Influence of Body Mass Index, BMI on IVF Outcome

Materials and Methods

• This was a retrospective study of 1,150 IVF stimulation cycles in women under the age of 40 using their own eggs from January 2003 through July 2007.
  
  
• The cases were clustered into two groups according to their BMI of under 30 or over 30.


• Patients that had 4 or more good quality embryos on day 3 were cultured to day 5 for transfer.


• Assessments were made for the average antral follicle count, number of eggs, rates of implantation, clinical pregnancy, live birth, miscarriage, day 3 and day 5 embryo transfer, and IVF cycle cancellation.


• Statistical analysis was performed by the t-test and Fishers exact test when appropriate.

Summary

• Women with a higher BMI had significantly more antral follicles and eggs retrieved and a higher likelihood of having a day 5 transfer.


• However, there was no difference between the BMI groups for clinical pregnancy, miscarriage, or live birth rates.


• It is possible that the higher number of eggs and higher chance for a day 5 transfer is due to a higher incidence of polycystic ovarian syndrome, PCOS, in women with�  BMI > 30.


• Overall in our program, day 5 pregnancy and live birth rates are significantly higher as compared to day 3 transfers.


• Therefore, because there was a higher rate of day 5 transfer in the obese group but not a corresponding increase in implantation, clinical pregnancy, or live birth rates we speculate that either embryo viability or uterine receptivity may be compromised in obese women.


• Because the embryo transfer procedure can be more difficult in obese women, there could also be a loss of efficiency related to the difficulty of the transfer process.