Does the "freeze-all" policy allow for a better outcome in assisted reproductive techniques than the use of fresh embryo transfers? - A retrospective study on cumulative live birth rates.

OBJECTIVE: There are increasing concerns regarding the adverse effects associated with control ovarian hyperstimulation (COH) in both endometrial and uterine environments. With the "segmentation treatment policy" of assisted reproductive techniques (ART), endometrial problems may be obviated through embryo cryopreservation. However, it remains unclear if the "freeze-all policy" offers a better outcome when compared with fresh embryo transfer (ET). To clarify this, we compared the cumulative live birth rates (CLBRs) between these two patient populations.

MATERIALS AND METHODS: This is a retrospective study on 853 patients undergoing ovarian stimulation and ART (including IVF/ICSI) during the period from January 2012 to June 2014 in Taichung Veterans General Hospital, Taiwan, ROC. We followed up with these patients through to November 2016. Patients whose embryos were not completely transferred back were excluded. The study group ('freeze-all') included 84 patients whose cycles were performed initially without fresh ET, but were later given frozen-thawed ET. The control group ('fresh ET') had 625 patients whose cycles were performed with fresh ET, followed by frozen-thawed ET. Basic parameters and CLBRs were statistically compared between these two groups.

RESULTS: The CLBRs in the study group were significantly higher than those in the control group (64.3% vs. 45.8%, p = 0.001). Subgroup analysis revealed that when the number of oocyte pick up (OPU) is between 4 and 15, the CLBRs in the study group were significantly better (58.3% vs. 40.9%, p = 0.042). For those with OPU <4 or OPU >15 the CLBRs were similar in these two groups (OPU < 4: study vs. control 23.1% vs. 18.8% respectively, p = 0.713; OPU>15: study vs. control 85.7% vs. 80.8% respectively, p = 0.625) CONCLUSION: The Freeze-all policy improved the ART outcome for normal responders.