Unicornuate uteri are associated with infertility, miscarriage, preterm delivery and even uterine rupture. The aim of this research was to investigate the effects of unicornuate uterine anomaly on twin pregnancies after in vitro fertilization-embryo transfer (IVF-ET). A total of 206 women with unicornuate uteri (A singleton, B selective reduction (SR) of twins to a singleton, C twins) and 314 women with normal uteri (D SR of twins to a singleton, E twins) who delivered at ≥22 weeks were included. C was associated with a significantly lower live birth rate (adjusted odds ratio (aOR) 0.08, 95% confidence interval (CI), 0.01–0.69) and higher risks of preterm delivery (aOR 11.63, 95% CI, 4.85–27.92), perinatal mortality (aOR 11.43, 95% CI, 1.44–90.57) and low birth weight (aOR 5.92, 95% CI 1.94–18.06) than A, a 15-fold greater risk of preterm delivery (aOR 15.54, 95% CI 3.09–78.28) than B and a greater risk of preterm delivery (aOR 2.76, 95% CI 1.33–5.73) than E. After SR to a singleton, the perinatal outcomes were statistically similar between B and D. These results showed that the risk of twin pregnancies should be minimized in patients with unicornuate uterine anomaly undergoing IVF-ET.

单角子宫与不孕、流产、早产甚至子宫破裂有关。本研究的目的是探讨单角子宫异常对体外受精-胚胎移植（IVF-ET）后双胎妊娠的影响。共有 206 名单角子宫女性（A 单胎，B 双胞胎选择性减胎术 (SR) 为单胎，C 双胞胎）和 314 名正常子宫女性（D SR 双胞胎为单胎，E 双胞胎）分娩时间≥22周数也包括在内。 C 与显着较低的活产率（调整后优势比 (aOR) 0.08，95% 置信区间 (CI)，0.01–0.69）和较高的早产风险相关（aOR 11.63，95% CI，4.85–27.92），围产期死亡率（aOR 11.43，95% CI，1.44–90.57）和低出生体重（aOR 5.92，95% CI 1.94–18.06）比A高15倍，早产风险高15倍（aOR 15.54，95% CI 3.09– 78.28）比 B 更高，早产风险（aOR 2.76，95% CI 1.33-5.73）比 E 更高。SR 为单胎后，B 和 D 的围产期结果在统计学上相似。这些结果表明双胞胎的风险对于接受 IVF-ET 的单角子宫异常患者，应尽量减少妊娠。