[A case-control study on genetic and environmental factors regarding polydactyly and syndactyly].

OBJECTIVE: To explore the genetic and environmental factors related to the development of polydactyly and syndactyly, and to provide evidence for prevention on birth defects. METHODS: A hospital-based case-control study was conducted. 111 cases and 222 controls were interviewed with standardized questionnaires. Logistic regression models were used to select risk factors. RESULTS: Research data through univariate analysis showed that the occurrence of polydactyly and syndactyly were associated with educational level, annual average income per family member, meat and egg intake during early pregnancy, family heredity history, exposure to hazardous substance before pregnancy, serious pregnant reaction etc. of the pregnant women. As shown in multivariable logistic model, some factors, including annual average income of per family member (OR = 0.240), meat and egg intake during early pregnancy (OR = 0.182), could reduce the risk of the development of polydactyly and syndactyly. Other factors including family heredity history (OR = 10.187), exposure to hazardous substance before pregnancy (OR = 3.029), could increase the risk of developing polydactyly and syndactyly. The attributable risks (%) of family heredity history and exposure to hazardous substance before pregnancy were 90.18% and 66.99% respectively. CONCLUSION: Genetic factor was the leading cause on the development of polydactyly and syndactyly. In addition, environmental factors, such as family economic condition, nutritional status during early pregnancy and working condition before pregnancy were associated with the development of polydactyly and syndactyly.

[The status on care and nutrition of 774 children staying in rural areas while parents were in towns].

OBJECTIVE: To understand the status on care and nutrition of children living in the rural areas (so called 'left-behind' children) while their parents were seeking for jobs in the urban areas. METHODS: Cross-sectional study was employed in this investigation. The group of 'left-behind' children (n = 774) and the comparison group (n = 774) were identified. The ascertainment methods mainly included questionnaire, anthropometrics measurements, food-frequency, and laboratory examination. RESULTS: Data from this study revealed that the guardians of the 'left-behind' children had less ability to ensure daily food that the children demanded than the control group and the 'left-behind' children were more likely to be poorly attended (chi2 = 6.671, P = 0.036; xhi2 = 15.053, P = 0.001). Mothers who chose to work outside of their households would tend to choose bottle-feeding or decrease the duration of breastfeeding for their infants (chi2 = 5. 051, P = 0.031; t = -7.201, P = 0.001). The intake of milk and bean products in children younger than 2 years old and cereal intake in children aged 2 to 4 in the group of 'left-behind' children were obviously lower than that seen in the control group (t = -2.150, P = 0.032; t = -2.054, P = 0.040 respectively). The 'left-behind' children were in high prevalence of anemia, and showed significant difference when comparing with the control group (chi2 = 4.560, P = 0.033). CONCLUSION: Children under 'left-behind' situation were in poor nutrition. Recognition of this situation by the communities, parents and extended families would facilitate more attention and effective intervention programs to improve the situation.