Controlled ovarian hyperstimulation parameters are not associated with chromosomal abnormality rates and clinical pregnancy outcomes in preimplantation genetic testing.

OBJECTIVE

This study aimed to determine whether controlled ovarian hyperstimulation (COH) parameters influence the incidence of chromosomal abnormalities (> 4 Mb) in blastocysts and, thus, clinical pregnancy outcomes in preimplantation genetic testing (PGT).

METHODS

Couples who underwent preimplantation genetic testing for structural chromosome rearrangements (PGT-SR) and monogenic disorders (PGT-M) were included in this study. The relationships of maternal age, paternal age, stimulation protocol, exogenous gonadotropin dosage, duration of stimulation, number of oocytes retrieved and estradiol (E) levels on human chorionic gonadotropin (hCG) trigger day with the incidence of chromosomal abnormalities were assessed. Blastocysts were biopsied, and nuclear DNA was sequenced using next-generation sequencing (NGS). Clinical pregnancy outcomes after single euploid blastocyst transfers under different COH parameters were assessed.

RESULTS

A total of 1,710 and 190 blastocysts were biopsied for PGT-SR and PGT-M, respectively. The rate of chromosomal abnormalities was found to increase with maternal age ( 0.001) and paternal age ( = 0.019) in the PGT-SR group. No significant differences in the incidence of chromosomal abnormalities were seen for different maternal or paternal age groups between the PGT-SR and PGT-M groups ( > 0.05). Stratification analysis by gonadotropin dosage, stimulation protocol, duration of stimulation, number of retrieved oocytes and E levels on hCG trigger day revealed that chromosomal abnormalities and clinical pregnancy outcomes were not correlated with COH parameters after adjusting for various confounding factors.

CONCLUSION

The rate of chromosomal abnormalities was found to increase with maternal or paternal age. COH parameters were found to not influence the incidence of chromosomal abnormalities or clinical pregnancy outcomes.