Single embryo transfer with comprehensive chromosome screening results in improved ongoing pregnancy rates and decreased miscarriage rates

Abstract

BACKGROUNDSingle embryo transfer (SET) provides the most certain means to reduce the risk of multiple gestation. Regrettably, prospective trials of SET have demonstrated reductions in per-cycle delivery rates. A validated method of comprehensive chromosome screening (CCS) has the potential to optimize SET by transferring only euploid embryos. This retrospective study evaluates the efficacy of SET with CCS in an infertile population.METHODSOverall and age-controlled ongoing pregnancy rates (OPR) were compared between women undergoing SET following CCS (CCS-SET, n= 140) and those undergoing SET without aneuploidy screening (control SET, n= 182). All transfers were at the blastocyst stage, with CCS performed after trophectoderm biopsy of expanded blastocysts and analysis with rapid PCR allowing for fresh transfer.RESULTSIn the CCS-SET and control SET groups, an OPR of 55.0 and 41.8%, respectively, was obtained. The OPR was lower for the control group (P< 0.01) despite a younger age than the CCS group (37.3 ± 3.4 versus 34.2 ± 3.9 years; P< 0.001). Birthweight and gestational age at delivery were equivalent. The proportion of clinical pregnancies resulting in miscarriage was higher in the control group (24.8 versus 10.5%, P< 0.01), with more patients requiring surgical interventions for aneuploid pregnancies. There was one monozygotic twin delivery in the CCS group and none in the control group.CONCLUSIONSCompared with traditional blastocyst SET, SET after trophectoderm biopsy and rapid PCR-based CCS increases OPR and reduces the miscarriage rate. The enhanced selection empowered by CCS with SET may provide a practical way to eliminate multi-zygotic multiple gestation without compromising clinical outcomes per cycle.

Live birth following double-factor pre-implantation genetic diagnosis for both reciprocal translocation and alpha-thalassaemia

“…2 Since 2008, there was emerging evidence regarding the use of array CGH in both translocation carriers and preimplantation aneuploidy screening. [3][4][5] Using aCGH, it could obtain information on all 24 chromosomes to detect aneuploidy, which is common in early human embryos, other than in translocated genetic material. 4 Recourse to WGA in aCGH allowed us to use a single blastomere for both diagnoses as the amplified products could also be used for PCR.…”

The optimal timing of blastocyst vitrification after trophectoderm biopsy of preimplantation genetic screening

“…Expanding and expanded blastocysts underwent TE biopsy on day 5 or 6. The blastocyst quality was assessed immediately before TE biopsy, defined according to the criteria presented by Gardner and Schoolcraft (1999) [19]; only the blastocysts considered to be of a desirable quality (4,5,6, AB, BA, and BB) were subjected to biopsy. After TE biopsy, blastocysts were cultured in microdrops of a blastocyst medium with 15% SPS and a three-gas incubator until vitrification.…”

“…The high efficiency of PGS at the blastocyst stage has being reported as a key factor determining the growing clinical application of this strategy worldwide [2][3][4][5][6][7]. For blastocyst biopsy, laser-assisted drilling is used to create a zona opening on day 3 or day 5 of development.…”

A greater number of euploid blastocysts in a given cohort predicts excellent outcomes in single embryo transfer cycles

“…Improved pregnancy rates and decreased miscarriage rates have been reported in SET cycles following CCS compared with SET using standard morphologic criteria [31,28]. Recent data from a randomized controlled trial even demonstrated that a SET of a chromosomally normal embryo has similar pregnancy rates to a DET of untested embryos [32].…”