Hispanic Origin and Neural Tube Defects in Houston/Harris County, Texas: II. Risk Factors

Abstract

Several investigators have reported Hispanics to be at elevated risk for neural tube defects (anencephaly and spina bifida). Factors contributing to this risk have not been established. The authors conducted a case-control study of neural tube defects (NTDs) among births occurring in Harris County, Texas, from April 1, 1989, through December 31, 1991. Through the use of multiple ascertainment methods, 59 cases of anencephaly and 32 cases of spina bifida were detected. Controls (n = 451) were sampled for the same time period from Harris County vital records. Regardless of how Hispanic ethnicity was classified, having a Hispanic parent was a risk factor for both anencepahly and spina bifida. The primary etiologic question was whether increased NTD risk in Hispanics is explained by maternal diabetes or by other factors (e.g., maternal birthplace, prenatal care, reproductive history, age, socioeconomic status). Mexico-born Hispanics were no more likely than Texas-born Hispanics to deliver a fetus or infant with an NTD. Having a Hispanic mother was a risk factor for anencephaly among infants born to women with early prenatal care (odds ratio (OR) = 4.54, 95% confidence interval (CI) 2.21-9.40) but not for those born to latecomers. Earlier prenatal care seemed "protective" for non-Hispanics (OR = 0.18, 95% CI 0.06-0.65) but not for Hispanics. After simultaneous adjustment for eight variables in multivariate analysis, having a Hispanic (versus non-Hispanic) mother remained a strong risk factor for both anencephaly (OR = 2.58, 95% CI 1.19-5.61) and spina bifida (OR = 3.71, 95% CI 1.48-9.31). Any previous pregnancy termination/fetal loss was also associated with anencephaly in a final logistic regression model (OR = 2.48, 95% CI 1.20-5.10), and having a teenage mother (aged < 20 years) approached significance (OR = 2.21, 95% CI 0.92-5.31). "Hispanic mother" was the only study variable significantly associated with spina bifida in multivariate analysis. Results for diabetes suggested no association with anencephaly (OR = 1.24, 95% CI 0.25-6.17). An increased risk of NTDs among Hispanics remained after controlling for other factors. For anencephaly, this risk might be partially explained by economic and cultural differences between Hispanics and non-Hispanics, and the effect of these factors on rates of prenatal diagnosis and elective pregnancy termination.

Fumonisin B1-induced Sphingolipid Depletion Inhibits Vitamin Uptake via the Glycosylphosphatidylinositol-anchored Folate Receptor

“…Since folate deficiency during the first trimester of pregnancy is associated with an increased risk of neural tube defects in the developing fetus (43)(44)(45), it is possible that some instances of high rates of occurrence of these birth defects unexplained by known causes might be linked to dietary exposure to fumonisin B 1 . For instance, high rates of neural tube defects have been observed in Cameron County, TX from 1990 to 1991 (46,47) and in Harris County, TX from 1989 to 1991 (48,49). The prevalence of these birth defects was high among Hispanics (48), for whom corn and corn products are expected to represent a sizable portion of their diet.…”

Genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) in ethnic populations in Texas; a report of a novelMTHFRpolymorphic site, G1793A

“…Our interest in the population in Texas stems from reports of increased risk of NTD, especially among Hispanics [Can®eld et al, 1996a[Can®eld et al, , 1996b. Some studies reported low folate intake among Hispanics and African-Americans [Wright et al, 1998;Ford and Ballew, 1998].…”

Spinal dysraphism: A challenge continued to be faced by neurosurgeons in developing countries

“…[71617] Neural tube defects are etiologically heterogeneous[21819] and the epidemiology of neural tube defects is complex. [13] Many risk factors associated with increased risk for neural tube defects have been identified, including folic acid deficiency,[13] older or very young mothers,[13] modestly increased risk in primiparous,[11] previous spontaneous abortions,[20] short intervals between pregnancies,[21] multiple gestations,[22232425] maternal obesity and elevated body mass index,[262728] maternal diabetes,[20] lower socioeconomic status,[13] tea use in the period before and during the first trimester,[29] zinc deficiency, lead, and high levels of organic matter[30313233] and drugs (including anti-epileptic medications). [13]…”