A population-based case-control study of risk factors for neural tube defects in four high-prevalence areas of Shanxi province, China.

Shanxi province in Northern China has one of the highest reported prevalence rates of neural tube defects (NTD) in the world. To explore the risk factors for NTDs in Shanxi province, we carried out a population-based case-control study in four selected counties with prevalence rates >10 per 1000 births during 2003. Using a multi-logistic regression model analysis (alpha = 0.10), 158 NTD cases were compared with 226 control mothers. Maternal factors significantly associated with increased risk for an NTD were a primary school education or lower (adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 1.09, 4.97); a history of a previous birth defect-affected pregnancy (adjusted OR 5.27, 95% CI 0.98, 28.37); history of a fever or 'cold' (adjusted OR 3.36, 95% CI 1.68, 6.72); use of analgesic and antipyretic drugs (adjusted OR 4.89, 95% CI 0.92, 25.97); daily passive exposure to cigarette smoke (adjusted OR 1.60, 95% CI 0.94, 2.73); poor ventilation during heating (adjusted OR 3.91, 95% CI 0.75, 20.81); and consumption of >or= six meals per week containing pickled vegetables (adjusted OR 3.86, 95% CI 1.11, 13.47) during pregnancy. Factors which appeared to be protective were meat consumption one to three times per week (adjusted OR 0.62, 95% CI 0.37, 1.06), or >or= four times per week (adjusted OR 0.28, 95% CI 0.11, 0.77); and legume consumption >or= six times per week (adjusted OR 0.39, 95% CI 0.17, 0.89). Differences in risk were found between the two most common phenotypes, anencephaly and spina bifida. Most of the environmental factors had stronger positive and negative associations with risk for anencephaly rather than spina bifida, whereas history of a previous birth defect-associated pregnancy, as well as legume consumption, were more strongly associated with the risk for spina bifida than for anencephaly. The findings suggest that aetiological heterogeneity may exist between anencephaly and spina bifida.

[1]  K. Xiao,et al.  Central nervous system congenital malformations, especially neural tube defects in 29 provinces, metropolitan cities and autonomous regions of China: Chinese Birth Defects Monitoring Program. , 1990, International journal of epidemiology.

[2]  P. Taylor,et al.  Retrospective cohort study of risk-factors for esophageal cancer in Linxian, People's Republic of China , 1993, Cancer Causes & Control.

[3]  P. Corey,et al.  Water nitrates and CNS birth defects: a population-based case-control study. , 1988, Archives of environmental health.

[4]  P. Baghurst,et al.  Congenital malformations and maternal drinking water supply in rural South Australia: a case-control study. , 1984, American journal of epidemiology.

[5]  G. Shaw,et al.  Parental cigarette smoking and risk for congenital anomalies of the heart, neural tube, or limb. , 1996, Teratology.

[6]  E. Knox,et al.  Diet and Anencephalus , 1974, Proceedings of the Royal Society of Medicine.

[7]  G. Shaw,et al.  Maternal illness, including fever and medication use as risk factors for neural tube defects. , 1998, Teratology.

[8]  Lee-Yang Wong,et al.  A population-based birth defects surveillance system in the People's Republic of China. , 2003, Paediatric and perinatal epidemiology.

[9]  J. Roberts,et al.  THE RISK OF RECURRENCE AFTER TWO CHILDREN WITH CENTRAL-NERVOUS-SYSTEM MALFORMATIONS , 1967 .

[10]  K. Källén.  Maternal smoking, body mass index, and neural tube defects. , 1998, American journal of epidemiology.

[11]  J. Zhang,et al.  Association of the common cold in the first trimester of pregnancy with birth defects. , 1993, Pediatrics.

[12]  U. Bellati,et al.  Aspirin pretreatment potentiates hyperthermia-induced teratogenesis in the mouse. , 1998, American journal of obstetrics and gynecology.

[13]  Xiao-you Han,et al.  Esophageal cancer in Shanxi Province, People's Republic of China: a case-control study in high and moderate risk areas , 1992, Cancer Causes & Control.

[14]  B. Garabedian,et al.  Upper and lower neural tube defects: an alternate hypothesis. , 1993, Journal of Medical Genetics.

[15]  M. Kulldorff,et al.  Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California. , 1999, American journal of epidemiology.

