Effect of culture conditions and method of conception on mouse live birth rate

Zhuoni Xiao; Annemarie Donjacour; Royce Harner; Rhodel Simbulan; Chia-Ning Kao; Elena Ruggeri; Xiaowei Liu; Emin Maltepe; Paolo Rinaudo

doi:10.1016/j.xfss.2020.10.002

Effect of culture conditions and method of conception on mouse live birth rate

F S Sci. 2020 Nov;1(2):132-141. doi: 10.1016/j.xfss.2020.10.002. Epub 2020 Oct 13.

Authors

Zhuoni Xiao¹, Annemarie Donjacour², Royce Harner², Rhodel Simbulan², Chia-Ning Kao², Elena Ruggeri³, Xiaowei Liu², Emin Maltepe⁴, Paolo Rinaudo⁵

Affiliations

¹ Center for Reproductive Medicine, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China; Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California.
² Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California.
³ Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California; San Diego Zoo Global, Escondido, California.
⁴ Department of Pediatrics, University of California, San Francisco, California.
⁵ Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California. Electronic address: paolo.rinaudo@ucsf.edu.

PMID: 35559924
DOI: 10.1016/j.xfss.2020.10.002

Abstract

Objective: To understand in a mouse model whether there are differences in the decidua and live birth rate after transfer of blastocysts generated by in vitro fertilization (IVF) or by superovulation with spontaneous mating into unstimulated recipients.

Design: Animal experiment.

Setting: University-affiliated tertiary hospital.

Animal(s): Mice.

Intervention(s): IVF embryos were generated and cultured in either Whitten medium (WM, suboptimal conditions) and 20% O₂ or KSOM medium with amino acids (KAA, optimal conditions) and 5% O₂. The control blastocysts from superovulated mice were flushed out of the uterus 3.5 days (E3.5) after mating (FB group). The resulting blastocysts were transferred to nonsuperovulated CF1 recipients mated to vasectomized males. To understand whether anomalies of decidua were present, the expression of genes involved in decidual development and inflammation was analyzed at E7.5 and E18.5. Similarly, immunostaining was used to evaluate whether the pathways involved in activation of mTORC1 (p-S6) and Cox2 signaling (Cox 2 staining) were altered.

Main outcome measure(s): Live birth rate, gene expression, and immunostaining of decidua.

Result(s): Implantation rates at E7.5 were similar, but in vivo embryos (FB groups) were predicted to result in live births 3.3 times higher (2.2-5.1) and 6.6 times higher (4.7-9.3) compared with optimal and suboptimal cultures, respectively. Expression of genes involved in decidual development and inflammation or localization and intensity of staining for p-S6 (mTOR pathway), or inflammation (Cox 2 pathway) were not different among the groups.

Conclusion(s): The predicted live birth rate was decreased in mouse embryos generated by IVF compared with embryos generated by mating, whereas the implantation rate was not different. Suboptimal culture conditions resulted in lower birth rate. We did not find evidence of abnormalities in decidualization that could explain these findings. These data indicate that blastocysts cultured in stressful conditions are less competent, suggesting that decreasing the number of embryonic manipulations may result in higher live birth rates.

Keywords: Assisted reproductive technology; decidua; implantation; live birth.