Prognostic factors associated with clinical pregnancy in in vitro fertilization using pituitary down-regulation with depot and daily low-dose luteal phase gonadotropin releasing hormone agonists: A single center's experience

AIM: To review the experience on depot-dose, and daily low-dose gonadotropin releasing hormone agonist (GnRHa) long protocols and identify prognostic factors. SETTING AND DESIGN: A chart review was conducted on 2106 depot and 1299 daily low-dose cycles at a university hospital. METHODS: Clinical parameters were summarized, and prognostic factors of clinical pregnancy for each protocol were identified by logistic regressions. Missing data were imputed using multiple imputations (MI) and the regression models were rerun after MI. RESULTS: Clinical pregnancy rate was 57.5% and 46.9% in the depot and daily low-dose groups, respectively. Logistic regressions with MI identified age (odds ratio [OR]: 0.95, 95% confidence interval [CI]: 0.92–0.98), serum progesterone (OR: 0.62, 95% CI: 0.45–0.84) and endometrial thickness (OR: 1.06, 95% CI: 1.02–1.12) on human chorionic gonadotropin (hCG) day, number of oocytes retrieved (OR: 1.04, 95% CI: 1.01–1.06), fertilization rate (OR: 2.66, 95% CI: 1.46–4.87) and ratio of good-quality D3 embryos (OR: 4.31, 95% CI: 2.79–6.67) as prognostic factors in the depot group. Age (OR: 0.95, 95% CI: 0.92–0.98), endometrial thickness on hCG day (OR: 1.09, 95% CI: 1.03–1.15), ratio of good quality D3 embryos (OR: 2.56, 95% CI: 1.59–4.13) and the number of cryopreserved embryos (OR: 1.07, 95% CI: 1.003–1.15) are prognostic for the daily low-dose protocol. Some regression coefficients that are significant under model-wise deletion become nonsignificant after MI. CONCLUSIONS: Age, embryo quality and endometrial thickness on hCG day are important prognostic factors for both 1.0/1.3 mg depot and 0.05/0.1 mg daily low-dose luteal phase GnRHa long protocols. MI is a valuable tool to gauge and address bias caused by missing data in reproductive medicine.