Preovulatory serum estradiol-17 beta values and ultrasound scans in 17 pregnancies which followed in vitro fertilization and embryo transfer after treatment with clomiphene and hCG.

17 patients whom we treated with clomiphene and hCG became pregnant after in vitro fertilization (IVF) and embryo transfer (ET). We now report on our experience with preovulatory estradiol 17 beta values and ultrasonography in determining the time of hCG administration in these patients. The mean estradiol value just before the hCG injection was 329 +/- 75 pg/ml/follicle. The mean follicle diameter on ultrasound was 23.4 +/- 1.5 mm on the same day. In four cases, we only used estradiol values and in one case only ultrasound for the timing of the hCG injection. Both methods of monitoring follicular growth are discussed.