Effects of triploidy after intracytoplasmic sperm injection on in vitro fertilization cycle outcome

Objective

To evaluate the impact on the rates of clinical pregnancy and live birth of polyploidy after intracytoplasmic sperm injection (ICSI).

Design

Retrospective cohort study.

Setting

University-based IVF center.

Patient(s)

One hundred forty-three patients undergoing their first IVF–embryo transfer cycle requiring ICSI.

Intervention(s)

None.

Main Outcome Measure(s)

Patients were divided into two groups on the basis of the proportion of post-ICSI triploid fertilization that was observed at the time of fertilization assessment: group 1 included patients with ≤20% three-pronuclear (3PN) zygotes, and group 2 included patients with >20% 3PN zygotes. The primary outcomes compared between groups were pregnancy and implantation rates; secondary outcome measures included clinical-pregnancy rate and live-birth rate per embryo transfer.

Result(s)

Pregnancy, implantation, clinical-pregnancy, and live-birth rates were significantly higher in the cohort of patients who had ≤20% of embryos appearing triploid, compared with the group who had >20% of zygotes appearing triploid (relative risk [RR] for pregnancy, 2.4 [95% confidence interval {CI}, 1.22–4.77]; RR for implantation, 2.6 [95% CI, 1.17–5.56]; RR for clinical pregnancy, 2.8 [95% CI, 1.16–6.85]; and RR for live birth, 2.6 [95% CI, 1.06–6.38]). The proportion of 3PN zygotes after ICSI had a statistically significant inverse relationship to clinical-pregnancy rate.

Conclusion(s)

The proportion of triploid zygotes after ICSI serves as a negative prognostic indicator for IVF cycle outcome. This finding suggests that triploidy proportion is a surrogate marker of oocyte competence that represents the integrity of the oocytes in the entire recruited cohort. Such findings therefore may influence recommendations for embryo transfer number and freezing of supernumerary embryos.

Key Words: Polyploidy, triploidy, fertilization, ICSI, IVF outcome, oocyte competence, oocyte quality, live birth