Advanced Maternal Age and Pregnancy Outcomes in Oocyte Donation and Spontaneous Pregnancies: A Large Population-Based Cohort Study.

Background: Data regarding pregnancy and perinatal outcomes of oocyte donation (OD) recipients older than age 45 are limited. Materials and Methods: A total of 459,528 singleton pregnancies with 946 OD pregnancies and 458,582 spontaneous pregnancies were grouped according to maternal age ≥45 years and <45 years. Results: The mean maternal age of the OD recipients was 47.6 for patients >45 and 40.7 for patients ≤45 (p < 0.001). Among the spontaneous conceptions, the mean maternal age was 47.8 years for patients >45 and 31.1 for patients ≤45 (p < 0.001). Multivariable logistic regression for preterm birth (PTB) <37 weeks and for small gestational age (SGA) among the OD recipients demonstrated that age >45 is a protective factor for PTB <37 weeks (odds ratio [OR]: 0.6, 95% confidence interval [CI]: 0.4-0.9, p = 0.03) and for SGA (OR: 0.3, 95% CI: 0.1-0.7, p = 0.006, respectively). Among the spontaneous group, age >45 is a risk factor for PTB <37 weeks (OR: 3.2, 95% CI: 2.7-3.9, p < 0.001), PTB <34 weeks (OR: 4.7, 95% CI: 3.4-6.4, p < 0.001), SGA (OR: 1.6, 95% CI: 1.2-2.1, p < 0.001), and pregnancy-induced hypertension (OR: 3.1, 95% CI: 2.1-4.7, p < 0.001). Other obstetric complications were comparable between the age-groups of the oocyte recipients but were higher among patients >45 years who conceived spontaneously. Conclusions: As opposed to spontaneous pregnancies, OD pregnancies of recipients >45 are not associated with higher rates of obstetric or perinatal morbidity compared with younger recipients.