Safety of laser double zona drilling for trophectoderm biopsy in preimplantation genetic testing

This study evaluates whether laser double-zona drilling (DZD) during trophectoderm biopsy improves clinical outcomes in preimplantation genetic testing (PGT).

A total of 545 couples who underwent PGT-A using trophectoderm biopsy between December 2016 and May 2023 were included in the study. PGT cycles were categorized into two groups: DZD and single-zona drilling (SZD). Seventeen baseline female and male characteristics were included as covariates. Propensity score matching (PSM) was used to reduce potential confounders. Generalized estimating equations with a Poisson distribution were used to estimate the ratios of clinical outcomes. The primary outcomes were live birth and twin birth rates. Secondary outcomes included clinical pregnancy and miscarriage rates.

Overall, twin birth rates in the DZD and SZD groups were 0.57% and 0.84%, respectively. Prior to PSM, the live birth rate, twin birth rate, and clinical pregnancy rate were similar in both groups, whereas the clinical pregnancy rate was significantly higher in the DZD group (adjusted RR = 1.15, 1.01-1.32, P = 0.039). After PSM was applied, there was no statistically significant difference in the live birth, twin birth, clinical pregnancy, or miscarriage rates between the two groups, as indicated by the adjusted rate ratios of 1.21 (0.80-1.83, P = 0.366), 0.95 (0.06-15.07, P = 0.969), 1.19 (0.87-1.64, P = 0.273), and 0.96 (0.55-1.67, P = 0.884), respectively.

Our study suggests the safety of using laser DZD for artificial blastocyst collapse during trophectoderm biopsy and provides novel evidence by comparing clinical outcomes with those of single zona drilling.