Compared with conventional insemination, intracytoplasmic sperm injection provides no benefit in cases of nonmale factor infertility as evidenced by comparable euploidy rate

Abstract

Objective: To evaluate whether differences in euploidy rates exist between intracytoplasmic sperm injection (ICSI) and conventional insemination (CI) in nonmale factor infertility cases.

Design: Retrospective cohort study.

Setting: A single, academically affiliated infertility center in the United States.

Patients: A total of 3554 patients who underwent in vitro fertilization cycles from January 2014 to December 2021. All cycles that had preimplantation testing for aneuploidy (PGT-A) performed by trophectoderm biopsy and had a postpreparation sperm concentration >4 million total motile sperm per milliliter were included.

Main outcome measures: The primary outcome was the embryo euploidy rate per embryo biopsied in the ICSI vs. CI group. Secondary outcomes included the fertilization rate and number of embryos biopsied. Generalized estimating equations with a Poisson distribution were used to estimate the euploid rate ratio (with total embryos biopsied as an offset), while accounting for multiple retrievals per patient. To adjust for confounding, a propensity score model was fit for ICSI using 14 baseline female and male characteristics.

Results: Oocytes retrieved and the number of embryos biopsied were similar in both groups, while the fertilization rate per oocyte retrieved was significantly lower with ICSI (0.64 vs. 0.66). The proportion of euploid embryos in the ICSI group was significantly lower when compared with CI (0.47 vs. 0.52), with a euploid rate ratio of 0.89. Interestingly, when accounting for the variation in PGT reference laboratories over the study time period, adjusting for the date of procedure did not change the relationship between ICSI and euploid rate (rate ratio = 0.89); however, after adjusting for the PGT reference laboratory, the relationship between ICSI and euploid rate was no longer significant (rate ratio = 0.97).

Conclusions: In the setting of nonmale factor infertility, ICSI resulted in a lower fertilization rate and an 11% lower embryo euploid rate compared with CI. Although the data are not statistically significant when adjusted for the PGT reference laboratory, we still can conclude that ICSI does not provide any benefit. These data support the recommendation that CI should be the preferred methodology for fertilization in nonmale factor infertility cases.

Keywords: Conventional insemination; ICSI; PGT-A; euploidy rate; nonmale factor infertility.