# Impact of COVID-19 infection on laboratory and clinical outcomes of ovarian stimulation using antagonist protocol

## TL;DR

This study examines how COVID-19 infection affects outcomes of ovarian stimulation in assisted reproduction, finding no major negative effects on laboratory or clinical results.

## Contribution

The study provides new insights into the impact of prior COVID-19 infection on repeat ovarian stimulation outcomes using a self-controlled design.

## Key findings

- No significant differences in ovarian reserve or response between pre- and post-infection cycles.
- Infected patients did not show improved embryo rates in repeat cycles, unlike non-infected patients.
- Blastocyst formation rates increased in infected patients with a specific post-infection interval.

## Abstract

The COVID-19 profoundly impacted human reproduction, and provoked concerns regarding its potential influence on the assisted reproduction treatment outcomes. The current study designed to explore the impact of COVID-19 infection on the laboratory and clinical outcomes of patients who underwent controlled ovarian stimulation (COS) with antagonist protocol.

This strictly self-controlled study included 134 patients who underwent repeated oocyte retrieval at the reproductive medicine center of International Peace Maternity and Child Health Hospital of China Welfare Institute between January 1, 2022 and December 31, 2023. Sixty six patients were contracted COVID-19 between their first and second COS cycles, and 68 patients were uninfected controls. We evaluated the laboratory outcomes, including oocyte yield and the rate of MII oocyte, fertilization, usable embryo, and high-quality embryo, through both inter-group (infected vs. non-infected) and intra-individual (before vs. after infection) comparisons.

The baseline characteristics were comparable between infection and non-infection groups. Ovarian reserve and response profiles demonstrated no statistically significant differences between the first and second COS cycles within either group. In the non-infection group, both the available and high-quality embryo rate showed significant improvement in the second COS cycle. In the infection group, although the blastocyst formation rate was significantly higher after COVID-19 infection (p = 0.011), the high-quality embryo rate did not differ significantly between the pre- and post-infection cycles. We also stratified the infection group into five subgroups based on the interval from infection to oocyte pick-up. An increase in both total and high-quality blastocyst rates was observed in the subgroup with an interval of 181–240 days post-infection. The pregnancy outcomes were similar between infection and non-infection group.

Our data revealed that increased available and high-quality embryo rates seen in the non-infection group during second COS cycle were not observed in infected patients. Nonetheless, when comparing intra-individual, no detrimental effects on laboratory or clinical outcomes were found. This indicates that while COVID-19 appears to compromise the advantages of a repeat cycle, it does not worsen ovarian function.