Obese Couples Risk Lower Fertility
Study Shows Weight of Both Partners May Affect Conception
Weight Loss Reduced Time to Conception continued...
Obese women had a 78% greater risk of being sub-fertile than normal-weight women, and obese men had a 49% increased risk for sub-fertility than normal-weight men.
The risk of taking more than a year to achieve a pregnancy was 2.74 times higher when both partners were obese than for a normal-weight couple.
The researchers further examined 2,374 couples who had more than one pregnancy. When they converted the length of time that it took the women to get pregnant into days, they concluded that for overweight or obese women, every 2.2 pounds of weight loss reduced the time to conception by an average of 5.5 days.
Heavier Men Have Less Sex
The suggestion that weight loss seems to improve fertility for both women and, to a lesser extent, men has important potential public health implications, says epidemiologist Donna Baird, PhD, of the National Institute of Environmental Health Sciences (NIEHS).
Baird co-authored a 2006 NIEHS study that linked obesity to infertility in men. The researchers concluded that a 3-unit increase in BMI increased the risk of infertility by about 10%.
At least one other study has linked obesity in men to a decline in sperm quality, but Baird says more research is needed to confirm the association between body weight and infertility in men.
She adds that the decline in fertility among overweight and obese men may have more to do with sexual function than sperm quality.
“There are a lot of gaps in what we know,” she tells WebMD. “We didn’t have data on the frequency of sexual intercourse among men, and we know that obesity can certainly impact sexual function. Low libido and erectile dysfunction, for example, are much more common in obese men.”