构建正常胎儿中晚孕期肠管宽度产前超声正常值范围，为诊断胎儿肠管异常扩张以及临床评估胎儿肠管发育状况提供参考依据。

选取2020年9月至2021年3月在北京协和医院进行常规中晚孕期产前超声检查的孕妇，测量胎儿肠管宽度，随访妊娠结局及胎儿出生情况。应用LMS统计方法拟合胎儿肠管宽度随孕周变化的P3、P5、P10、P25、P50、P75、P90、P95及P97的百分位曲线。

研究共纳入正常中晚孕期单胎妊娠孕妇224例，胎儿肠管宽度各百分位曲线随孕周增加呈逐渐上升趋势，从25~40周，胎儿肠管最大宽度第95百分位值从8.00 mm增加到21.76 mm，胎儿肠管最大宽度第97百分位值从8.22 mm增加到22.97 mm。

研究得出中晚孕期正常胎儿肠管宽度的参考值范围和生长曲线，其中P95、P97值为诊断胎儿肠管异常扩张提供依据，对临床评估胎儿肠管发育状况具有重要意义。

To establish the normal range of fetal bowel width during middle and late pregnancy to provide a reference for the diagnosis of abnormal intestinal dilatation and intestinal malformations.

Singleton pregnant women who underwent routine middle and late prenatal ultrasound were selected at Peking Union Medical College Hospital from September 2020 to March 2021. Fetal bowel width was measured, and pregnancy outcome was followed up. Based on gestational age, the percentile curves of fetal bowel width (P3, P5, P10, P25, P50, P75, P90, P95, and P97) were fitted by the LMS statistical method.

A total of 224 women with singleton pregnancy were enrolled in this study. The curves of the 95th percentile of the maximum width of the fetal bowel ranged from 8.00 mm to 21.76 mm, and the 97th percentile of the maximum width of the fetal intestine was 8.22 mm to 22.97 mm at 25 to 40 weeks.

The reference value and growth curve of normal singleton fetal bowel width during middle and late pregnancy have been obtained. The P95 and P97 values providea a basis for the diagnosis of abnormal intestinal dilatation, which is of great significance for clinical applications.