Pregnancy May be Harder For Obese Couples, Study Shows

Couples wherein partners are obese could take from 55 to 59 percent longer to have pregnancy, compared to their non-obese counterparts, according to a study by researchers at the National Institutes of Health. The findings of this study are published in the online copy of Human Reproduction.

According to Rajeshwari Sundaram, Ph.D., a senior investigator in the Division of Intramural Population Health Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development, plenty of studies on fertility and body composition have been enthusiastic about the female partner, but their findings underscore the value of both partners. Their results additionally point out that fertility experts may want to take into account couples’ body compositions when counselling these patients.

The couples in this study had been a part of the Longitudinal Investigation of Fertility and the Environment (LIFE) study, which examined the relationship between fertility and exposure to environmental chemical compounds. 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 guys were over 18 years of age. Women kept journals to file their menstrual cycles, intercourse and the outcome of pregnant tests. The couples were followed up until pregnancy or for as much as one year of trying to conceive.

Researchers additionally calculated body mass index (BMI) for each participant, categorizing couples with obesity into two subgroups: obese class I (with a BMI from 30 to 34.9) and essentially the most obese group, obese type II (a BMI of 35 or higher).

The researchers compared the normal time to acquire pregnancy among couples within the non- obese group (84 males and 228 females) to that of the couples in the obese classification II group (75 males and 69 females).

The researchers then calculated the probability that a pair would achieve pregnancy by using a statistical measure referred to as the fecundability odds ratio (FOR). The measure estimates couples’ probability of pregnancy each menstrual cycle while at the same time attempting for pregnancy, relative to their BMIs.

The researchers located that the class II couples took for much longer to attain pregnancy than couples not struggling with obesity. Couples in the non-overweight group had a FOR of 1. , obese classification II couples had a FOR of .45 — indicating that they took 55 percent longer to achieve pregnancy than their normal weight counterparts. When the researchers took into consideration other explanations identified to have an impact on fertility — akin to age, smoking status, physical activity and cholesterol levels — the ratio for obese class II couples dropped to .41, or a 59 percent longer time to get pregnant.

The authors noted that prior reports have centered largely on just the feminine partner’s BMI or self-reported height and weight. However, findings much like the current study have been done  among couples who are undergoing assisted reproduction. The current study centers on couples within the general population, not those taking medication for infertility.