When It Comes to Conception, Don't Ignore Dad's Biological Clock

Over the past 40 years, the average paternal age in the U.S. has risen. To examine the effects of this trend on perinatal outcomes, investigators conducted a population-based, retrospective cohort study using data from the National Vital Statistics System for >40 million live births in the U.S. between 2007 and 2016.

After controlling for maternal age, race, education, smoking status, and number of prenatal visits, men older than 35 compared with those aged 25 to 35 had higher odds of fathering infants born premature and of low birth weight. Infants fathered by men older than 55 were the most likely to require assisted ventilation and admission to a neonatal intensive care unit.