Dosage of exogenous gonadotropins is not associated with blastocyst aneuploidy or live-birth rates in PGS cycles in Chinese women.

STUDY QUESTION: Is the total dose of exogenous gonadotropins associated with blastocyst aneuploidy or live-birth rates in PGS cycles in Chinese women?

SUMMARY ANSWER: The total dose of exogenous gonadotropins is not significantly associated with blastocyst aneuploidy or live-birth rates in PGS cycles in Chinese women.

WHAT IS KNOWN ALREADY: The administration of gonadotropins in ovarian stimulation leads to supraphysiological steroid concentrations compared with those seen during natural cycles. The rate of euploid blastocytes is negatively associated with female age.

STUDY DESIGN, SIZE, DURATION: This is a retrospective study using anonymised data on PGS cycles performed in China from 2013 to 2017. Data from 1088 PGS cycles and 3219 embryos were analysed by array-comparative genomic hybridization (array-CGH).

PARTICIPANTS/MATERIALS, SETTING, METHODS: The study included 944 women who underwent PGS cycles with COH. All cycles were analysed by the total dose of exogenous gonadotropins (<1500, 1500-3000 and >3000 IU), patient age (<35 and ≥35 y.o.) and number of oocytes retrieved (1-5, 6-10, 11-15 and >15 oocytes).

MAIN RESULTS AND THE ROLE OF CHANCE: In the group of younger women (<35 y.o., 537 PGS cycles), the incidence of aneuploidy ranged from 36.9 to 43.4% when data was stratified by gonadotropins dose. After adjusting for confounding factors, the dose of exogenous gonadotropins was not associated with the blastocyst aneuploidy rate. Similar results were shown in the group of women with advanced maternal age (≥35 y.o., 551 PGS cycles), with no difference in the rate of blastocyst aneuploidy among different gonadotropins dose groups (<1500 IU, 58.0%; 1500-3000 IU, 59.8%; and >3000 IU, 59.8%; P = 0.86). The live-birth rates after single cryopreserved blastocyst transfers were also not significantly associated with the gonadotropins dose.

LIMITATIONS, REASONS FOR CAUTION: Limitations include the retrospective study design and the heterogeneity of the included patients. Additionally, array-CGH may not be able to correctly identify mosaicism.

WIDER IMPLICATIONS OF THE FINDINGS: The finding that gonadotropin dosage is not associated with embryonic aneuploidy or live-birth rates in Chinese women suggests that the high doses of gonadotropins used in ART cycles may be safe. The findings are consistent with those of prior studies in other populations.

STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Natural Science Foundation of China (81671522) and National Key Research and Development Program of China (2016YFC1000202).

TRIAL REGISTRATION NUMBER: N/A.