Human chorionic gonadotropin (HCG) type does not effect the rate of embryo development

Abstract

OBJECTIVE: The aim of this study was to assess two hCG preparations: r-hCG (Ovidrel®250mcg or 6250IU) and u-hCG (Pregnyl®10,000IU) and the rate of embryo development in clinical practice. DESIGN: Retrospective observational. MATERIALS AND METHODS: 286 ICSI treatment cycles between September 2007 and Dec 2007 were analysed. A GnRH agonist mid-luteal down regulation with 150-450 IU of recombinant FSH (r-FSH) depending on patient aetiology was employed. When at least two follicles had reached 18mm diameter final follicular maturation was induced with 250 mcg r-hCG or 10,000 IU u-hCG. Oocyte retrieval was scheduled 38 hours later. ICSI was performed on Metaphase II oocytes. Syngamy assessed 24 hours post insemination (hpi), day 2 assessment occurred between 42- 44 hpi, day 3 at 64-68 hpi. Blastocyst transfer occurred 5 days post-OPU. A clinical pregnancy was defined as a fetal heart 6 weeks after embryo transfer and implantation rate defined as the number of viable fetal hearts per embryo transferred. ANOVA was used for continous data and Chi Square for categorical data; statistical significance was set at P<0.05. RESULTS: Table 1.Table 1r-hCG (250mcg or 6250 IU)u-hCG (10 000 IU)P value (∗P<0.05)Age (years)34.0 +/− 3.735.3 +/− 3.60.007∗BMI (kg/m^2)24.9 +/− 5.824.7 +/− 5.60.78Daily gonadotropins IU262.3 +/− 112.6267.3 +/− 111.20.72Number MII oocytes8.4 +/− 5.09.1 +/− 6.10.25Number 2PN zygotes5.6 +/− 3.96.8 +/− 4.90.01∗Day 2 (cell number)4.1 +/− 0.034.0 +/− 0.050.46Day 3 (cell number)8.6 +/− 0.048.7 +/− 0.050.13Clinical Pregnancy37 %37%Implantation rate33%28% Open table in a new tab CONCLUSIONS: We conclude that r-hCG is as effective as u-hCG for inducing final follicular maturation in COS. Even though fertilisation rate is lower in r-hCG group, embryo development occurs as expected and is associated with similar pregnancy rates.