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

Abstract

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.

Figure 1. Forest plot of pooled analyses of maternal BMI categories and an Apgar score <7 at 1 minute.

Maternal overweight, obesity and very obesity by BMI categories was significantly associated with Apgar score <7. Maternal underweight categories showed nonsignificant trends toward increased an Apgar score <7. Note that obesity group compared with non-obese controls (BMI < 30) in the Minsart et al. study. In others studies, ORs are for each category as compared with the “normal weight” category (BMI 18–25).

Figure 2. Forest plot of pooled analyses of maternal BMI categories and an Apgar score <3 at 5 minute.

Maternal obesity by BMI categories was significantly associated with Apgar score <3. Maternal underweight, overweight, and very obesity categories showed nonsignificant trends toward increased an Apgar score <3. Note that ORs are for each category as compared with different reference category (Chen et al., BMI < 25; Magann et al., BMI 18–25; Persson et al., BMI 18.5–34.9).

Figure 3. Forest plot of pooled analyses of maternal BMI categories and an Apgar score <7 at 5 minute.

Maternal overweight, obesity and very obesity by BMI categories was significantly associated with Apgar score <7. Maternal underweight categories showed nonsignificant trends toward increased an Apgar score <7. Note that reference category was BMI < 25 in Chen et al. study. In other studies, ORs are for each category as compared with the “normal weight” category (BMI 18–25).

Figure 4. Forest plot of pooled analyses of maternal BMI categories and cord pH < 7.1.

Maternal BMI in different categories showed nonsignificant associations with cord pH < 7.1. Note that ORs are for each category as compared with the “normal weight” category (BMI 18–25).