Association of Paternal Age Alone and Combined with Maternal Age with Perinatal Outcomes: A Prospective Multicenter Cohort Study in China.

Maternal and paternal age at birth is increasing globally. Maternal age may affect perinatal outcomes, but the effect of paternal age and its joint effect with maternal age are not well established. This prospective, multicenter, cohort analysis used data from the University Hospital Advanced Age Pregnant Cohort Study in China from 2016 to 2021, to investigate the separate association of paternal age and joint association of paternal and maternal age with adverse perinatal outcomes. Of 16,114 singleton deliveries, mean paternal and maternal age (± SD) was 38.0 ± 5.3 years and 36.0 ± 4.1 years. In unadjusted analyses, older paternal age was associated with increased risks of gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy, preeclampsia, placenta accreta spectrum disorders, placenta previa, cesarean delivery (CD), and postpartum hemorrhage, preterm birth (PTB), large-for-gestational-age, macrosomia, and congenital anomaly, except for small-for-gestational-age. In multivariable analyses, the associations turned to null for most outcomes, and attenuated but still significant for GDM, CD, PTB, and macrosomia. As compare to paternal age of < 30 years, the risks in older paternal age groups increased by 31-45% for GDM, 17-33% for CD, 32-36% for PTB, and 28-31% for macrosomia. The predicted probabilities of GDM, placenta previa, and CD increased rapidly with paternal age up to thresholds of 36.4-40.3 years, and then plateaued or decelerated. The risks of GDM, CD, and PTB were much greater for pregnancies with younger paternal and older maternal age, despite no statistical interaction between the associations related to paternal and maternal age. Our findings support the advocation that paternal age, besides maternal age, should be considered during preconception counseling.Trial Registration NCT03220750, Registered July 18, 2017-Retrospectively registered, https://classic.clinicaltrials.gov/ct2/show/NCT03220750 .