Influence of hemoglobin level during early gestation on the development of cognition of preschool children / 中华流行病学杂志

ABSTRACT

Objective The purpose of this study was to evaluate the effect of hemoglobin (Hb) level during early gestation on the cognitive development of children at 4-6 years of age.Methods A total number of 3609 children were randomly selected from all the live birth infants whose mothers participated in a community intervention trial during 1993-1996 in 13 counties or cities in Jiangsu and Zhejiang provinces. Hb concentration during early gestation was measured at first prenatal examination and intelligence quotients (IQ), including full-scale, verbal and performance were assessed using Chinese-Wechsler Intelligence Scale for Children in 2000-2001 when these children had a mean age of 68 months. Results Compared with children whose mothers were non-anemic during early gestation, children whose mothers were anemic had a 0.6 point higher mean verbal scale IQ, a 0.9 point higher mean performance IQ and a 0.8 point higher mean full-scale IQ.These differences were not statistically significant when children' s gender, age at intelligence test,region, parity and mother' s IQ, education level and occupation were adjusted for. When mother-child pairs were divided into 5 sub-groups of every 20 percentiles according to Hb concentration during early gestation, verbal IQ scores of the lowest(Hb＜ 103 g/L), the moderate(110 g/L≤ Hb＜ 116 g/L)and the highest Hb concentration group (Hb≥124 g/L) were 91.6 ± 18.9, 92.8 ± 18.2 and 90.3 ±18.6, respectively. The performance IQ scores were 104.7 ± 15.2, 1 04.5 ± 14.3 and 103.5 ±15.1, and full-scale IQ scores were 97.8 ± 17.3,98.4 ± 16.3 and 96.4 ± 17.4, respectively. After controlling for confounding factors, children whose mothers had highest Hb concentration were 54% (OR= 1.54,95%CI1.13-2.11)more likely to have poor verbal scores and 53% (OR= 1.53,95%CI 1.10-2.12)more likely to have poor full-scale scores than children whose mothers had moderate -Hb concentration. No statistical associations were noticed between high -Hb concentration and performance scores, or between low Hb concentration during early gestation and verbal, performance as well as full-scale score of pre-school children. Conclusion High maternal Hb concentration during early gestation might adversely affect children' s cognitive development.