超声在预测双胎妊娠新生儿出生体质量差异中的价值

Value of ultrasonography in predicting the birth weight discordance of twin pregnancy

目的·研究胎儿估计体质量(EFW)差异与新生儿出生体质量(BW)差异间的关系,评估超声预测双胎妊娠的新生儿出生体质量差异(?BW)的准确性。方法·应用超声检测不同孕周双胎的生长参数,对各项参数进行统计学分析,探讨EFW差异(?EFW)与?BW之间的关系。结果·在277对双胎中,44对双胎(15.9%)存在2个胎儿?BW≥20%。该现象在双绒毛膜双羊膜囊双胎(DCDA)与单绒毛膜双羊膜囊双胎(MCDA)的发生率分别为68.2%和31.8%,两者差异无统计学意义(P>0.01)。与孕期其他孕周评估的?EFW相比,分娩前末次超声评估的?EFW与?BW一致性最佳。在MCDA中,孕22~24周超声评估?EFW的阴性预测值最高(94%)。结论·双胎妊娠胎儿出生前末次超声评估的?EFW与?BW的一致性最高。对超声未发现?EFW较大即?EFW<20%的双胎,尤其是孕22~24周阶段MCDA中?EFW<20%者,其未来发生选择性宫内生长受限(s IUGR)机会较小。

Objective. To identify the relationship between the estimated fetal weight （EFW） discordance and birth weight （BW） discordance, and evaluate the accuracy of ultrasonography in predicting birth weight discordance （ABW） of twin pregnancy. Methods. The ultrasound was used to detect the growth of twins at different gestational weeks and the data were analyzed to compare the difference between EFW discordance （AEFW） and ABW. Results. About 15.9 percent of twins （totally 277 cases） had severe ABW （ABW ≥ 20%） in our study, and the percentages of dichorionic-diamniotic twin （DCDA） and monochorionic-diamniotic twin （MCDA） were 68.2% and 31.8%, respectively （P〉0.01）. Compared with AEFW in other gestational weeks, AEFW last time before parturition was most consistent of ABW. Furthermore, the negative predictive value of MCDA was highest （94%） at 22-24 gestational weeks. Conclusion. Twin ABW was relatively better predicted by AEFW last time before parturition. Twin pregnancy without severe AEFW （AEFW〈20%）, especially MCDA with AEFW〈20% at 22-24 weeks, had low probability of selective intrauterine growth restriction in the future.