Impacts of the COVID-19 pandemic on early pregnancy outcomes among women undergoing frozen-thawed embryo transfer: a retrospective cohort study

Abstract

The effect of COVID-19 pandemic on early pregnancy outcomes among women undergoing frozen-thawed embryo transfer (FET) remains unclear. We aimed to evaluate whether early pregnancy outcomes were altered in patients undergoing FET during the pandemic. In this retrospective cohort study, women conceived through FET in 2016–2021 from two hospitals in China were included. The early pregnancy outcomes were compared using Logistic regression model, including biochemical pregnancy rate (BPR), clinical pregnancy rate (CPR), and early pregnancy loss rate (EPLR). A total of 16,669 (67.2%) and 6,113 (26.8%) FET cycles enrolled before and during the pandemic, respectively. Univariate analyses showed that women undergoing FET during the pandemic had significantly increased BPR (72.9% vs. 69.7%) and CPR (59.5% vs. 55.0%), and significantly decreased EPLR (13.7% vs. 16.7%) compared to pre-pandemic (all P < 0.001). Moreover, after adjustment, the results were in accordance with univariate analysis for CPR [adjusted OR (95%CI) = 1.08 (1.01–1.14)] and EPLR [adjusted OR (95%CI) = 0.82 (0.73–0.91)], while the statistical significance between BPR and the pandemic disappeared. In summary, women conceived by FET did not have a reduced possibility of clinical pregnancy and a higher risk of early pregnancy loss during the pandemic compared with the pre-pandemic.

Keywords:

• COVID-19
• lockdown
• pregnancy outcomes
• frozen-thawed embryo transfer
• ART

Acknowledgements

We would like to thank the physicians, nurses, and scientific staff of Department of Reproductive Medicine of Maternity and Child Health Care Hospital in Nanjing and Changzhou, China.

Authors’ contributions

Juan Wen initiated, conceived, and supervised the study. Xin Li and Xiaodie Yao drafted the manuscript and conducted the statistical analysis. Lijing Bai, Renjie Lu, Shijie Geng, Lingmin Hu and Xiufeng Ling did data collection and quality control. All authors approved the final format of the submitted manuscript.

Availability of data and materials

The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.

Disclosure statement

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Statement of ethics

The institutional review board of Women’s Hospital of Nanjing Medical University approved the study (2020KY-011) and waived the requirement for informed consent because of the retrospective design.

Additional information

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by National Natural Science Foundation of China (81871210, 8197138).