Effects of maternal obesity, excessive gestational weight gain and fetal macrosomia on the frequency of cesarean deliveries among migrant and non-migrant women - a prospective study.

Background Maternal obesity, excessive gestational weight gain and fetal macrosomia may affect the health of the mother and the newborn, and are associated with cesarean delivery. Pregnant women with a migration background have a higher risk of obesity but nevertheless a lower frequency of cesarean deliveries than women from the majority population. This study assesses which of these factors most influence the risk of a cesarean delivery and whether their prevalence can explain the lower cesarean rates in migrant women. Methods A total of 2256 migrant women and 2241 non-immigrant women subsequently delivering in three hospitals of Berlin/Germany participated. Multivariate logistic regression analysis was conducted to assess the effects of obesity, excessive gestational weight gain and macrosomia on cesarean delivery. Standardized coefficients (STB) were used to rank the predictors. Results Obesity was more frequent in immigrant than among non-immigrant women. The mean gestational weight gain was independent of migration status. The frequency of macrosomia increased with maternal weight. Obesity and excessive gestational weight gain were the most important predictors of cesarean besides older age; fetal macrosomia played a much smaller role. Despite similar distributions of the three risk factors, the frequency of cesarean deliveries was lower in migrant than in non-immigrant women. Conclusion The presence of obesity and/or excessive gestational weight gain is associated with an increased risk of a cesarean delivery; fetal macrosomia does not increase the risk when obesity and weight gain are considered. The distribution of these risk factors is similar in migrant and non-immigrant women, so they cannot explain the lower frequency of cesarean deliveries in migrant women.