随着辅助生殖技术的发展以及促排卵药物的不规范应用,近年来多胎妊娠尤其是双胎的发生率有所增加,最常见的就是双胎妊娠。双胎妊娠其因并发症多、处理困难的特殊性,给产前诊断带来挑战。胎儿超声检查是孕妇孕期必做的检查项目,具有无创、直观、经济等特点,是产前诊断手段之一。随着科技发展,超声仪器分辨率得到很大提高,使得很多胎儿结构异常能在早孕期 With the development of assisted reproductive technology and the non-standard application of ovulation induction drugs, the incidence of multiple pregnancies, especially twins, has increased in recent years. The most common one is twin pregnancies. Twin pregnancy because of its complications, the handling of the particularities of difficulty to prenatal diagnosis challenges. Fetal ultrasound examination is pregnant women must do during pregnancy inspection items, with non-invasive, intuitive, economical and other characteristics of prenatal diagnosis is one of the means. With the development of science and technology, the resolution of ultrasound instruments has been greatly improved, making a lot of fetal structural abnormalities in early pregnancy