[Prenatal screening for major fetal heart defects by training sonographers in township hospitals and county health centers: a feasibility study].

OBJECTIVE: To explore the feasibility of screening for major fetal heart disease by training sonographers in township or county level hospitals. METHODS: Training of B ultrasound scan for congenital heart defects was given to the sonographers from one county hospital, and thirteen township hospitals (or the district hospitals), and training of fetal echocardiography was given to sonographers from four city/county hospitals. The trained sonographers who had passed the examinations and had obtained qualifications after six months of independent practice began to screen fetal congenital heart defects. To evaluate the effectiveness, sensitivity and specificity of screening was calculated by using the diagnosis of expert neonatal/fetal echocardiographers as the gold standard. RESULTS: A total of 3 425 fetuses received one fetal B ultrasound screening, one fetal echocardiography and one neonatal echocardiography from April 1, 2004 to December 31, 2005. One hundred and sixty-five B ultrasound screening images (4.9%) from township hospitals and fifty-six fetal echocardiography images (1.7%) from county or city centers couldn't be reviewed because of poor quality. The sensitivity of fetal B ultrasound screening in the township and county hospitals was 30% and 0, and the specificity 93.3% and 99.9%, respectively. Nine fetuses with a major congenital heart disease were eventually found by the trained sonographers, and two cases were misdiagnosed and two unnoticed. The total sensitivity and specificity of fetal echocardiography were 81.8% and 99.9%, respectively. The sensitivity in the county and city hospitals was 66.7% and 100%, respectively. The specificity in the county and city hospitals was 99.9% and 100%, respectively. CONCLUSION: Under the current circumstances, township hospitals are unable to perform effective fetal cardiac screening. Screening on fetal congenital heart disease is suggested to be taken by trained sonographers in county and city level medical centers.

[Correlation on hemoglobin concentration and the development of cognition among pre-school children].

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 Zhejiang 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 1.4-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 /= 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 95.9 +/- 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 pre-school children].

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, 104.5 ± 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.

[Sex distribution of neural tube defects and their birth outcome in high- and low-prevalence areas of China].

OBJECTIVE: 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. METHODS: 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). RESULTS: 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). CONCLUSIONS: 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.

[The epidemiology of neural tube defects in high-prevalence and low-prevalence areas of China].

OBJECTIVE: To describe the epidemiology of neural tube defects (NTDs) in high- and low-prevalence areas of China. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

A population-based birth defects surveillance system in the People's Republic of China.

We describe a unique birth defects surveillance system in the People's Republic of China. The system was instituted in March 1992 as a component of an evaluation of the effectiveness of a public health campaign using periconceptional folic acid supplementation to prevent neural tube defects, and currently surveys birth cohorts of approximately 150 000 infants per year. Local health care providers collect information in the form of detailed written descriptions and photographs of affected infants. The system allows for detection of birth defects at the local level with later definitive classification and coding; however, information is limited to structural anomalies that are visible on physical examination. This birth defects surveillance system provides an extensive database of infants with major and minor external structural anomalies, including the unique feature of a photographic record for most cases. These data can be used for aetiological studies, descriptive epidemiology and identification of unusual trends.

[Premature, low birth weight, small for gestational age and childhood cerebral palsy].

OBJECTIVE: To investigate the relationship between perinatal risk factors such as premature, low birth weight, small for gestational age and childhood cerebral palsy (CP). METHODS: 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. RESULTS: 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). CONCLUSION: Prematurity and small for gestational age are both independent risk factors for cerebral palsy. Postmaturity and large for gestational age are not risk factors.