WEIGHT AND LOWER RATES OF LIVE BIRTHS AND EMBRYO IMPLANTATION
In an extremely large study done at IVI in Valencia 10,000 egg donation cycles were reviewed and the study demonstrated that increased weight decreases the receptivity of the embryo to implant in the womb and decreased the chance of having a live birth. This study was done in IVI in Spain and it was demonstrated that live birth rates were for overweight women were significantly reduced when compared for women with less weight or even slightly overweight.
It was also seen that the rates of embryo implantation dropped from 39% in normal weight, to 30% in increased weight. The investigators believed that the increase in weight does have a negative impact, even at the start of pregnancy, and continues until the end of pregnancy.
At present, it is not known how and why implantation rates are affected and how and why egg quality and embryo quality seems to decline.
There is some evidence coming up that the receptivity of the endometrium (lining of the womb) may also be affected in obese women and this may lead to a decline in fertility.
Thus, it is strongly recommended that the control of excess weight, including changes in lifestyle, should be mandatory for improving the chances of pregnancy in nature and also in assisted conception technology.