Preimplantation genetic screening: who benefits?

Objective: To compare IVF outcomes between women undergoing frozen transfers of blastocysts verified as euploid by preimplantation genetic screening (PGS) with patients undergoing fresh nonbiopsied blastocyst transfers.

Design: Retrospective cohort study.

Setting: Academic medical center.

Patient(s): All patients undergoing IVF-PGS cycles between January 2010 and November 2014 were included (n = 274). Patients were compared with a control group consisting of all fresh blastocyst transfers that occurred during the same period (n = 863).

Intervention(s): Patients underwent IVF-PGS with 24-chromosome screening. Patients with euploid embryos had transfer of one to two embryos in a subsequent frozen ET cycle.

Main Outcome Measure(s): Implantation, clinical intrauterine gestation (CIG), miscarriage, biochemical pregnancy (BC), and live birth (LB) rates were compared.

Result(s): Odds ratios (ORs) were estimated for outcomes in women undergoing PGS versus controls. Among patients ≤37 years old, there were no differences in CIG and LB rates for single (adjusted ORs [aORs], 1.20 [95 %confidence interval {CI}, 0.66-2.21]; 1.21 [95% CI, 0.66-2.2]) and double ETs (aORs, 1.09 [95% CI, 0.54-2.18]; 0.87 [95% CI, 0.44-1.7]). BC and miscarriage rates were also similar. For patients >37 years old, CIG and LB rates were increased for single (aORs, 3.86 [95% CI, 1.25-11.9]; 8.2 [95% CI, 2.28-29.5]) and double ETs (aORs, 9.91 [95% CI, 2.0-49.6]; 8.67 [95% CI, 2.08-36.2]) with no difference in BC and miscarriage rates. A per-retrieval analysis of the >37 group failed to demonstrate any difference in CIG or LB rates.

Conclusion(s): Among patients ≤37, IVF-PGS does not improve CIG, LB, and miscarriage rates. IVF-PGS in women >37 improved CIG and LB rates. However, per cycle, the PGS advantage in this age group does not persist.