AUTHOR=Zhang Chunhui , Wu Fangrong , Wu Zexuan , Sun Bolan , Chen Cheng , Qian Weiping 

TITLE=Early Follicular Phase Human Chorionic Gonadotropin Addition May Improve the Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection in Patients With “Unpredictable” Poor Response to Gonadotropin-Releasing Hormone Antagonist Protocol

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2021.739773

DOI=10.3389/fendo.2021.739773

ISSN=1664-2392

ABSTRACT=Purpose
To compare the effects of early and mid-late follicular phase administration of 150IU hCG on gonadotrophin-releasing hormone (GnRH) antagonist protocol in “unpredictable” poor ovarian response (POR) women undergoing in vitro fertilization / intracytoplasmic sperm injection (IVF/ICSI) treatment.
Methods
A retrospective single-center cohort study was conducted on 67 patients with “unpredictable” POR in their first IVF/ICSI cycle receiving GnRH antagonist protocol. Patients were treated with a second IVF/ICSI cycle using the same GnRH antagonist protocol with the same starting dose of rFSH as the first cycle, a daily dose of 150 IU hCG was administrated either on stimulation day 1 (Group A, n=35) or day 6 (Group B, n=32). The number of oocytes retrieved, number of usable embryos, serum level of estradiol (E2) on day of hCG trigger, and clinical pregnant outcomes were studied.
Results
The addition of 150IU hCG either on the first day or sixth day of stimulation increases the serum level of E2, LH and hCG on the day of hCG trigger. Only the use of 150IU hCG on the first stimulation day improved the number of oocytes retrieved, mature of oocytes, and usable embryos, but not the addition of hCG on stimulation day 6. Implantation rate, clinical pregnancy rate and ongoing pregnancy rate showed an increasing trend in patients receiving 150IU hCG in the early phase compared to mid-late phase, even thought there was no statistically significant difference. 
Conclusions
Our study demonstrated that adding 150IU hCG in subsequent GnRH antagonist cycle in “unpredictable” poor responders is associated with the improvement of response to stimulation. Furthermore, early follicular phase addition of 150IU hCG significantly increased the number of oocytes retrieved and usable embryos compared to the mid-late addition of same dose.