Correlation on hemoglobin concentration and the development of cognition among pre-school children / 中华流行病学杂志

Objective Our purpose was to evaluate the association between hemoglobin concentration (Hb) and cognitive ability of children at 4-6 years of age in 21 counties/cities in China.Methods A total number of 7331 children born during 1993-1996 were randomly selected from 21 counties or cities in Hebei,Jiangsu and Zbejiang provinces,Hb concentration of children were measured followed by three tests including full-scale,verbal and performance intelligence quotient (IQ) test performed by Chinese-Wechsler Intelligence Scale for Children,one year later.Results There were a 0.7 point difference in mean verbal scale IQ(P=0.144) and a 0.9 point difference in both mean performance and full-scale IQ (P=0.055 and 0.079,respectively) between anemia and non-anemia groups.Compared with children with non-anemia,children with anemia were 1.3-fold more likely to score poorly in verbal IQ and operational IQ (95%CI:1.1-1.6,1.1-1.5,respectively) and 1 A-fold more likely to have had poor scores in full-scale IQ(95%CI:1.2-1.6) after controlled for children's gender,age at intelligence test,region,parity and mother's IQ,education level,occupation.Participants were divided into 5 sub-groups according to Hb concentration of every 20 percentile.Verbal IQ scores of the lowest(Hb＜110 g/L),moderate (117 g/L≤Hb＜122 g/L) and the highest Hb concentration groups (Hb≥130 g/L) were 90.6±18.1,94.0±17.6 and 91.0±16.4,respectively.Performance IQ scores were 102.2±15.7,104.6±14.8 and 100.5±14.9,respectively.Full-scale IQ scores were 95.94±17.3,99.0±16.4 and 95.2±15.6,respectively.Children with both low and high hemoglobin levels did poorly in all intelligence tests than children with moderate Hb concentration (P＜0.001).After controlling for confounding factors,children with the lowest concentration were 1.4-fold more likely to have had poor verbal and performance scores than children with moderate Hb concentration (95% CI:1.1-1.7,1.1-1.8,respectively) and 1.5-fold (95% CI:1.2-1.8) more likely to have had poor full-scale scores than those with moderate Hb concentration.The association between high Hb concentration and low IQ scores disappeared in the multivariate model.Conclusion Low Hb concentration might have adversely affected children' s cognitive development.

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

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%CI:1.13-2.11)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.

Premature, low birth weight, small for gestational age and childhood cerebral palsy / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the relationship between perinatal risk factors such as premature, low birth weight, small for gestational age and childhood cerebral palsy (CP).</p><p><b>METHODS</b>A cross sectional survey was carried out among 305,263 children aged 1 - 6 years old in seven cities of Jiangsu Province, China from May to July 1997. The perinatal risk factors were analysed.</p><p><b>RESULTS</b>Four hundred and eighty-four cases of CP were found among this population. The prevalence of CP for children aged 1 - 6 years old was 1.59 per thousand. The prevalence of CP were strongly correlated to prematurity (RR = 25.16), low birth weight (RR = 19.63), and also highly correlated to small for gestational age (RR = 4.34). For smaller groups divided by small for gestational age (SGA), appropriate for gestational age (AGA), large for gestational age (LGA) and then by gestational age, prematurity was found to be at high risk in SGA (RR = 9.29), AGA (RR = 28.34) and LGA (RR = 21.41) groups. For groups divided by gestational age and then by SGA, AGA and LGA, SGA was found to have significantly high risk in premature (RR = 1.45), mature (RR = 4.41) and postmature (RR = 3.19) groups. Nine groups were divided by the gestational age along with SGA, AGA and LGA, rates of CP were found to be significantly higher in most groups than in the term AGA group. Compared with the rate of CP in the term AGA group, the RR were calculated and showed as followings (from higher to lower), premature SGA (RR = 40.99), premature AGA (RR = 28.34), premature LGA (RR = 21.08), postmature SGA (RR = 8.39), mature SGA (RR = 4.41) and postmature AGA (RR = 2.63).</p><p><b>CONCLUSION</b>Prematurity and small for gestational age are both independent risk factors for cerebral palsy. Postmaturity and large for gestational age are not risk factors.</p>

