Assessment of uterine artery blood flow on the day of human chorionic gonadotropin administration by transvaginal color Doppler ultrasound in an in vitro fertilization program

Objective: To assess whether measurement of uterine artery blood flow impedance (the pulsatility index) as determined by transvaginal color Doppler ultrasound on the day of hCG administration in patients undergoing IVF can predict pregnancy and implantation rates. Design: Prospective observational study of women undergoing IVF. Setting: A tertiary referral center for assisted reproduction. Patients: One hundred thirty-five patients undergoing 139 IVF cycles. Intervention: Transvaginal color Doppler assessment of uterine artery pulsatility index on the day of administration of hCG. Main Outcome Measures: Mean pulsatility index of the left and right uterine arteries, pregnancy rate, and embryo implantation rate. Results: The patients were grouped into pregnant and nonpregnant groups and according to whether the pulsatility index was low (1.00 to 1.99), medium (2.00 to 2.99), or high (greater than or equal to 3.00). The pregnancy rates were 13.8%, 34.7%, and 14.3% for the low, medium, and high pulsatility index groups, respectively, and were not significantly different. The implantation rates for the same groups were 10.7%, 16.3%, and 5.4%, respectively. The implantation rate for all the patients with pulsatility index <3.00 (and especially 2.00 to 2.99) was significantly higher than the high pulsatility index group. Conclusions: The study suggests that the measurement of uterine artery pulsatility index on the day of hCG predicts subsequent implantation rates. It may allow the administration of hCG to be deferred until uterine artery pulsatility index falls to <3.00, which may result in improved implantation rates.