Spina bifida phenotypes in infants or fetuses of obese mothers
✍ Scribed by Shaw, Gary M.; Todoroff, Karen; Finnell, Richard H.; Lammer, Edward J.
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 61 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0040-3709
No coin nor oath required. For personal study only.
✦ Synopsis
Background: A twofold or greater risk of neural tube defect (NTD)-affected pregnancy has been associated with prepregnant obesity, where obesity was defined as body mass index (BMI) of Ͼ29 kg/m 2 . Risks have been more elevated for spina bifida than for anencephaly.
Methods:
We investigated whether finer phenotypic classifications of spina bifida, in combination with other factors, were associated with a BMI of Ͼ29 kg/m 2 . Data were derived from a case-control study of fetuses and infants with NTDs among 1989 -1991 California births. Interviews were conducted with mothers of 277 spina bifida cases and 517 nonmalformed controls.
Results: Women with a BMI of Ͼ29 kg/m 2 compared with those Յ29 kg/m 2 revealed an odds ratio (OR) of 2.2 (95% confidence interval [95% CI] ϭ 1.4 -3.3) for spina bifida in their infants and fetuses. Elevated risks were observed for each spina bifida subphenotype, and risks varied by subphenotype: open spina bifida, OR ϭ 2.0 (1.2-3.1); closed (skin-covered), 3.3 (1.4 -7.5); isolated, 2.2 (1.4 -3.4); nonisolated, 1.9 (0.9 -4.2); high, 4.5 (2.1-9.6); low, 1.9 (1.2-2.9); open/ isolated/high, 7.1 (2.8 -18.1); and open/isolated/low, 1.8 (1.1-3.1). Risks were higher among female infants/fetuses and foreign-born Latinas, and for some phenotypes the risks were quite large, e.g., OR ϭ 8.3 (2.9 -23.6) for "closed" spina bifida among female infants/fetuses whose mothers were Ͼ29 kg/m 2 compared with males whose mothers were Յ29 kg/m 2 . Maternal periconceptional vitamin use was not observed to influence risk as greatly across phenotypes.
Conclusions:
The observed pathogenetic heterogeneity of prepregnant obesity and spina bifida risks suggests that there are likely to be several biologic mechanisms underlying the association.