GNRH1 and ovarian hyperstimulation syndrome: Antagonists are increasingly widely used in clinical practice due to their short ovulation induction time and low Gn dosage. A meta-analysis compared the clinical outcomes of long GnRH-a regimens and GnRH-ant regimens in patients with a normal ovarian reserve and found that compared with GnRH-a regimens, GnRH-ant regimens significantly reduced the incidence of OHSS without affecting the pregnancy rate or live birth rate.