Pregnancy outcomes at maternal age over 45 years: a systematic review and meta-analysis

This study aimed to identify trends in pregnancy outcomes, especially delivery mode, among pregnant patients older than 45 years.

A literature search was performed using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for studies published between January 1, 2010, and June 30, 2022.

The primary outcomes were cesarean delivery and assisted delivery. The secondary outcomes were preeclampsia, gestational diabetes mellitus, placenta previa, placental abruption, postpartum hemorrhage, and preterm birth. The inclusion criteria were studies examining the relationship between older age pregnancy and pregnancy outcomes, studies that compared pregnancy outcomes at maternal age ≥45 years and <45 years, and at least one of the primary and secondary pregnancy outcomes were included.

Study screening was performed after duplicates were identified and removed. The quality of each study and publication bias were assessed. Forest plots and I² statistics were calculated for each study outcome for each group. The main analysis was a random-effects analysis. The inverse variance method was used to integrate the results if studies had an adjusted analysis.

Among 4209 studies initially retrieved, 24 were included in this review. All studies were retrospective, observational studies. Pregnant patients aged ≥45 years had a significantly higher cesarean delivery rate (odds ratio, 2.87; 95% confidence interval, 2.50-3.30; I²=97%) than those aged <45 years. However, the emergency cesarean delivery rate was lower in older pregnant patients (odds ratio, 0.61; 95% confidence interval, 0.47-0.79; I²=79%). Pregnancy in older individuals was associated with a lower assisted delivery rate than pregnancy in younger individuals (odds ratio, 0.85; 95% confidence interval, 0.75-0.97; I²=48%). Preeclampsia, gestational diabetes mellitus, placenta previa, placental abruption, postpartum hemorrhage, and preterm birth were more likely to occur in pregnant patients aged ≥45 years than in those aged <45 years. Adjusted pooled analyses showed trends similar to those in the unadjusted pooled analyses.

Adverse pregnancy outcomes, typically cesarean delivery, were more likely to occur in older (≥45 years) pregnant patients than in younger pregnant patients. However, the assisted delivery rate was lower in older pregnant patients.