Perinatal outcomes in pregnant women over 45 years old: Singleton or multiple pregnancy?

Introduction

Advanced maternal age is associated with a greater number of obstetric complications and adverse perinatal outcomes. It is increasingly common to find pregnant women over 45 years of age and even over 50. There are few studies that evaluate perinatal outcomes at extreme ages, over 45 years of age. Therefore, the objective of this study is to explore perinatal outcomes in the pregnancies of women over 45, as well as to compare twin and singleton pregnancies in this population.

Material and methods

An observational retrospective case–control study was carried in the Obstetrics and Gynecology Department of University Hospital La Paz (Madrid, Spain) between January 2017 and June 2023. All twin pregnancies of mother over 45 at the time of delivery as cases (n = 22) and 3 controls for each case (n = 65) were included. Perinatal outcomes were assessed and compared between singleton pregnancies and twins.

Results

The frequency of preeclampsia was statistically higher in the twin group (27.3% vs 7.7%; p = 0.017) (OR 4.5 (1.21–16.65)). Cesarean section was significant more frequent in the twin group (90.9% vs 49.2%; p = 0.001) (OR 10.31 (2.23–47.75)). In twins, prematurity rate (68.2% vs 17.2%; p < 0.001) and admission to neonatal ICU (63.6% vs 14.5%; p < 0.001) were increased. No differences were found in gestational diabetes, pregnancy-induced hypertension, small for gestational age, Apgar test < 7 at 5 min or in the pH < 7.10 in cord blood at birth.

Conclusions

Advanced maternal age is an independent risk factor for adverse perinatal outcomes and obstetric complications, independently of the number of fetuses, especially at extreme fertile ages above 45 years. In the case of twin gestations, risks inherent to twins also increase, such as prematurity, admission to the NICU and CS.