Influence of maternal obesity on embryonic vitrification injury and subsequent pregnancy outcomes: A retrospective cohort study

Zhonghong Zeng; Jingjing Li; Xi Wang; Shanjia Yi; Yin Bi; Dan Mo; Bo Liu; Xiaoqian Fu; Yihua Yang; Wenhong Ma

doi:10.1016/j.heliyon.2023.e20095

Influence of maternal obesity on embryonic vitrification injury and subsequent pregnancy outcomes: A retrospective cohort study

Heliyon. 2023 Sep 12;9(9):e20095. doi: 10.1016/j.heliyon.2023.e20095. eCollection 2023 Sep.

Authors

Zhonghong Zeng^{1

2

3}, Jingjing Li⁴, Xi Wang^{1

2

3}, Shanjia Yi^{1

2

3}, Yin Bi^{1

2

3}, Dan Mo^{1

2

3}, Bo Liu¹, Xiaoqian Fu¹, Yihua Yang^{1

2

3}, Wenhong Ma^{1

5}

Affiliations

¹ Guangxi Reproductive Medical Center, the First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, China.
² Guangxi Key Laboratory of Immunology and Metabolism for Liver Diseases, Nanning, 530021, China.
³ Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Nanning, 530021, China.
⁴ Reproductive Medicine Center, Liuzhou Municipal Maternity and Child Health Care Hospital, Liuzhou, 545001 China.
⁵ Reproductive Medicine Center, Nanning Women and Children's Hospital, Nanning, 530011 China.

Abstract

Background: We previously reported that obese mice had significantly high lipid content in embryos, and excessive lipids are detrimental to embryonic development. However, whether maternal obesity has an effect on embryonic vitrification injury and subsequent pregnancy outcomes is still controversial. This study was conducted to clarify the influence of maternal obesity on embryonic vitrification injury and subsequent pregnancy outcomes by in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

Methods: We retrospectively collected medical record of IVF/ICSI patients from reproductive medicine centers in two tertiary hospitals. The patients were classified into a low-weight group (<18.5 kg/m2), normal-weight group (18.5-23.9 kg/m2), overweight group (24.0-27.9 kg/m2) and obese group (≥28.0 kg/m2) according to their body mass index (BMI). Multivariable logistic regression analysis was performed to compare pregnancy outcomes in fresh and frozen embryo transfer among different BMI groups to define the correlation between BMI and embryonic vitrification injury.

Results: A total of 44 773 women among 20-40 years old were recruited in this study, of which 27 797 underwent their first fresh embryo transfer and 16 976 underwent their first frozen embryo transfer. For fresh embryo transfer, there was no significant difference in the clinical pregnancy rate, live birth rate, and miscarriage rate of 4 BMI groups. For frozen-thawed embryo transfer, there was a significant increase in the clinical pregnancy rate of the overweight group (AOR = 1.14, 95% CI: 1.05-1.25) and the obese group (AOR = 1.24, 95% CI: 1.03-1.50), while the miscarriage rate (AOR = 1.42, 95% CI: 1.05-1.92) also showed a significant increase in the obese group compared to the normal-weight group.

Conclusion: This study provided a new understanding of the effect of maternal obesity on embryonic vitrification injury. Maternal obesity does not worsen the outcome of IVF/ICSI, particularly in the frozen-thawed group.

Keywords: Embryonic vitrification injury; ICSI; IVF; Obesity; Pregnancy outcome.