Low Quality Eggs of Obese Women Affects IVF Treatment

A healthy body with a healthy weight can improve the chances of becoming pregnant through In vitro fertilization (IVF) treatment. Highlighting the point, scientists have discovered the mechanism that reduces the success of IVF treatment in severely obese women and take preventive steps.

Dr. Catherine Racowsky and colleagues from Brigham and Women's Hospital (BMH) analyzed 276 mature human eggs that failed to fertilize.  Of the total number of eggs, 105 belonged to severely obese women, with a high body mass index (BMI) - between 35.0 and 50.1 kg/m2.

The quality of the egg is the most important factor that determines the success of the IVF treatment. Having a high BMI can negatively affect the egg quality.

"This study is the first to shed light on how BMI might adversely affect egg quality in women," Dr. Racowsky, said in a news release. "These observations provide novel insight into a possible cause for the reduced likelihood of success with IVF in severely obese women."

An egg mature with one spindle and a set of organized chromosomes are essential for a successful fertilization and favorable embryo development.  However, this specific egg structure was found missing in severely obese women- eggs with multiple spindles and disorganized chromosomes.

Researchers found a significant number of the severely obese women having two spindles (60 percent) and disorganized chromosomes (30 percent) compared with the normal BMI group (35 percent and 9 percent respectively).

As the study was particularly based on eggs stimulated through IVF, the investigators recommend further studies to re-assure the findings.

"More research is needed to determine what is causing the spindle abnormalities and disorganized chromosomes," said Racowsky.

Findings have been published in the journal Human Reproduction.

The findings come at a time when one third of women of childbearing age in the United States are obese. According to health experts, a body mass index (BMI) of 19 to 25 is the ideal weight for conceiving.