Peripartum and Perinatal Outcomes in Pregnant Women with Elevated Preconceptional Body Mass Index in a Maternity Hospital (Care Level IV).

Introduction: Preconception obesity is a risk factor for pregnancy and delivery, which is why giving birth in a perinatal center (care levels I and II) is recommended. There are currently no studies which have investigated the birth outcomes of obese patients based on the care level of the maternity hospital. This study aims to assess the effect of a higher body mass index prior to conception on maternal and fetal outcomes in a maternity hospital (care level IV).

Patients and methods: A total of 5616 pregnant women who gave birth between 2016 and 2023 were investigated in this retrospective cohort study, after taking the inclusion and exclusion criteria into account. Primary outcome parameter of this study was the transfer of the neonate to a neonatal intensive care unit. Other target parameters were the need to induce labor, delivery mode, Apgar score and pH value, and the incidence of complications (shoulder dystocia, higher-degree perineal tears, or peripartum hemorrhage).

Results: Overweight and obesity were associated with a higher rate of hypertensive disorders of pregnancy and gestational diabetes and were accompanied by higher rates of induction of labor and elective and secondary caesarean sections. Maternal outcome parameters such as intrapartum fever, preterm placental abruption, uterine rupture, higher-degree birth injuries and peripartum hemorrhage did not occur significantly more often in obese pregnant women. Fetal outcome parameters such as Apgar score and pH value did not differ from those reported for normal-weight pregnant women. Multivariate regression analysis showed a high risk of transfer to a neonatal intensive care unit (OR = 1.97; p = 0.035) for neonates born to women in obesity class II (BMI 35-39.9 kg/m ² ), women with gestational diabetes (OR = 1.71; p = 0.033), and nulliparous women (OR = 1.59; p = 0.005).

Conclusion: Obesity class II is associated with a slightly higher risk of transfer of the neonate to a pediatric intensive care unit but is not associated with worse Apgar scores or pH values. Pregnant women with a body mass index between 35 and 40 kg/m ² should be informed of this and should consider giving birth in a facility with a neonatal department (care level I-III).