OBJECTIVETo study the association between transforming growth factor alpha gene (TGFalpha) TaqI variant and nonsyndromic cleft lip with or without cleft palate (nsCL/P) in Chinese population, and the interaction with parental smoking.METHODSTGFalpha TaqI variant was detected using RFLP-PCR for DNA samples of the 170 triads with nsCL/P affected child. We performed the transmission/disequilibrium test (TDT) and the family-based association study (FBAT) to test the associations between this variant and risk of nsCL/P.RESULTSIt was not found significant distortion of C2 allele at TGFalpha TaqI locus in nsCL/P groups (P > 0.05), however, by stratified analysis, we found that the rate of C2 allele transmission among nuclear families whose fathers were smoking was 1/5 (0.062 - 0.711) as compared with that among nuclear families whose fathers were not smoking, and the OR of interaction between TGFalpha variant and parental smoking is 0.102 (0.017 - 0.619).CONCLUSIONThe parental smoking may interact with TGFalpha variants of Chinese populations in occurrence of nsCL/P, but it remains to have more investigations.

Objectives To evaluate the optimal maternal weight gain patterns in twin pregnancy. Methods By describing the relationship between perinatal mortality,low birth weight and maternal weight gain in twins,find the optimal range of weight gain during pregnancy. Results Women with weight gain below 16 kg in pregnancy accounted for 62.9 %(892/1 417),below 10 kg for 21.2 %(300/1 417).The perinatal mortality was below 3 % as the maternal weight gain ranged between 16.0 and 24.0 kg.With the increasing of weight gain,the incidence of low-birth weight infants declined. Conclusion The results suggested,that maternal weight gain was associated with the perinatal outcome in twins.A range of 16.0～24.0 kg of maternal weight gain wowld be optimal in twin pregnancy.

Objective To describe the epidemiological characteristics of oral clefts in 5 counties of Hebei Province of China, between 1993 and 1996. Methods Detailed data were obtained through the Birth Defects Surveillance System that was established in 1992. The study population comprised the total live and stillbirths (with a gestational age of at least 20 weeks) in the counties between 1993 and 1996. Birth prevalence of oral clefts (including cleft palate alone, cleft lip+ /-cleft palate) was calculated for specific birth populations. Results In the period of 1993-1996, the overall prevalence of oral clefts was 2. 080 total births, and the rates of cleft palate and cleft lip +/-cleft palate were 0. 300 and 1. 780 , respectively. The highest rate (3. 350 ) of oral clefts was seen in Yuanshi county, and the lowest (1. 660 )in Xianghe county. the highest birth prevalence (2. 700 ) of oral clefts was in the year 1993, and the lowest (1. 680 ) in 1995. There was no significant seasonal variation of oral clefts. The overall male/female ratio was 1. 38 : 1. The birth prevalence rates of cleft lip +/-cleft palate for male and female were 2. 080 and 1. 430 respectively (X2=4.14,P0. 05). Conclusion The birth prevalence of oral clefts in the 5 counties of Hebei Province was persistently high, and sex differences existed during the period of between 1993 and 1996. Possible environmental factors and indicated and differences in susceptibility exist between two sexes.

Objective To characterize the trend of perinatal morbidity and mortality of twins. Methods Twin data were collected from three provinces from 1993 to 2000 with a perinatal health surveillance system. Descriptive analysis was performed for perinatal morbidity and mortality. Results 7 120 twins were included in the analysis. Perinatal mortality of twins declined from 103 per thousand in 1993 to 54.8 per thousand in 2000. Caesarean section rate rose from 26. 5 % in 1993 to 66. 6 % in 2000. Fetal distress fluctuated, and neonatal pneumonia rose slightly. Neonatal pathological jaundice, sclerema neonatorum, and respiratory distress syndrome declined steadily. Conclusion Twin perinatal mortality declined during the observational period, and the drops in neonatal morbidity might contribute to the declining.