Neonates born to obese parturients at higher risk of mortality and ICU treatment: Study

Study included all singleton births from the medical birth register of Finland from 2004 to 2018 (n = 792 437). Maternal body mass index (BMI) was categorized into three classes: non-obese (BMI < 30 kg/m2 ), obese (BMI 30 – 39.9 kg/m2 ), and morbidly obese (BMI 40 kg/m2 or more). The yearly incidence of obese and severely obese parturients per 10 000 births was calculated. Logistic regression was used to calculate adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Between 2004 and 2018, the incidence of obese and morbidly obese parturients increased by 44% and 103%, respectively. Cesarean section rates were 23.6% and 30%, respectively. Neonates born to morbidly obese parturients had an increased need for intensive care unit treatment, higher perinatal mortality, and higher neonatal mortality. The need for neonatal intensive care, perinatal mortality and neonatal mortality increased also among obese parturients.

Study found an alarming increase in the incidence of obese and especially morbidly obese parturients. Morbidly obese parturients had twice as many elective and non-elective CS compared to non-obese parturients. Furthermore, perinatal, and neonatal mortality and the need for intensive care were more common among neonates born to obese and morbidly obese parturients. Stratified analysis by GDM showed that obesity was an independent factor for worse neonatal outcomes. Furthermore, stratified analysis by mode of delivery showed that obese women with spontaneous vaginal or vacuum-assisted delivery had the highest odds of neonatal mortality and that the risk of neonatal intensive care was higher with vaginal deliveries among both obese and morbidly obese than among non-obese women.

The increase of morbidly obese parturients is especially worrying as these women have been reported to have the highest rate of acute pregnancy complications, and complication risks in subsequent pregnancies are also increased. Furthermore, infertility is more common in obese women. Acute complications associated with obesity include preeclampsia, macrosomia, preterm birth, difficulties in labor induction, and prolonged labor. These factors may explain the high rate of labor induction and at least some of the increased risk of CS among morbidly obese parturients (a two-fold increase in the rates of elective and urgent CS, though emergency CS rates were in line with the other groups)

As the incidence of obese and morbidly obese parturients continues to rise, it is important to understand the negative effects this has on neonatal outcomes. Obese and morbidly obese women are more likely to deliver by elective and non-elective CS; their neonates require more intensive care unit treatment and have higher rates of mortality. The rates of adverse perinatal outcomes are higher in vaginal deliveries. This highlights the need for further discussion and prospective research on the best pregnancy follow-up and delivery method.

Source: I. Kuitunen et al.; European Journal of Obstetrics & Gynecology and Reproductive Biology 274 (2022) 62–67