Background: Ovarian hyperstimulation syndrome (OHSS) remains one of the most serious complications in IVF cycles. hCG the gold standard for ovulation trigger carries the risk of initiating the cascade of events leading to OHSS, especially in patients with high ovarian response. In patients undergoing IVF using the GnRH antagonist protocol with GnRH agonist trigger instead of hCG there is a lower risk of OHSS but on the expense of a lower pregnancy rate than patients receiving the traditional hCG trigger.
Aim of work: To evaluate whether a single dose of hCG 1500 units given to patients using the GnRH agonist trigger would improve pregnancy rates, without increasing the risk of OHSS.
Patient and Methods: This is a randomized controlled trial, set in Adam International IVF Hospital from December 2014 till June 2015. 154 patients undergoing IVF using the GnRH antagonist protocol and triggered with GnRH agonist. Administering a single dose of hCG 1500 units immediately after ovum pick-up, compared to no hCG. Main outcome measure is chemical pregnancy rate. Other outcome measures include clinical pregnancy rate and incidence of OHSS.
Results: There was a significant difference in chemical and clinical pregnancy rates (58.8% vs 35.9%, P 0.0485, 51.6% vs 20.0%, P 0.0001) in favour of intervention. No cases of severe OHSS were recorded in either groups.
Conclusion: Giving a single dose of hCG 1500 units immediately after ovum pick-up significantly improves pregnancy rates without increasing the incidence of severe OHSS. The trial was registered with Pan African Clinical Study Registry (www.pactr.org), no. PACTR201512000952372.