Ovarian stimulation with daily late follicular phase administration of low-dose human chorionic gonadotropin for in vitro fertilization: a prospective, randomized trial

Evaluate the effectiveness of a new ovarian stimulation (OS) protocol before IVF. Prospective clinical randomized trial. Private centers. Three hundred and twenty-three intended-to-treat women candidates for IVF. Patients were divided into three groups and administered the following treatments: group A, recombinant hFSH from day 3 until follicles reached 13–14mm, when recombinant hFSH was lowered to 75 IU daily and daily injections of 200 IU of hCG and a GnRH antagonist were administered until final maturation; group B, recombinant hFSH and a GnRH antagonist; group C, recombinant hFSH and a GnRH agonist. Primary outcome was the number of mature oocytes. Secondary outcomes included average initial and total recombinant hFSH dosage, serum E 2 level on day of ovulation, number of oocytes retrieved, fertilization, number of top-quality embryos, endometrial thickness, implantation rate, pregnancy rate (PR), and incidence of ovarian hyperstimulation syndrome (OHSS). The numbers of oocytes retrieved, mature oocytes, fertilization, top-quality embryos, and embryos transferred were comparable in all groups. Implantation rate, PR, and incidence of OHSS were also comparable. The total dose of recombinant hFSH was significantly lower in group A (1,674.7 ± 59.4 IU, vs. 2,197.9 ± 77.8 IU in group B and 2,156.7 ± 80.9 IU in group C). This new OS protocol permits follicles and oocytes to fully develop, helps generate top-quality embryos, avoids premature ovulation, establishes clinical pregnancies, reduces administration of recombinant hFSH, minimizes costs, and does not increase the chances of OHSS.