Abstract: 【Abstract】Objective To analyze the effect of different levels of dietary iron intake during pregnancy on the risk of developing small for gestational age (SGA). Method A nested case-control study was conducted among 8,325 mother–infant pairs registered and followed up until delivery at Gansu Provincial Maternity and Child Health Care Hospital between January 2010 and December 2012. Based on whether the infants were SGA, the subjects were divided into the SGAgroup (n=666) and the appropriate for gestational age (AGA) group (n=7 659). Dietary surveys were performed using the 24-hour dietary recall method during the first, second, and third trimesters, respectively. The daily iron intake for each period was estimated according to the China Food Composition Table, and the follow-up was continued until delivery. Statistical regression analysis were employed to assess the effects of dietary iron intake levels during different pregnancy periods on the occurrence of SGA. Result Compared with the AGA group, mothers in the SGA group were younger, had lower educational attainment and lower per capita monthly income, gained less weight during pregnancy, had higher rates of active and passive smoking and hypertensive disorders of pregnancy, had higher proportion of gestational hypertension,had lower rates of mineral and iron supplementation during pregnancy, and had shorter parental heights, the differences were all statistically significant (all P<0.05). Regarding dietary iron intake among mothers who delivered SGA infants, 395 (59.31%) cases and 300 (45.05%) cases met the recommended nutrient intake (RNI) during the first and second trimesters, respectively. These proportions were lower than those in mothers who delivered AGAinfants. The results of multivariate Logistic regression analysis revealed that the levels of dietary iron intake below the estimated average requirement (EAR) during the first trimester (OR=1.497, 95% CI: 1.185-1.892, P<0.001) and the second trimester (OR=1.223, 95% CI: 1.006-1.487, P=0.044) were statistically significant risk factors for the occurrence of SGA. After further stratifying SGA into different subtypes, the levels of dietary iron intake below the EAR during the first trimester remained a statistically significant risk factor for term SGA (OR=1.492, 95% CI: 1.168-1.907, P<0.001). Conclusion The levels of dietary iron intake below the EAR in first and second trimesters will increase the risk of SGA, so it is recommended that pregnant women increase their dietary iron intake levels moderately in first and second trimesters.
侯梦薇 马玲玲 杨早娟 毛宝宏 易彬. 孕期膳食铁摄入量对小于胎龄儿的影响[J]. 发育医学电子杂志, 2025, 13(6): 428-434.
Hou Mengwei, Ma Lingling, Yang Zaojuan, et al. Efect of dietary iron intake level during pregnancy on small for gestational age infants. Journal of Developmental Medicine(Electronic Version), 2025, 13(6): 428-434.
2025, Vol. 13 
