Extremes Of Weight Are Associated With Reduced Probability Of Achieving Pregnancy In Women Receiving Assisted Reproduction Treatment
The fertility of the moderate group was almost 60 percent higher than that of the very obese group, and the fertility of the underweight group was also significantly lower than that of the moderate group. When factors, such as age, number of embryos transferred and type of treatment were accounted for, the pregnancy rate among very obese women was half that of the moderate group.
Ways in which extremes of weight can affect fertility include menstrual disturbance and inability to ovulate, but these problems can be overcome through assisted reproduction treatment, say the authors. They suggest that other mechanisms, such as disturbance to the lining of the uterus, may cause reduced fertility.