The impact of obesity on maternal morbidity and feto-infant outcomes among macrosomic infants

Abstract

Objective. To estimate the contribution of obesity to maternal complications, neonatal morbidity and mortality among macrosomic births.

Design. A population-based retrospective cohort design using State of Missouri maternally linked birth cohort files.

Methods. Using pre-gravid body mass index (BMI), we categorized mothers of 116,976 singleton macrosomic live births as non-obese (BMI < 30) or obese (BMI ≥ 30). We used logistic regression models to generate adjusted odd ratios for pregnancy and neonatal complications. We also estimated the proportion of potentially preventable excess maternal and neonatal complications that could be eliminated among obese women with infant macrosomia at various levels of pre-pregnancy obesity reduction.

Result. Obese mothers with macrosomic infants were at elevated risk for chronic hypertension (odds ratio (OR) = 6.78 [95% confidence interval (CI): 5.82–7.88]), insulin-dependent diabetes mellitus, (OR = 2.60 [CI: 2.34–2.88]) other types of diabetes mellitus (OR = 2.83 [CI: 2.65–3.02]) and preeclampsia (OR = 2.49 [CI: 2.33–2.67]). Macrosomic infants of obese mothers were at greater risk for hyaline membrane disease (OR = 2.14 [CI: 1.73–2.66]), extended assisted ventilation (OR = 1.71 [CI: 1.44–2.04]), birth injury (OR = 1.58 [CI: 1.37–1.84]) and meconium aspiration syndrome (OR = 1.42 [CI: 1.09–1.87]). The proportion of preventable excess maternal morbidity was 60%, 45%, 30% and 15%, assuming an effective pre-conception intervention that could reduce obesity down to 0%, 25%, 50% and 75% of its current level, respectively. The corresponding proportion of preventable excess neonatal complications would be 40%, 30%, 20% and 10%, respectively.

Conclusion. Among obese mothers with macrosomic births, a substantial proportion of maternal and neonatal morbidity could be averted through effective pre-conception interventions.

Keywords:

• Macrosomia
• obesity
• maternal complications
• neonatal complications
• preventive fraction

Acknowledgements

This study was funded by a grant from the Flight Attendant Medical Research Institute (FAMRI: 024008) to the first author (Hamisu Salihu, MD, PhD). The funding agency did not play any role in any aspect of the study. The authors thank the Missouri Department of Health and Senior Services for providing the data files used in this study.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.