Effect of maternal age on maternal and perinatal outcomes including cesarean delivery following induction of labor in uncomplicated elderly primigravidae

Age above 35 years at the time of birth is generally referred to as advanced maternal age (AMA), and it could be a risk factor for various complications besides genetic changes in the fetus. The primary outcome of this study was to determine if AMA is associated with emergent cesarean delivery (CD) following induction of labor (IOL). The secondary outcomes were a composite of adverse maternal and perinatal outcomes following IOL. This retrospective observational study included women with singleton, live-born, cephalic, non-anomalous pregnancies undergoing IOL from 38 0/7 to 41 6/7 weeks of gestation. Mode of delivery and other maternal and neonatal outcomes were compared between women aged ≥35 (AMA) and <35 years. Multivariate logistic regression analyses were performed. A total of 307 nulliparous women underwent IOL (≥35 years n = 73, 23.8%; <35 years n = 234, 76.2%) and among them, 252 (82.1%) delivered vaginally. The rate of CD was significantly higher in women of AMA (31.5% vs 13.7%, P = .001). Multivariable analysis showed that AMA was independently associated with CD (odds ratio 3.04, 95% confidence interval 1.55–5.96, P = .001). The rate of instrumental deliveries was higher in the AMA group (19.6% vs 8.2%, P = .043) and hemoglobin decrease during delivery was similar between the 2 groups (1.90 ± 1.25 vs 2.02 ± 1.27 mg/dL, all P > .05). Regarding neonatal outcomes, there was no difference between the 2 groups in the neonatal intensive care unit admission rate and Apgar score <7 at 5 minutes (30.3% vs 30.1% and 6.0% vs 8.2%, respectively, all P > .05). Neonatal intubation rate and severe respiratory problems were non-significantly higher in AMA (3.8% vs 2.7% and 3.4% vs 1.4%, respectively, all P > .05). AMA was associated with an approximately three-fold increased likelihood of birth by CD and operative vaginal delivery in uncomplicated nulliparous women following IOL. However, we found no evidence that IOL in primigravid women of AMA increases adverse maternal and perinatal outcomes as compared with women aged <35 years except the high prevalence of CD and operative vaginal delivery.