Associations between Advanced Paternal Age and Adverse Reproductive Outcomes in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b).

The association between paternal age and adverse pregnancy outcomes (APOs) has not been well studied. We sought to determine whether advanced paternal age (APA) is associated with adverse maternal or neonatal outcomes.Secondary analysis of 8,863 pregnancies from the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-Be (nuMoM2b) prospective cohort in which both maternal and paternal age at conception were known. APA was defined as age ≥ 40 years and AMA was defined as age ≥ 35 years. Composite maternal and fetal/neonatal APO outcomes were adjudicated by experts using previously defined methods. Univariable and multivariable logistic regression models were used to estimate the associations between APA, AMA, and their combination (AMA and APA), with the outcomes of interest (APO, fetal/neonatal, and combined APO or fetal/neonatal outcomes). Multivariable analyses were adjusted for covariates identified a priori: self-reported race and ethnicity, education, body mass index, maternal medical conditions, assisted reproductive technology (ART), and maternal age in APA only models.APA in isolation was not significantly associated with maternal or fetal/neonatal adverse outcomes (adjusted odds ratio [aOR] = 1.08, 95% confidence interval [CI]: 0.89 - 1.32). In contrast, AMA pregnancies and pregnancies in which both parents were of advanced age were associated with significantly increased risk of maternal or fetal/neonatal adverse outcome (aOR = 1.37, 95% CI: 1.17 - 1.59, p < 0.001 and aOR = 1.60, 95% CI: 1.25 - 2.05, p < 0.001), respectively. Findings were similar when individuals who used assisted reproductive technology (ART) were excluded from analyses.In our study of nulliparous birthing people, in contrast to AMA pregnancies, APA alone was not significantly associated with a heightened risk of maternal or fetal/neonatal APOs. However, pregnancies from both AMA and APA individuals demonstrated a trend toward a higher risk of APOs compared with AMA pregnancies. Further research is needed to delineate the mechanism driving this finding. · There is an established association between older maternal age and increased risk of adverse pregnancy outcomes. Determining the influence of paternal age on pregnancy outcomes is of equal importance.. · Prior data are inconclusive on the association of APA and rates of miscarriage, fertilization rates, and aneuploidy, and to our knowledge, the associations with adverse pregnancy outcomes have not been previously examined.. · This study examines if APA (paternal age ≥ 40 years) is an independent risk factor for adverse pregnancy outcomes in a cohort of nulliparous birthing people..