Mosaic blastocysts diagnosed with next generation sequencing (NGS) have unique transcriptomic profiles different from those of euploid or aneuploid embryos

Abstract

(PGT). The primary outcome was the live birth rate (LBR). The secondary outcomes were the rates of implantation, ongoing pregnancy, miscarriage, multiple pregnancy, OHSS, ectopic pregnancy, preterm birth, pregnancy-induced hypertension, preeclampsia, birth weight, and congenital anomalies. Subgroup analysis included normal-and hyper-responder patients, embryo development stage on transfer day (cleavage vs. blastocyst), and freezing method (slow-freezing vs. vitrification). We also conducted sensitivity analyses to verify the leverage of individual studies on the pooled results. RESULTS: Eleven studies involving 5,379 patients fulfilled the inclusion criteria for this meta-analysis, and were subjected to qualitative and quantitative analysis. There was an increase in LBR when comparing freeze-all to fresh embryo transfer in the overall IVF/ICSI population (Relative Risk [RR] 1.07; 95% CI 1.01-1.14; I2¼46%; P¼0.02). Subgroup analyses indicated higher LBR with freeze-all than fresh ET in hyper-responders (RR 1.15; 95% CI 1.04-1.27; I2¼0%; P¼0.005) and PGT cycles (RR 1.55; 95% CI 1.14-2.10; P¼0.005). However, there was no differences in LBR in normal responders (RR 1.00; 95% CI 0.93-1.08; I2¼34%; P¼0.94). Sensitivity analyses demonstrated that the benefit of the freeze-all strategy in LBR became no significant by the removal of the PGT study (RR 1.06; 95% CI 1.00-1.12; I2¼22%; P¼0.07). The overall risk of preeclampsia was higher in the freeze-all group (RR 1.78; 95% CI 1.11-2.84; I2¼13%; P¼0.02), mainly due to an increased risk observed in hyper-responders (RR 3.12; 95% CI 1.26-7.73; P¼0.01). There were no statistical differences in all the other outcomes in the overall population. CONCLUSIONS: Although many practitioners have advocated the use of freeze-all strategy, to either the overall IVF population or a specific subset of patients, the benefit of this strategy is only observed in some particular groups of patients, such as hyper-responders and those submitted to PGT. Moreover, the freeze-all policy and subsequent FET may be associated with an increase in the risk of preeclampsia.