Abstract
To explore the association between uterine volume and in vitro fertilization (IVF) reproductive outcomes of infertile patients with adenomyosis, we performed a retrospective cohort study of infertile patients with adenomyosis who underwent IVF from January 2009 to December 2019 in our clinical center. Patients were divided into five groups according to the uterine volume before the IVF cycle. A line graph was drawn to demonstrate the linear trend of IVF reproductive outcomes with uterine volume. Univariate and multivariate analyses were used to explore the association between uterine volume of adenomyosis patients and IVF reproductive outcomes in first fresh embryo transfer (ET) cycle, first frozen-thawed embryo transfer (FET) cycle, and per ET cycle. Kaplan-Meier curves and Cox regression were conducted to evaluate the association between uterine volume and cumulative live birth. A total of 1155 infertile patients with adenomyosis were included. Clinical pregnancy rate showed no significant correlation with uterine volume in first fresh ET cycle, first FET cycle, and per ET cycle; miscarriage rate showed an upward trend with uterine volume increasement, in which the uterine volume turning point was 8 weeks of gestation; live birth rate showed a downward trend with turning point of 10 weeks of gestation. Subsequently, patients were divided into two groups (uterine volume ≤ 8 weeks of gestation vs. uterine volume > 8 weeks of gestation). Univariate and multivariate analyses showed that patients with a uterus larger than 8 weeks of gestation had a higher miscarriage rate and a lower live birth rate in all ET cycles. Kaplan-Meier curves and Cox regression demonstrated lower cumulative live birth rate in patients with a uterine volume larger than 8 weeks of gestation. IVF reproductive outcome gets worse as uterine volume increases in infertile patients with adenomyosis. Adenomyosis patients with a uterus larger than 8 weeks of gestation had a higher miscarriage rate and a lower live birth rate.