Purpose: Pregnancy at advanced maternal age (AMA) has become more common. There has been concern regarding the adverse effect deferring pregnancy might have on pregnancy outcomes. We aimed to prospectively study the effect of AMA on placental pathology.
Methods: A prospective case-control study was performed in a single university center. Placental histopathology, maternal demographics, labor characteristics, and neonatal outcomes of pregnancies with AMA were collected and compared to matched controls. We defined AMA as maternal age > 35 years at delivery. In attempt to isolate the effect of maternal age, we excluded cases complicated by preterm birth, hypertensive disorders, diabetes mellitus, small for gestational age, and congenital/genetic anomalies.
Results: The study group included 110 AMA patients that were matched with controls. The groups did not differ in maternal demographics, but the AMA group had a higher rate of assisted reproductive technologies (ART) as compared to the control group (p < 0.001). Placentas in the AMA group were characterized by a higher rate of maternal vascular lesions (MVM) (39.1% vs. 24.5%, p = 0.003), but not fetal vascular malperfusion lesions (p = 0.576). In multivariable analysis maternal age was associated with placental MVM lesions independent of all other maternal demographics (aOR 1.18 95% CI 1.06-3.17). Neonatal outcomes did not significantly differ between the groups.
Conclusions: After excluding all background morbidities-AMA was associated with a higher rate of placental MVM lesions vs. controls. These findings suggest an independent effect of AMA on placental function. Large prospective trials are needed to study the clinical importance of these findings.
Keywords: Advanced maternal age; Maternal vascular malperfusion lesions; Pathology; Placenta; Uterine environment.