a treatment. Pregnant people should continue taking prenatal vitamins with folic acid as recommended by their healthcare provider

The Research Details

This was a laboratory research study using animal models to understand how folic acid affects fetal growth restriction—a condition where babies don’t grow as expected in the womb. The researchers examined the fluid surrounding the developing babies to identify chemical markers of growth problems, then tested whether folic acid supplementation could reverse these problems and improve placental function.

The study measured multiple aspects of fetal development including size measurements, weight, and placental structure. The researchers also analyzed how folic acid changed the activity of genes in the placenta, specifically looking at proteins that control whether genes are turned on or off.

This type of research is important because it helps scientists understand the biological mechanisms behind growth problems before testing potential treatments in humans. By studying how folic acid works at the molecular level, researchers can design better clinical trials and understand which patients might benefit most.

Understanding how folic acid works at the genetic level is crucial because it moves beyond simply knowing ‘it helps’ to understanding ‘why it helps.’ This knowledge helps doctors predict which pregnant people might benefit from folic acid supplementation and allows for more targeted treatment approaches in the future.

This is a laboratory-based research study, which means it provides important foundational knowledge but hasn’t yet been tested in pregnant humans. The findings are promising but should be considered preliminary. The research was published in a peer-reviewed scientific journal, meaning other experts reviewed the work before publication. However, results from animal studies don’t always translate directly to humans, so clinical trials in pregnant people would be needed to confirm these benefits.

What the Results Show

Folic acid supplementation produced significant improvements in fetal growth, with increases in crown-rump length (head-to-bottom measurement), body weight, and placental weight—all showing statistical significance (P < 0.001, meaning there’s less than a 0.1% chance these results happened by random chance).

The placenta showed structural improvements with folic acid treatment. In untreated growth-restricted pregnancies, the placenta developed an abnormal structure with excessive growth of one region (the labyrinth zone), increasing by 40%. Folic acid supplementation reduced this overgrowth by 10% and appeared to restore more normal placental architecture.

At the genetic level, folic acid changed how genes were regulated in the placenta. Specifically, it reduced expression of a protein called HDAC1 (histone deacetylase 1) and increased acetylation marks on histone proteins—essentially turning on genes that promote healthy placental cell growth and function.

The researchers identified specific chemical imbalances in the amniotic fluid of growth-restricted pregnancies, including elevated hypoxanthine and reduced valproic acid levels, suggesting these could serve as markers for detecting fetal growth problems.

The study found that folic acid enhanced trophoblast proliferation—meaning it increased the growth and multiplication of the specialized cells that make up the placenta and directly interact with maternal blood. This suggests folic acid improves the placenta’s capacity to exchange nutrients and oxygen with the mother’s bloodstream. The research also identified specific metabolic pathways (arginine/proline metabolism) that are disrupted in growth-restricted pregnancies, suggesting multiple biological systems are affected.

This research builds on existing knowledge that folic acid is essential for fetal development and that placental dysfunction contributes to growth restriction. Previous studies showed folic acid’s importance in preventing birth defects, but this research goes deeper by explaining how folic acid might specifically fix placental structure and function problems. The focus on epigenetic mechanisms (how genes are turned on and off) represents a newer understanding of how nutrients influence fetal development beyond simple genetic inheritance.

This study was conducted in laboratory animals, not in pregnant humans, so results may not directly apply to human pregnancies. The sample size and specific animal model used weren’t detailed in the abstract. The research doesn’t tell us the optimal dose of folic acid, the best timing for supplementation, or whether benefits would occur in all pregnancies with growth problems or only specific types. Additionally, the study doesn’t address potential side effects or interactions with other medications. Long-term follow-up data on offspring development wasn’t included. These limitations mean the findings are promising but preliminary, requiring human clinical trials before clinical recommendations can be made.

The Bottom Line

Based on this research: Pregnant people should continue taking prenatal vitamins containing folic acid as recommended by their healthcare provider (typically 400-800 micrograms daily). If fetal growth restriction is diagnosed, discuss with your doctor whether additional folic acid supplementation might be beneficial—this research suggests it may help, but individual recommendations should be personalized. This evidence is considered preliminary (confidence level: moderate for animal studies, pending human confirmation).

This research is most relevant to: pregnant people diagnosed with fetal growth restriction, healthcare providers managing high-risk pregnancies, and researchers developing new treatments for pregnancy complications. People planning pregnancy should ensure adequate folic acid intake. This research doesn’t apply to non-pregnant individuals unless they’re planning pregnancy. Those with certain genetic conditions affecting folate metabolism should consult their doctor about appropriate folic acid levels.

In the animal studies, improvements in fetal growth and placental structure were observed during pregnancy. In humans, if folic acid supplementation is recommended after a growth restriction diagnosis, benefits would likely develop over weeks to months of pregnancy. However, the timeline for human pregnancies hasn’t been established and would depend on when supplementation begins and the severity of growth restriction. Results wouldn’t be immediate but would be monitored through regular ultrasounds.

Want to Apply This Research?

  • If prescribed folic acid supplementation for pregnancy concerns, track daily intake (yes/no) and note any side effects. For pregnancies with growth concerns, track ultrasound measurements at each appointment to monitor fetal growth rate and placental function markers if available.
  • Set a daily reminder to take prenatal vitamins with folic acid at the same time each day. If higher-dose folic acid is recommended, use the app to log timing and dosage. Maintain consistent prenatal care appointments to monitor fetal growth and placental health through ultrasound.
  • Long-term tracking should include: regular prenatal appointment dates and ultrasound findings (especially fetal measurements and placental appearance), daily folic acid supplementation adherence, any pregnancy symptoms or concerns, and birth outcomes. After delivery, track infant growth and development milestones to assess long-term effects.

This research is based on laboratory animal studies and has not yet been tested in pregnant humans. The findings are preliminary and should not be used to make individual medical decisions without consulting a healthcare provider. Pregnant people should continue following their doctor’s recommendations regarding folic acid supplementation. If fetal growth restriction is diagnosed, discuss all treatment options, including potential folic acid supplementation, with your obstetrician or maternal-fetal medicine specialist. This summary is for educational purposes and does not constitute medical advice. Always consult with qualified healthcare professionals before making changes to prenatal care or supplementation.