Overweight and obese couples who are trying to start a family may want to consider losing weight first. Those extra pounds could lengthen the time it takes them to conceive a child.
Doctoral student Cecilia Ramlau-Hansen and her colleagues at Aarhus University Hospital in Denmark used data on nearly 48,000 births to study how the couples' weights were related to the time it took them to conceive. Cases in which the mother had a medical condition that might contribute to either obesity or fertility problems were excluded.
Couples who took longer than 12 months to conceive were considered "subfertile."
"If both partners were obese, there was a three-fold increase in risk of subfertility," says Ramlau-Hansen, who is currently a visiting scholar at the University of California at Los Angeles School of Public Health's department of epidemiology.
"Women's weight was a bit more serious," Ramlau-Hansen says, but she notes that men's weight was also a factor.
However, Ramlau-Hansen notes that all couples in the study eventually conceived. "We don't think it can lead to sterility," she says. "It just takes longer."
A further analysis of more than 2,300 couples who had at least two births showed women who experienced post-pregnancy weight gain took longer to conceive their second child, while overweight or obese women who lost weight before their second pregnancy took less time to conceive.
Ramlau-Hansen says she would consider advising couples who are overweight or obese, and who wish to conceive, to try to lose weight.
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