Effective blastocyst cryopreservation markedly increases cumulative pregnancy rates per ova retrieval in donor ova and non-donor cycles independent of patient age

Abstract

OBJECTIVE: To compare the pregnancy rates of 990 fresh IVF/ICSI with 212 FET blastocyst transfers as a function of patient age. DESIGN: Ongoing longitudinal review. MATERIALS AND METHODS: From Jan. 2007 to Dec. 2008, an extended culture with triple gas system was used for 990 fresh IVF/ICSI cycles. After transfer the left blastocysts were cryopreserved by slow rate method. At the same time, 212 blastocyst FET cycles were completed. Main outcome measures: clinical pregnancy rate (CPR) (defined as viable delivery and/or ongoing pregnancy). RESULTS: The pregnancy rates of different patient age groups are shown in table 1 for donor and non-donor cycles. Table 1: Pregnancy results by age group in 990 fresh IVF/ICSI cycles and 212 blastocyst FET cycles.Table 1Pregnancy results by age group in 990 fresh IVF/ICSI cycles and 212 blastocyst FET cycles.Donor<35 yrs35-37 yrs38-40yrs≥41 yrsTotalFresh Cycle #187273164162204990Fresh Cycle Pregnancy rate142 (76%)178 (65.2%)89 (54.3%)76 (46.9%)58 (28.4%)543 (54.8%)Fresh Cycle CPR129 (69%)148 (54.2%)66 (40.2%)58 (35.8%)40 (19.6%)441 (44.5%)FET Cycle #5289271810212Blastocysts thawed147267734737571Survived # (rate)137 (93.2%)242(90.6%)67(91.8%)38(80.9%)36(97.3%)520(91.1%)Average ET#2.52.62.523.62.4FET Pregnancy rate34 (65.4%)64 (71.9%)18 (66.7%)10 (55.6%)3 (30%)129 (60.8%)FET CPR31 (59.6%)55 (61.8%)14 (51.9%)9 (50%)2 (20%)111 (52.4%) Open table in a new tab CONCLUSIONS: Fresh CPR was similar to FET CPR in the Donor group (69% vs. 59.6%, P =0.6536). No significant differences in CPR were found in all age groups between fresh and cryopreserved embryo transfer cycles. Effective blastocyst cryopreservation is a highly effective method to increase the cumulative clinical pregnancy rate per ova retrieval.