Efficacy of low-dose human chorionic gonadotropin alone to complete controlled ovarian stimulation

Objective: To prove that low-dose hCG alone can be clinically used to replace FSH-containing gonadotropins to complete controlled ovarian hyperstimulation (COH). Design: Controlled, prospective, randomized study. Setting; Academic center. Patient(s): Infertile patients who are candidates for assisted reproduction. Intervention(s): Patients received [1] recombinant FSH or hMG throughout COH (group A); [2] ovarian priming with recombinant FSH/hMG followed by low-dose hCG (200 IU/day) alone (group B). Main Outcome Measure(s): Medication consumption; daily serum and follicular fluid (FF) measurements of LH, FSH, hCG, E-2, P, T, and androstenedione (A); number and size of follicles; intracytoplasmic sperm injection (ICSI) outcome. Result(s): In group B: [1] duration and dose of recombinant FSH/hMG administration were reduced; [2] preovulatory serum hCG, E-2, and T were higher, whereas FSH was lower; [3] FF hCG, E-2, T levels, and E-2/T, E-2/A, and E-2/P ratios were higher, whereas A was lower; [4] small but not large preovulatory follicles were reduced; [5] fertilization rates were higher; and [6] serum and FF P levels, and ICSI outcome did not differ. Conclusion(s): low-dose hCG alone in the late COH stages: [1] reduced recombinant FSH/hMG consumption whereas ICSI outcome was comparable to traditional COH regimens; [2] stimulated follicle growth and maturation independent of FSH administration; [3] was associated with a reduced number of small preovulatory follicles; [4] did not cause premature luteinization; [5] resulted in a more estrogenic intrafollicular environment.