Iranian Journal of Neonatology

Iranian Journal of Neonatology

Folic Acid Supplementation and the Risk of Small or Large for Gestational Age Births: A Cohort-Based Study from Semnan, Iran

Document Type : Original Article

Authors
Maryam Hemmati 1
Fatemeh Paknazar 1
Majid Mirmohammadkhani 1
Kobra Bahrampour Juybari 2
1 Social Determinants of Health Research Center, Semnan University of Medical Sciences, Semnan, Iran
2 Immunogenetics Research Center, Mazandaran University of Medical Sciences, Sari, Iran
10.22038/ijn.2026.92516.2799
Abstract
Background: Folic acid supplementation (FAS) has been shown to prevent neural tube abnormalities. However, the association between maternal FAS and fetal development outcomes beyond the twelfth week of pregnancy is still unclear. This cohort study aimed to explore the effects of maternal FA intake prior to and during pregnancy on the incidence of small for gestational age (SGA), large for gestational age (LGA), low birth weight (LBW), and high birth weight (HBW).
Methods: A total of 505 pregnant women who visited Semnan health centers between 2018 and 2021 participated in this prospective Semnan birth cohort study. Data regarding FAS intake were recorded for different periods. Univariate comparisons employed t-tests, one-way analysis of variance (ANOVA), and chi-square tests. To control for confounders, multivariable logistic regression and general linear models (ANCOVA) were used, adjusting for maternal age, BMI, education, employment, and residence. Adjusted odds ratios and mean differences with 95% CIs were calculated.
Results: We found that ongoing FAS (400 µg/day) from 1 month before conception and throughout all three trimesters significantly increased the risk of HBW (adjusted OR = 2.95, 95% CI: 1.02–8.52) without affecting the incidence of SGA, LBW, or LGA.
Conclusion: To verify these results, it is recommended to conduct further studies or large-scale trials along with monitoring folate levels during the entire pregnancy.
Keywords
Birth cohort
Birth weight
Folic acid
Infant
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Iranian Journal of Neonatology
Volume 17, Issue 4
Autumn 2026
Pages 32-38