Incidence of obese parturients and the outcomes of their pregnancies: A nationwide register study in Finland.

Objectives: We analyzed the incidence of obese and severely obese parturients and the impact of maternal obesity on mode of delivery, perinatal and neonatal mortality, and neonatal health.

Study Design: We 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/m), obese (BMI 30 - 39.9 kg/m), and morbidly obese (BMI 40 kg/m or more). The yearly incidence of obese and severely obese parturients per 10000 births was calculated. Logistic regression was used to calculate adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Results: 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 (aOR 1.63 CI 1.61 - 1.66 and 2.33 CI: 2.23 - 2.44). Neonates born to morbidly obese parturients had an increased need for intensive care unit treatment (aOR 2.21 CI: 2.10 - 2.32), higher perinatal mortality (aOR 1.65 CI: 1.28 - 2.14), and higher neonatal mortality (aOR 1.68 CI: 1.04 - 2.72). The need for neonatal intensive care (aOR 1.50 CI: 1.47 - 1.53), perinatal mortality (aOR 1.25 CI: 1.13 - 1.39), and neonatal mortality (aOR 1.33 CI: 1.09 - 1.62) increased also among obese parturients.

Conclusions: We report a worrying increase in obese and morbidly obese parturients. Neonates born to these parturients were more likely delivered by cesarean sections and had higher rates of perinatal and neonatal mortality, and intensive care unit treatment. This highlights the importance of preventing obesity among fertile-aged females.