Use of the natural cycle and vitrification thawed blastocyst transfer results in better in-vitro fertilization outcomes : cycle regimens of vitrification thawed blastocyst transfer.

摘要

PURPOSE: To compare the IVF outcomes of vitrification-thawed blastocyst transfer cycles utilizing different endometrial preparation methods. METHODS: We retrospectively assessed IVF outcomes in 611 patients (648 cycles) who underwent blastocyst frozen embryo transfer (FET) between January 2007 and December 2009. All embryos had been cryopreserved by a vitrification method following a previous IVF cycle. Patients were prepared for transfer by using either the natural cycle (n = 310/Group 1), the natural cycle with ovulation induction employing human chorionic gonadotropin (n = 134/Group 2), or a hormonally manipulated artificial cycle with estrogen and progesterone supplementation (n = 204/Group 3). RESULTS: Multivariate logistic regression analysis showed a significant difference in clinical pregnancy rate between Groups 3 (30.4%) and 1 (41.9%) (odds ratio [OR], 0.567; 95% confidence interval [CI], 0.379-0.847, P = 0.006) whereas the difference between Groups 2 and 1 was not significant (41.8% vs. 41.9%; OR, 0.683; 95% CI, 0.435-1.073; P = 0.098). Other significant variables affecting clinical pregnancy rate were the number of embryos transferred, the grade of transferred embryos, and maximal endometrial thickness. CONCLUSION: The results showed that, using vitrification-thawed blastocyst transfer, employment of natural cycles with or without hCG treatment was associated with better outcomes than was the use of hormonally manipulated cycles.