探讨早孕期超声筛查多胎胎儿巨膀胱的图像特征及临床价值。

对2011年1月至2016年4月在南京医科大学鼓楼临床医学院产前诊断中心受检的2159例多胎妊娠孕妇产前检查资料进行回顾性分析，于妊娠11~13^＋6周行早孕期超声筛查，并于胎儿正中矢状面测量膀胱长径，彩色多普勒显示双脐动脉，对检出的多胎巨膀胱胎儿，追踪妊娠过程及临床结局。

早孕期超声筛查检出多胎之一巨膀胱胎儿6例，膀胱长径均大于7 mm，彩色多普勒均显示双脐动脉，其中双胎妊娠5例（为双胎之一胎儿巨膀胱），三胎妊娠1例（为三胎之一胎儿巨膀胱）。2例自然妊娠双胎之一巨膀胱胎儿均经引产终止妊娠，术后大体病理显示巨膀胱胎儿为梅干腹综合征。4例体外受精-胚胎移植多胎胎儿中，2例经早孕期选择性减胎术减去巨膀胱胎儿，其中1个正常胎儿足月活产，另一胎儿于孕32周超声显示双肾回声增强，行基因芯片检查，发现17 q12存在约1.5 Mb缺失；1例双胎妊娠孕妇未选择产前干预，其中巨膀胱胎儿死产，另一胎儿存活；1例双绒毛膜双羊膜囊三胎中单绒毛膜单羊膜囊双胎于孕13^＋2周自然胎死宫内，另一正常胎儿足月分娩。

早孕期超声筛查可有效地检出及诊断多胎胎儿巨膀胱，重视多胎妊娠胎儿巨膀胱的早期产前诊断并及时干预，有助于产科处理并改善妊娠结局。

To determine the imaging features and clinical value of first-trimester ultrasonographic screening of fetal megacystis in multifetal pregnancy.

Retrospective analysis was undertaken in 2159 cases of multifetal pregnancy screened in our hospital at gestational age from 11th to 13^{+ 6}th weeks by color Doppler ultrasound between Jan 2011 and April 2016. Fetal bladder was defined by showing two umbilical arteries and the longitudinal length of the bladder was measured in mid-sagittal plane. Clinical progression of fetal megacystis diagnosed in first-trimester were followed and the outcomes were recorded.

Totally six cases of fetal megacystis in multifetal pregnancy were detected, in which five cases were detected in one fetus of twin pregnancy and the other case was detected in one fetus of triplet pregnancy. In all cases of fetal megacystis, longitudinal length of the fetal bladder was more than 7 mm and double umbilical arteries were detected. In two cases of naturally-occurring twin pregnancy, abortion was performed and postnatal autopsy revealed prune belly syndrome. In the rest four cases of multifetal pregnancy through in vitro fertilization-embryo transfer (IVF-ET), two cases of twin pregnancies underwent selective feticide. The other two cases of twin and triplet pregnancies refused intervention, among which still birth happened in the megacystis fetus and spontaneous fetal death at gestational age of 13^{+ 2} weeks happened in the monochorionic monoamniotic twins of the triplet pregnancy. Totally, four live babies were born, among which three were healthy. The other baby was found to have 1.5 Mb deletion in chromosome 17q12 by microarray at gestational age of 32 weeks due to increased renal echogenicity.

First-trimester ultrasonography can effectively detect and diagnose megacystis in multifetal pregnancy. Early diagnosis and timely intervention are helpful for improving the outcome of fetal megacystis in multifetal pregnancy.