Monitoring of in vitro fertilization-embryo transfer cycles by ultrasound versus by ultrasound and hormonal levels: a prospective, multicenter, randomized study

Objective: To determine whether cycle monitoring using both serum E-2 and ultrasound findings yields superior clinical pregnancy rates during IVF-embryo transfer (ET) compared to monitoring with ultrasound alone. Design: Prospective, randomized, multicenter, patient-blinded study. Setting: Four assisted conception units in the United Kingdom. Patient(s): Two hundred ninety-seven women believed to be normal responders undergoing IVF treatment. Intervention(s): Patients were randomly allocated on day 7 of stimulation to one of the two hCG administration criteria: [1] the E-2-to-follicle greater than or equal to11 mm ratio was between 250 and 500 pmol/L/follicle and at least 2 follicles reached a mean diameter of 18 mm or [2] at least 2 follicles reached a mean diameter of 18 mm and the endometrium thickness was greater than or equal to8 mm. Main Outcome Measure(s): Duration and cumulative dose of recombinant human FSH, total number of growing follicles, oocytes retrieved, number and quality of embryos, pregnancy rates, and ovarian hyper-stimulation syndrome (OHSS) rates. Result(s): Two hundred ninety-seven patients were randomized to one of the two criteria groups. Of these, 288 (97%) received urinary (u)-hCG (143 in group A and 145 in group B). One hundred three women in group A (72%) met both criteria for hCG administration. Pregnancy and OHSS rates were similar (34.3% vs. 3 1.4% and 4.9% vs. 4.1%, respectively). Conclusion(s): The addition of E-2/follicle criteria to ultrasound monitoring of lVF cycles in normal responders seldom changes the timing of hCG, and does not increase pregnancy rates or the risk of OHSS. (C) 2003 by American Society for Reproductive Medicine.