Mild starting dosage ovarian stimulation combined with a modified prolonged GnRH-a protocol improved IVF/ICSI outcomes in normal ovarian responders

INTRODUCTION: Controlled ovarian hyperstimulation (COH) is essential for artificial reproduction technology (ART). This study aimed to evaluate the effects of a mild starting dosage of r-FSH ovarian stimulation after the modified prolonged GnRH-a down-regulation protocol for COH on the clinical outcomes in normal ovarian responders undergoing in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET). MATERIAL AND METHODS: In the retrospective study, the patients were separated into two groups according to the starting dosage of r-FSH: a mild dosage group (75 IU ≤ r-FSH < 150 IU, n = 858) and a conventional dosage group (150 IU ≤ r-FSH ≤ 225 IU, n = 535). Data were collected from clinical records. The baseline characteristics and clinical outcomes were compared between the two groups. RESULTS: Although the duration of r-FSH treatment was a little longer in the mild dosage group, the total r-FSH dosage and the cost of ovarian stimulation were significantly lower than those in the conventional dosage group. Furthermore, compared to the conventional dosage group, the number of retrieved oocytes was also lower in the mild dosage group, whereas the rates of two pronuclei (2PN) fertilized oocytes and good-quality embryos were remarkable higher. The implantation rate, clinical pregnancy rate and live birth rate were significantly higher in the mild dosage group. There was no difference in early miscarriages rate, incidence of moderate and severe ovarian hyper-stimulation syndrome (OHSS) or incidence of ectopic pregnancy between the two groups. CONCLUSIONS: The modified prolonged GnRH-a pituitary down-regulation regimen combined with mild r-FSH starting dosage improved IVF/ICSI outcomes and reduced the financial cost in normal ovarian responders.