Are early-life socioeconomic conditions directly related to birth outcomes? Grandmaternal education, grandchild birth weight, and associated bias analyses

Citation

Huang, J. Y.; Gavin, A. R.; Richardson, T. S.; Rowhani-Rahbar, A.; Siscovick, D. S.; & Enquobahrie, D. A. (2015). Are early-life socioeconomic conditions directly related to birth outcomes? Grandmaternal education, grandchild birth weight, and associated bias analyses. American Journal of Epidemiology. vol. 182 (7) pp. 568-578

Abstract

Grandmaternal education may be related to grandchild birth weight (GBW) through maternal early-life development; however, conventional regression models may be endogenously confounded. Alternative models employing explicit structural assumptions may provide incrementally clearer evidence. We used data from the US National Longitudinal Study of Adolescent to Adult Health (1995-2009; 1,681 mother-child pairs) to estimate "direct effects" of grandmaternal educational level (less than high school, high school diploma or equivalent, or college degree) at the time of the mother's birth on GBW, adjusted for maternal life-course factors: maltreatment as a child, education and income as an adult, prepregnancy overweight, and prenatal smoking. Using conventional and marginal structural model (MSM) approaches, we estimated 54-g (95% confidence interval: -14.0, 122.1) and 87-g (95% confidence interval: 10.9, 162.5) higher GBWs per increase in educational level, respectively. The MSM allowed simultaneous mediation by and adjustment for prepregnancy overweight. Estimates were insensitive to alternate structural assumptions and mediator parameterizations. Bias analysis suggested that a single unmeasured confounder would have to have a strong influence on GBW (approximately 150 g) or be greatly imbalanced across exposure groups (approximately 25%) to completely explain the findings. Coupling an MSM with sensitivity analyses provides some evidence that maternal early-life socioeconomic environment is directly associated with offspring birth weight.

URL

http://dx.doi.org/10.1093%2Faje%2Fkwv148

Keyword(s)

bias (epidemiology) birth weight early life grandmaternal education marginal structural models socioeconomic status

Notes

1476-6256 Huang, Jonathan Y Gavin, Amelia R Richardson, Thomas S Rowhani-Rahbar, Ali Siscovick, David S Enquobahrie, Daniel A Journal article Am J Epidemiol. 2015 Aug 17. pii: kwv148.

Reference Type

Journal Article

Journal Title

American Journal of Epidemiology

Author(s)

Huang, J. Y.
Gavin, A. R.
Richardson, T. S.
Rowhani-Rahbar, A.
Siscovick, D. S.
Enquobahrie, D. A.

Year Published

2015

Volume Number

182

Issue Number

7

Pages

568-578

Edition

August 19, 2015

DOI

10.1093/aje/kwv148

Reference ID

6978