The sperm from older men has been found wanting in new study from Columbia University's Mailman School of Public Health. The researchers found that older fathers are linked with increased rates of spontaneous abortion (miscarriage), and the older the man, the more the risk of miscarriage. Interestingly, the new finding is completely independent of the mother's age. "There has been a tremendous amount of research on women, and how their characteristics affect pregnancy outcomes. However, scientists seem to have forgotten that men are equal partners in reproduction. Our group has focused on men's influence on the health of their offspring, and we have made some fascinating discoveries," said Karine Kleinhaus, first author of the study. "This study shows how a man's age affects the likelihood of miscarriage."
The research follows on from earlier studies at Columbia that found that older men's sperm was associated with schizophrenia in offspring. "This is not as surprising as it may sound at first, as it was already shown by other researchers that older men have more abnormalities in their sperm, and that their children are more susceptible to certain birth defects," observed Dr. Klienhaus.
In light of these facts, the American Society for Reproductive Medicine has set an upper age limit of 40 for semen donors because of the increased risk of genetic abnormalities with older fathers.
The new study focused exclusively on spontaneous abortion as the outcome, and took into account variables such as maternal diabetes, history of prior spontaneous and induced abortions, maternal smoking and socioeconomic status. The results indicated that as the male partner ages, there is a steady increase in rate of miscarriage. Women with partners aged 35 or older had nearly three times as many miscarriages as compared with women conceiving with men younger than 25 years of age.
"As child bearing is increasingly delayed in Western societies, this study provides important information for people who are planning their families," concluded Dr. Kleinhaus. "The study also adds to a growing understanding of how men's age, health, and occupations can affect their partner's pregnancies and the offspring's future development."
Based on material from Columbia University's Mailman School of Public Health
