Serum human chorionic gonadotropin levels are correlated with body mass index rather than route of administration in women undergoing in vitro fertilization-embryo transfer using human menopausal gonadotropin and intracytoplasmic sperm injection

Objective: To compare subcutaneous (SC) and intramuscular (IM) hCG administ ration and their association with body mass index (BMI) in women undergoing IVF-ET using hMG and ICSI. Design: Prospective, randomized controlled trial. Setting: Private infertility clinic. Patient(s): Twenty-one ovulatory women, 29-39 years, were enrolled. Treatme nt of one patient who failed to respond to hMG was canceled. Intervention(s): A standard IVF-ET treatment plan using an initial dose of 300 U of hMG was followed. Patients were randomly assigned to receive 10,00 0 IU hCG, either IM in the gluteal region or SC in the lower abdomen. Exact ly 12 hours later, serum for hCG determination was obtained. All oocytes we re fertilized using ICSI technology. Main Outcome Measure(s): Human chorionic gonadotropin levels 12 hours after injection, BMI, and oocyte maturity. Result(s): No significant differences in hCG levels were found, with mean l evels of 225 +/- 24 mIU/mL for SC injection versus 213 +/- 26 mIU/mL for IM injection. No differences were observed in the percentage of mature oocyte s. A significant negative correlation was found between BMI and hCG levels in all patients, regardless of route of administration. Conclusion(s): The highest levels of hCG were measured in women with the lo west BMI. Patients' body size, rather than route of hCG delivery, appears t o determine circulating levels of hCG. (C) 2001 by American Society for Rep roductive Medicine.