Delivery rates among patients of advanced maternal age (AMA) are increasing. Prior studies have shown that AMA is associated with increased pregnancy risks and adverse outcomes. This study’s objective was to evaluate whether AMA is associated with an increase in obstetric anal sphincter injury (OASIS) rates among patients who undergo forceps-assisted vaginal deliveries (FAVDs).
This was an IRB-approved, retrospective cohort study of singleton gestations with FAVD at a single institution between 2017 and 2021. Primary outcome was rate of OASIS among patients with and without AMA. Secondary outcomes included quantitative blood loss (QBL), neonatal composite of subgaleal and cephalohematoma (adverse neonatal composite), and neonatal intensive care unit (NICU) admission. Quantitative blood loss was assessed using Mann-Whitney U test. Remaining outcomes were assessed using multivariate logistic regression models while adjusting for provider clustering and confounding patient characteristics including episiotomy and birth weight.
Nine hundred eighty-three records were included, 704 non-AMA and 279 AMA. Patients of AMA were more likely to be Caucasian and were less likely to be Hispanic, nulliparous, experience spontaneous labor, and undergo episiotomy. Patients of AMA did not demonstrate increased odds of OASIS compared to non-AMA patients (odds ratio [OR] 1.21 [0.78, 1.89]). When age was assessed continuously, there was no association between increasing age and rates of OASIS (OR 1.02 [0.98, 1.06]). There was no statistically significant difference in QBL among the two groups (357.0 versus 350.0 cc, P=.20), NICU admission or adverse neonatal composite.
Advanced maternal age does not appear to be a risk factor for OASIS or other adverse outcomes in patients undergoing FAVD.