Relationship between Maternal Body Mass Index and Obstetric and Perinatal Complications

Over the past few decades, overweight and obesity have become a growing health problem of particular concern for women of reproductive age as obesity in pregnancy has been associated with increased risk of obstetric and neonatal complications. The objective of this study is to describe the incidence of obstetric and perinatal complications in relation to maternal body mass index (BMI) at the time prior to delivery within the Spanish Health System. For this purpose, a cross-sectional observational study was conducted aimed at women who have been mothers between 2013 and 2018 in Spain. Data were collected through an online survey of 42 items that was distributed through lactation associations and postpartum support groups. A total of 5871 women answered the survey, with a mean age of 33.9 years (SD = 4.26 years). In the data analysis, crude odds ratios (OR) and adjusted odds ratios (AOR) were calculated through a multivariate analysis. A linear relationship was observed between the highest BMI figures and the highest risk of cephalopelvic disproportion (AOR of 1.79 for obesity type III (95% CI: 1.06-3.02)), preeclampsia (AOR of 6.86 for obesity type III (3.01-15.40)), labor induction (AOR of 1.78 for obesity type III (95% CI: 1.16-2.74)), emergency C-section (AOR of 2.92 for obesity type III (95% CI: 1.68-5.08)), morbidity composite in childbirth (AOR of 3.64 for obesity type III (95% CI: 2.13-6.24)), and macrosomia (AOR of 6.06 for obesity type III (95% CI: 3.17-11.60)), as compared with women with normoweight. Women with a higher BMI are more likely to develop complications during childbirth and macrosomia.