The epidemiology of neural tube defects in high-prevalence and low-prevalence areas of China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the epidemiology of neural tube defects (NTDs) in high- and low-prevalence areas of China.</p><p><b>METHODS</b>Birth defects surveillance data, collected from 1992 through 1994 was analyzed. These data were collected as part of the Sino-American cooperative project on NTDs prevention. We classified NTDs as anencephaly, encephalocele, high-level and low-level spina bifida (SB) according to location of the lesion (high vs low) and whether the defect was isolated or occurred in association with other birth defects. Rates were compared in the high-prevalence (North) region and the low-prevalence (South) region, after adjusted for classification, urban and rural, season and sex, and calculated the adjusted rate of NTDs.</p><p><b>RESULTS</b>Among seven hundred and eighty-four NTDs cases in 326 874 recorded births (include in livebirth, stillbirth and fetal death with a gestational age of at least 20 weeks), the overall NTDs prevalence in the North was 5.57/1,000 births, and in the South was 0.88/1 000. There were also significant differences in the prevalence of anencephaly, encephalocele, high-level and low-level SB between North (0.97, 0.49, 2.75 and 1.11/1,000 birth) and South (0.36, 0.15, 0.21 and 0.14/1,000 birth) (P < 0.01), with adjusted prevalences in the North 3 - 7 times higher than those in the South. There were significant difference between urban (2.04) and rural areas (6.57/1,000 birth) in the North (P < 0.01), urban (0.52) and rural areas (0.95/1,000 birth) in the South (P < 0.05). Adjusted prevalence rates in the rural were 3 - 4 times higher than those of urban in the North and 1.6 - 1.9 times higher than in the South; The seasonal rate of high-level SB increased between September and November in the North (3.44/1,000 birth), while the seasonal rate of anencephaly decreased between September and November (0.18/1,000 birth) in the South. However there were no seasonal changes in other classified NTDs both in the South and North.</p><p><b>CONCLUSIONS</b>The birth prevalence of NTDs in the North of China was the highest in the world. There were significant differences between the North and the South, urban and rural. There was seasonal change in high-level SB in the North, which was in accordance to the phenotype of NTDs. It was suggested that there might exist etiological heterogeneity among anecephalus, low- and high-level SB.</p>

Sex distribution of neural tube defects and their birth outcome in high- and low-prevalence areas of China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To describe and analyze epidemiological characteristics of babies with neural tube defects (NTD) by sex and birth outcome in a high-prevalence and a low-prevalence areas of China.</p><p><b>METHODS</b>Birth defects surveillance data collected from 1992 through 1994, as a part of the Sino-American cooperative project on NTD prevention, were used to classify NTD as four categories, i.e., anencephaly, encephalocele, high-level and low-level spina bifida according to the sites of lesion (high vs. low level lesion were cervicothoracic and lumbosacral, respectively). Each category was sub-classified, according to single or compound defect, as isolated external defects (including those with NTD only) or multiple external defects (including those with NTD and another major external birth defects that is not the sequence of a defect such as cleft lip with or without cleft palate). The rates of anencephalus, encephalocele, high- and low-level spina bifida (SB) in males and females and their sex ratios were calculated, adjusted for urban and rural areas, season, category and birth outcome by sex and sites of lesions (high vs. low).</p><p><b>RESULTS</b>Totally, 784 NTD cases were identified from 326 874 recorded births (including live births, stillbirths and fetal deaths with a gestation age of at least 20 weeks). The prevalence rates of anencephalus (1.30 per 1 000 female births) and high-level SB (3.99) in females were higher than those (0.66 and 1.66 per 1 000 male births) in males in the high-prevalence northern regions; with adjusted prevalence rates of females 1.8 - 2.1 times greater than those of males. In the low-prevalence southern regions, the prevalence of high- (0.32 per 1 000 female births) and low-level SB (0.21) in female were higher than those in males, with high- and low-level SB rate of 0.10 and 0.09 per 1 000 male births), with adjusted rates for females of 1.3 - 1.6 times higher than in males. Isolated NTD accounted for more than 80% of all NTD cases, and the prevalence of isolated NTD in females (2.57) was higher than that in males (1.40).</p><p><b>CONCLUSIONS</b>The sex differences in NTD existed between north and south, in accordance with the phenotype of NTD. It suggested that proportion of high level SB and anencephalus in females could increase as the prevalence of NTD going up, anencephaly, high- and low-level SB had the different genetic and environmental background.</p>