Simplification of the method of in vitro fertilization: Sonographic measurements of follicular diameter as the sole index of follicular maturity

Abstract

As a simplification of the in vitro fertilization (IVF) procedure, repeated sonographic scanning of follicular diameters in stimulated cycles was performed, until the largest visible follicle reached a mean diameter of at least 28 mm, at which time human chorionic gonadotropin (hCG) was administered. Follicle puncture was performed either guided by sonography or by laparoscopy 34–36 hr after the hCG injection, and following insemination oocytes were cultured for 48–60 hr before embryo transfer (ET). Serum levels of luteinizing hormone (LH), prolactin (PRL), and estradiol-17β (E₂) at the time of hCG injection as well as follicular fluid levels of follicle stimulating hormone (FSH), LH, and PRL as well as progesterone (P), testosterone (T), and E₂ at the time of puncture were determined in retrospect using specific radioimmunoassay (RIA). It was found that the knowledge of a single value of LH or E₂ in serum should have been of little additional value for the decision to give hCG in all stimulation models used: clomiphene+hCG, human menopausal gonadotropin (hMG)+hCG, and clomiphene+hMG+hCG. The concentrations of the three steroids measured in follicular fluid were, in a high proportion of the follicles, within a normal range in all stimulation models. The group receiving clomiphene+hMG+hCG appeared promising through its higher proportion of estrogenic follicles. It is concluded that sonographic measurement of follicular diameters may be used as the sole index of follicular maturity in an IVF program. In cases with more pronounced superovulation as may be obtained by hMG stimulation, serial E₂ analyses are required in addition in order to ensure a high proportion of estrogenic follicles and an optimal pregnancy rate.