Researchers looked at data on 958,804 pregnancies between 2007 and 2016, and correlated that with information on the health of the parents for an average of about four years before conception. They evaluated the fathers’ health based on diagnoses of hypertension, high cholesterol, obesity or diabetes, plus the presence of other common chronic diseases.
Men who had one of these five health factors had a 10 percent increased risk for a partner’s pregnancy ending in loss. Two factors increased the risk by 15 percent, and three or more had a 19 percent increased risk. The age of the mother, along with other maternal and paternal health and behavioral factors, made little difference.
“We need to think about the father even pre-conception,” said Michael L. Eisenberg, an associate professor of urology at Stanford and senior author of the study. “We contribute half the DNA, so it makes sense that that would affect the trajectory of the pregnancy. I want to show that the father is important — fertility is a team sport.”