'When Lightning Strikes Twice'-Preimplantation Genetic Testing for Two Indications in One Biopsy.

Objective: We aimed to investigate whether the clinical pregnancy and live birth rates in women undergoing preimplantation genetic testing for two indications (PGT2) differ from PGT for one autosomal dominant indication (PGT1).

Method: This retrospective cohort study summarizes data from 44 PGT patients treated between 2015 and 2023. Data were divided into PGT2 (n = 22 patients, 113 treatment cycles) and PGT1 (n = 22 patients, 108 treatment cycles) groups. Statistical analysis included descriptive statistics, independent t-tests, Mann-Whitney U tests, mixed models, and multivariable mixed logistic regressions.

Results: The groups did not differ in clinical pregnancy and live birth rates. PGT2 patients had more fresh embryos per cycle than the PGT1 group (4.84 vs. 3.18 respectively; p = 0.067) and a significantly lower number of frozen embryos after biopsy (0.29 vs. 0.60 respectively; p = 0.037). No difference was found regarding the mean suitable embryos for biopsy. The PGT2 group had fewer embryos to transfer per cycle (1.30 vs.1.89; p = 0.007), yet there was no difference regarding the number of transferred embryos per cycle.

Conclusion: Testing for two genetic indications in one biopsy is feasible yet yields a lower proportion of embryos genetically suitable for transfer but with a similar live birth rate.