卵黄囊大小及形态变化与早孕流产关系

目的探讨妊娠早期阶段经超声观察卵黄囊(YC)的形态以及内径与早期自然流产的关系。方法经腹部超声检查517名单胎自然受孕的孕妇并进行随访,孕妇根据妊娠情况分为正常妊娠组、先兆流产组和自然流产组,观察并记录卵黄囊的大小、形态,妊娠囊的内径。结果超声最早在孕5周时检出卵黄囊,在孕9周内径最大,此后内径缩小,孕12周左右消失,与妊娠囊内径呈平方关系,回归方程:Y=2.290+0.09X-0.001X2,决定系数R2=0.634,P=0.000;自然流产组中,10例卵黄囊未显示,32例小于正常,11例正常大小,9例大于正常,7例变形,7例钙化,3例回声异常;卵黄囊的形态及大小异常在先兆流产组及自然流产组间差异有统计学意义(P<0.05);logistic回归分析显示,未检出卵黄囊、卵黄囊大小和卵黄囊形态异常是流产的独立危险因素。结论卵黄囊的形态以及大小与妊娠结局存在密切联系,早孕阶段通过超声检测卵黄囊可以作为预测妊娠结局的方法之一。

Relationship between changes of diameter and shape of yolk sac and early abortion

Objective To explore the relationship between diameter and shape of yolk sac(YC)and early spontaneous abortion.Methods Totally 517 cases of singleton pregnant women were detected by abdominal ultrasound and were followed up.All cases were divided into the normal pregnancy group,threatened abortion group and spontaneous abortion group according to the pregnancy outcomes.The size and shape of yolk sac,the inner diameter of gestational sac were recorded.Results Ultrasound could detected the yolk sac at 5 weeks of pregnancy.The inner diameter of gestational sac was the largest at 9 week and then the diameter was narrowed and disappeared at 12 week.The changes of inner diameter of the gestational sac showed a square relation to gestational time with a regression equation of Y=2.290+0.09X-0.001X2 and a coefficient of R2=0.634(P=0.000).There were 10 cases with no yolk sac detected,32 cases with the size less than normal,11 cases with normal size,9 cases with the size larger than normal,7 cases with deformation,7 cases with calcification,and 3 cases with abnormal echo.The anomalies of shape and size of yolk sac for threatened abortion and spontaneous abortion group were different and the difference was statistically significant(P<0.05).logistic regression analysis showed that the detection of the yolk sac,the size and shape of yolk sac were independent risk factors for abortion.Conclusion The size and shape of yolk sac were closely related to the pregnancy outcomes.The yolk sac detection by ultrasound at the early stage of pregnancy was a predictor of pregnancy outcome.