A randomized controlled dose-response pilot study of addition of hCG to recombinant FSH during controlled ovarian stimulation for in vitro fertilization

Abstract

Study question: Is it possible to define an optimal dose of hCG in combination with rFSH from the first day of stimulation in the GnRH agonist protocol applied to IVF?

Summary answer: Supplementation with hCG from the first day of stimulation may increase the number of top-quality embryos per patient. Daily doses of hCG up to 150 IU are compatible with good live birth rates. A ceiling level of estradiol (E(2)) was reached with hCG doses above 100 IU/day. A positive dose-response was seen for pre-ovulatory progesterone, but concentrations remained below values for which an impairment of endometrial receptivity has been previously reported. We suggest a large clinical trial to be proceeded with a group given 100 IU hCG daily versus a control group.

What is known and what this paper adds: Prospective multicentre studies have indicated increased live birth rates and increased number of top-quality embryos when low doses of hCG were associated with FSH. We analysed the clinical, embryological and endocrine aspects of adding increasing doses of hCG to rFSH from the first day of stimulation for IVF.

Design: A prospective randomized, controlled, open-label dose-response pilot study was conducted between February 2009 and June 2010 at Copenhagen University Hospital, Rigshospitalet, Denmark. Adequate allocation concealment was assured from sequentially numbered, opaque, sealed envelopes prepared from a computer-generated list. Scoring of the embryos was done in an assessor-blinded way.

Participants and setting: Endocrinologically normal IVF patients aged 25-37 years, BMI 18-30 kg/m(2), regular cycles and FSH <12 IU/l, were treated with a fixed dose of rFSH 150 IU/day and randomized to daily hCG dose of 0, 50, 100 or 150 IU from Day 1 of stimulation. Primary end-point was the total number of top-quality embryos on Day 3.

Data analysis method: Data were analysed by analysis of variance, Kruskal-Wallis test, chi-squared test or Poisson distribution count.

Main findings: A total of 62 patients were randomized into four hCG dose groups: Dose 0 (D0; n= 16), Dose 50 (D50; n= 15), Dose 100 (D100; n= 16) and Dose 150 (D150; n= 15). Two patients in D150 were withdrawn after randomization because of major (10- to 30-fold) hCG dosing errors, leaving 13 patients in this group. Thus, the results are based on the per protocol population. The mean numbers of top-quality embryos per patient were D0: 0.8 ± 1.2, D50: 0.5 ± 0.7, D100: 1.2 ± 1.7 and D150: 1.5 ± 1.7 (P= 0.04). All pregnancies were singleton gestations, and the live birth rates per started cycle were D0: 25%, D50: 27%, D100: 25% and D150: 31% (P= 0.98). Steady state level of serum (s)-hCG was reached on Day 6 of stimulation. S-hCG levels (IU/l) on the day of hCG administration were D0: <0.1, D50: 3.1 (2.6-3.6), D100: 5.5 (4.1-7.4) and D150: 11.0 (8.9-13.6) (P< 0.01). The patients receiving hCG supplementation were stratified by 33 and 66% percentiles into three groups according to the concentration of s-hCG on Day 6 of stimulation: 0.5-3.5 IU/l (n= 16), 3.5-8.0 IU/l (n= 14) and 8.0-21.1 IU/l (n= 14). The mean numbers of top-quality embryos in the three groups were 0.5 ± 0.9, 1.1 ± 1.8 and 1.5 ± 1.5, respectively (P= 0.03). The progesterone increments from stimulation Day 1 to the day of hCG triggering were D0 = 49%, D50 = 79%, D100 = 110% and D150 = 160% (P= 0.02). S-androstenedione level was highest in D150 (P< 0.01). S-E(2) was 2-fold higher in the D100 and D 150 compared with D0 (P= 0.09). BIAS, LIMITATION, GENERALISABILITY: Our study has a limited sample size. Supplementation with daily hCG dose up to 150 IU throughout stimulation has never been used before. Hence, this had to be tested in a small study before conducting a larger trial.

Study funding/competing interests: Ferring Pharmaceuticals, Research and Development, provided funds for the endocrine measurements. CLINICALTRIAL.GOV REGISTRATION: NCT00844311.