Please cite this article as: Nohr EA, Villamor E, Vaeth M, Olsen J, Cnattingius S. Mortality in infants of obese mothers: is risk modified by mode of delivery? Acta Obstet Gynecol Scand 2012;91:DOI:10.1111/j.1600-0412.2011.01331.x.
MAIN RESEARCH ARTICLE
Mortality in infants of obese mothers: is risk modified by mode of delivery?
Article first published online: 19 JAN 2012
© 2012 The AuthorsActa Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology
Acta Obstetricia et Gynecologica Scandinavica
Volume 91, Issue 3, pages 363–371, March 2012
How to Cite
NOHR, E. A., VILLAMOR, E., VAETH, M., OLSEN, J. and CNATTINGIUS, S. (2012), Mortality in infants of obese mothers: is risk modified by mode of delivery?. Acta Obstetricia et Gynecologica Scandinavica, 91: 363–371. doi: 10.1111/j.1600-0412.2011.01331.x
- Issue published online: 21 FEB 2012
- Article first published online: 19 JAN 2012
- Accepted manuscript online: 29 NOV 2011 05:38AM EST
- Received: 17 August 2011, Accepted: 20 November 2011
- Maternal obesity;
- interpregnancy weight change;
- infant death;
- neonatal death;
- labor and delivery;
- high-risk pregnancy
Objective. To examine the association between maternal obesity and infant mortality, while including information about mode of delivery and interpregnancy weight change. Design. Register-based cohort study. Setting and population. A total of 1 199 183 singletons, including 3481 infant deaths, from the Swedish Birth Register 1992–2006. Methods. Maternal body mass index (BMI) was obtained from self-reports in early pregnancy and categorized as underweight (<18.5 kg/m2), normal-weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), obese (30–34.9 kg/m2) and extremely obese (≥35 kg/m2). Cox regression was used to estimate hazard ratios (95% confidence intervals). Infants of normal-weight women were the referent. Main outcome measures. Neonatal and infant mortality. Results. Infant mortality increased with increasing maternal fatness [adjusted hazard ratios 1.2 (1.1–1.3), 1.4 (1.2–1.6) and 2.1 (1.8–2.5) for overweight, obesity and extreme obesity, respectively]. When accounting for mode of delivery, neonatal mortality was increased in infants of obese and extremely obese mothers after spontaneous births [adjusted hazard ratios 1.8 (1.4–2.4) and 2.6 (1.8–4.0), respectively, after term births, and 1.4 (1.1–1.9) and 2.2 (1.5–3.3), respectively, after preterm births]. No excess risk was present for infants of obese mothers after induced term and preterm births (p-values for interaction <0.05). For post-neonatal mortality, no interaction between mode of delivery and maternal obesity was observed. In women with two subsequent pregnancies, high interpregnancy weight change >1 BMI unit (1 kg/m2) seemed to involve a modest increase in neonatal mortality in the second infant, but only after spontaneous births [adjusted odds ratio 1.3 (0.9–1.7)]. Conclusions. Maternal obesity, especially at levels that may involve cardiometabolic morbidity, was associated with increased mortality in the offspring.