Association between maternal obesity and offspring Apgar score or cord pH: a systematic review and meta-analysis

Previous results are inconsistent regarding the association between maternal obesity and Apgar score or cord pH in humans. The aim of this study was to investigate the association between maternal pre-pregnancy and pregnancy body mass index (BMI) and infant Apgar score or cord pH. We conducted a systematic review of studies published in English before 20 August 2015 using PubMed, EMBASE, and Cochrane Library. Eleven cohort studies with a total of 2,586,265 participants finally met our inclusion criteria. Pooled results revealed the following factors associated with Apgar score <7 at 5 minutes: overweight (odds ratio [OR] 1.13; 95% confidence interval [CI], 1.08-1.20), obese (OR 1.40; 95% CI, 1.27-1.54), and very obese (OR 1.71; 95% CI, 1.55-1.89). The pooled analysis also revealed that maternal overweight or obesity increased the risk for Apgar score <7 at 1 minute. There was no association between maternal BMI and neonatal cord pH. Thus, this study suggests that maternal overweight and obesity affect baby's condition immediately after birth in general. More studies are needed to confirm these results and detect the influence of variables across studies.