Clinical Study GnRH Agonist versus hCG Trigger in Ovulation Induction with Intrauterine Insemination: A Randomized Controlled Trial Minh Tam Le , 1 Dac Nguyen Nguyen, 1 Jessica Zolton, 2 Vu Quoc Huy Nguyen , 1 Quang Vinh Truong, 1 Ngoc Thanh Cao, 1 Alan Decherney, 2 and Micah J. Hill 2 1 Department of OBGYN, Hue University of Medicine and Pharmacy, Hue University, 06 Ngo Quyen Street, Hue, Vietnam 2 Department of OBGYN, Walter Reed National Military Medical Center, Bethesda, MD, USA Correspondence should be addressed to Minh Tam Le; leminhtam@huemed-univ.edu.vn Received 24 September 2018; Revised 27 November 2018; Accepted 24 December 2018; Published 13 March 2019 Academic Editor: Maria L. Dufau Copyright © 2019 Minh Tam Le et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This study is aimed at comparing clinical pregnancy rates (CPRs) in patients who are administered either gonadotropin-releasing hormone agonist (GnRHa) or human chorionic gonadotropin (hCG) for ovulation trigger in intrauterine insemination (IUI) cycles. A prospective randomized comparative study was conducted at Hue University Hospital in Vietnam. A total of 197 infertile women were randomly assigned to receive either GnRHa trigger (n = 98 cycles) or hCG trigger (n = 99 cycles) for ovulation trigger. Patients returned for ultrasound monitoring 24 hours after IUI to confirm ovulation. A clinical pregnancy was defined as the presence of gestational sac with fetal cardiac activity. There was no difference in ovulation rates in either group receiving GnRHa or hCG trigger for ovulation. Biochemical and CPR were higher in patients who received hCG (28.3% and 23.2%) versus GnRHa (14.3% and 13.3%) (p =0 023, OR 0.42, 95%CI = 0 21 - 0 86 and p =0 096, OR 0.51, 95%CI = 0 24 - 1 07, respectively). After adjusting for body mass index (BMI) and infertility duration, there was no difference in CPR between the two groups (OR 0.58, 95% CI 0.27-1.25, p =0 163). In conclusion, the use of the GnRHa to trigger ovulation in patients undergoing ovulation induction may be considered in patients treated with IUI. 1. Introduction Exogenous human chorionic gonadotropin (hCG) is com- monly used to achieve final oocyte maturation and trigger ovulation in patients undergoing ovulation induction. In assisted reproductive cycles, however, hCG trigger is asso- ciated with a higher risk of developing ovarian hyper- stimulation syndrome (OHSS) and premature luteinizing hormone (LH) surge [1]. It is widely accepted that the gonadotropin-releasing hormone agonist (GnRHa) can be used as an alternative with a comparative effect to hCG to achieve final oocyte maturation by inducing a LH and follicle-stimulating hormone (FSH) surge but decrease the risk of OHSS in in vitro fertilization (IVF) [2–5]. In patients undergoing ovulation induction with gonado- tropins and intrauterine insemination (IUI), because the number of developed follicles is limited, routinely not over 3, the risk of OHSS is negligible. A potential benefit to employing the use of GnRHa trigger for IUI cycles may be to induce a more physiologic type of gonadotropin surge involving the flare effect of FSH and LH from the pituitary [5]. In the natural menstrual cycle, there is a midcycle surge of both gonadotropins [6]. The FSH peak contributes to the resumption of meiosis and cumulus expansion and induces LH receptors in the granulosa cells [7–10]. hCG trigger is used as a surrogate to mimic the LH surge and does not result in a release of FSH [11]. A study of IVF patients who were given a bolus of FSH in addition to the hCG trigger found better oocyte recovery and fertilization rates in comparison to hCG trigger alone [12]. Conversely, GnRHa-triggered cycles result in a shorter duration of LH release in comparison to the natural men- strual cycle. The corpus luteum, which is stimulated by LH, may be defective. Studies have shown a shorter duration of the luteal phase after GnRHa trigger [13]. It has been reported that GnRHa are associated with lower pregnancy Hindawi International Journal of Endocrinology Volume 2019, Article ID 2487067, 6 pages https://doi.org/10.1155/2019/2487067