[16]  C. N. Coelho,et al.  Methionine and neural tube closure in cultured rat embryos: morphological and biochemical analyses. , 1990, Teratology.

[17]  M. Khoury,et al.  Is there etiologic heterogeneity between upper and lower neural tube defects? , 1992, American journal of epidemiology.

[18]  Folic Acid.  Knowledge and use of folic acid by women of childbearing age--United States, 1995 and 1998. , 1999, MMWR. Morbidity and mortality weekly report.

[19]  K. Rothman,et al.  Folate Intake and the Risk of Neural Tube Defects: An Estimation of Dose-Response , 2003 .

[20]  J. Tian,et al.  [A study on risk factors of neural tube defects]. , 1996, Zhonghua yu fang yi xue za zhi [Chinese journal of preventive medicine].

[21]  Z. Li,et al.  Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention. , 2000, The New England journal of medicine.

[22]  L. Saxén,et al.  Influenza epidemic and congenital defects. , 1971, Lancet.

[23]  K. Shiota,et al.  Neural tube defects and maternal hyperthermia in early pregnancy: epidemiology in a human embryo population. , 1982, American journal of medical genetics.

[24]  J M Friedman,et al.  Clinical, genetic, and epidemiological factors in neural tube defects. , 1988, American journal of human genetics.

[25]  J. McCulloch,et al.  CHAPTER 7 – Implications for Prevention , 1972 .

[26]  D. Weir,et al.  Folate levels and neural tube defects. Implications for prevention. , 1995, JAMA.

[27]  Z. Li,et al.  Elevated rates of severe neural tube defects in a high-prevalence area in northern China. , 1997, American journal of medical genetics.

[28]  Prevention of neural tube defects: Results of the Medical Research Council vitamin study , 1991 .

[29]  M. Daley,et al.  Association of low maternal education with neural tube defects in Colorado, 1989-1998. , 2002, Public health.

[30]  E. Knox,et al.  Anencephalus and dietary intakes. , 1972, British journal of preventive & social medicine.

[31]  M. Edwards,et al.  Hyperthermia and birth defects. , 1995, Reproductive toxicology.

[32]  M. Gnant,et al.  Prevention of neural tube defects: Results of the Medical Research Council Vitamin Study , 1991, The Lancet.

[33]  M. Khoury,et al.  Maternal flu, fever, and the risk of neural tube defects: a population-based case-control study. , 1994, American journal of epidemiology.

[34]  M. Marazita,et al.  Neural tube defects, methylenetetrahydrofolate reductase mutation, and north/south dietary differences in China. , 1998, Journal of craniofacial genetics and developmental biology.

[35]  A. Czeizel,et al.  Prevention of the First Occurrence of Neural-Tube Defects by Periconceptional Vitamin Supplementation , 1992 .

[36]  G. Kissling,et al.  NEURAL TUBE DEFECT ETIOLOGY: NEW EVIDENCE CONCERNING MATERNAL HYPERTHERMIA, HEALTH AND DIET , 1992, Developmental medicine and child neurology.

[37]  R. Tharanathan,et al.  Grain legumes—a boon to human nutrition , 2003 .

[38]  G. Shaw,et al.  Maternal exposure to nitrate from drinking water and diet and risk for neural tube defects. , 2001, American journal of epidemiology.

[39]  Hong Wang,et al.  Correction: Prevention of Neural-Tube Defects with Folic Acid in China. , 1999, The New England journal of medicine.

[40]  B. Worthington-Roberts.  The role of maternal nutrition in the prevention of birth defects. , 1997, Journal of the American Dietetic Association.

[41]  G. Koren,et al.  Aspirin consumption during the first trimester of pregnancy and congenital anomalies: a meta-analysis. , 2002, American journal of obstetrics and gynecology.

[42]  H. Blom,et al.  Vitamin B12 insufficiency and the risk of fetal neural tube defects. , 2003, QJM : monthly journal of the Association of Physicians.

[43]  M. Li,et al.  Occurrence of nitroso compounds in fungi-contaminated foods: a review. , 1986, Nutrition and cancer.

[44]  G. Shaw,et al.  Socioeconomic status, neighborhood social conditions, and neural tube defects. , 1998, American journal of public health.

[45]  J D Erickson,et al.  Etiologic heterogeneity of neural tube defects: clues from epidemiology. , 1982, American journal of epidemiology.