When it comes to getting pregnant, doctors and fertility specialists have traditionally looked at a woman’s health as the main contributing factor for complications related to conception.
Now, a new study suggests that couples in which both partners are obese may take from 55 to 59 percent longer to achieve pregnancy compared to their nonobese counterparts according to a study by researchers at the National Institutes of Health.
The study, released on Feb. 3, 2017, focused on couples in the general population, not those undergoing treatment for infertility. The study enrolled 501 couples from Michigan and Texas from 2005 to 2009. The women ranged from 18 to 44 years of age, and the men were over 18 years old and were followed until pregnancy or for up to one year of trying to conceive.
During the study, women were asked to keep journals and record their menstrual cycles, intercourse and results of home pregnancy tests. Researchers calculated body mass index for each participant and placed them in two separate groups: class I (BMI of 30 to 34.9) and class II (BMI of 35 or greater). A BMI of greater than 30 is considered obese.
The researchers compared the average time to achieve pregnancy among the two groups — class II had 69 women and 75 men, while class I had 228 women and 84 men — by calculating the probability a couple would achieve pregnancy using a statistical measure called the fecundability odds ratio. The measure estimates couples’ probability of pregnancy each menstrual cycle while trying for pregnancy relative to their BMIs.
The study found that the class II couples took significantly longer to achieve pregnancy (55 percent longer) than the nonobese class I group. And when researchers took into account other factors known to influence fertility — such as age, smoking status, physical activity level and cholesterol level — they found that it took the class II group 59 percent longer to achieve pregnancy.
The authors concluded that couples’ obesity may reduce fertility chances, and therefore, it is advisable that the specialists discuss weight issues during counseling sessions.
“Our results indicate that fertility specialists may want to consider couples’ body compositions when counseling patients,” noted senior researcher, said Rajeshwari Sundaram, Ph.D.