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 > or =11 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 > or =8 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 hyperstimulation 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. 31.4% and 4.9% vs. 4.1%, respectively).

CONCLUSION(S): The addition of E(2)/follicle criteria to ultrasound monitoring of IVF cycles in normal responders seldom changes the timing of hCG, and does not increase pregnancy rates or the risk of OHSS.