Encourage healthy BMI in patients before IVF: study of 5,800 IVF cycles shows a trend toward decreasing success rates with increasing BMIs.(Gynecology)

PHILADELPHIA -- Patients considering in vitro fertilization should be encouraged to aim for a healthy body mass index before they start treatment, results of a large retrospective study suggest.

"There was a trend toward decreasing success rates with increasing BMIs," reported lead investigator David Ryley, M.D., of Beth Israel Deaconess Medical Center, Boston, and Boston IVF, a private fertility clinic.

The study reviewed more than 5,800 fresh, non-donor in vitro fertilization (IVF) cycles at Boston IVF in which the patient's BMI had been recorded, he reported at the annual meeting of the American Society for Reproductive Medicine.

Patients were divided into five groups according to BMI: under 20 kg/[m.sup.2], 20-24.9 kg/[m.sup.2], 25-29.9 kg/[m.sup.2], 30-34.9 kg/[m.sup.2], and more than 35 kg/[m.sup.2]. Women with a BMI of more than 40 kg/[m.sup.2] are not allowed to undergo IVF at the center, he said.

There was no difference between the groups with respect to the number of mature follicles, number of oocytes retrieved, number of mature oocytes, the number of cycles per patient, and the number of embryos transferred. Still, patients in the highest BMI category had a significantly lower implantation rate and clinical pregnancy rate, compared with the other BMI groups.

Although the clinical pregnancy rate ranged from about 27% to almost 33% in the lower BMI categories, it was not quite 22% in the highest BMI category.

Similarly, the implantation rate ranged from 18% to 20% in the lower BMI ...