The risk of intrapartum cesarean delivery in advanced maternal age

Abstract

Objective: We aimed to investigate the association of advanced maternal age with intrapartum cesarean delivery and to assess its risk factors and perinatal outcomes.

Study design: A retrospective cohort study of all women with singleton pregnancies who attempted a trial of labor (≥24 + 0 weeks of gestation) in a single center (2011-2017). The study population was stratified by parity (nulliparous or multiparous) and further sub-categorized into three cohorts: (1) women <35 years at birth (reference group), (2) women aged 35-40 years, and (3) women >40 years. Labor and delivery characteristics and neonatal outcomes were compared.

Results: Overall, 55,089 women were included: 39, 192 (71.1%) were under 35 years old, 15,90712,892 (28.923.4%) were 35-40 y and 3,015 (5.5%) were >40 y. For nulliparas, the rate of intrapartum Cesarean deliveries increased with maternal age and approached 25.3% in those >40 y as compared to 8.9% for those <35 y. The positive association between Cesarean section rates and maternal age extends beyond nulliparas and is also seen in multiparas, although to a smaller degree. After adjusting for confounders, maternal age was significantly and independently associated with intrapartum cesarean delivery in a dose-dependent manner in nulliparous women, [adjusted Odd Ratio (aOR) 1.56 (95% Confidence Interval (CI) 1.39-1.76) and 2.53 (2.07-3.09)] among women aged 35-40 y and >40 y, respectively. Maternal age was not significantly associated with adverse neonatal outcome.

Conclusion: Advanced maternal age is an independent risk factor for intrapartum Cesarean delivery. Yet, the majority of older gravidae who attempt a trial of labor, even if nulliparous, deliver vaginally without an increase in adverse neonatal outcome.

Keywords: Advance maternal age; cesarean delivery; neonatal outcome; pregnancy outcome.