目的 研究经阴道彩超对异位妊娠卵黄囊的检出同母体血清游离人绒毛膜促性腺激素（β-HCG）水平异常的相关性。方法 选择我院2011年5月至2013年9月共109例异位妊娠孕妇作为研究对象，抽取尿样检测β-HCG标准浓度并抽血清测β-HCG，随访至分娩。根据异位妊娠包块内是否有卵黄囊显示分为两组，观察其血清β-HCG水平及卵黄囊包块最大直径的差异。结果 109例孕妇中显示卵黄囊者59例，未显示卵黄囊者50例，其中有卵黄囊者β-HCG水平明显高于对照组（P<0.01）。结论 异位妊娠包块内可见卵黄囊的病例相应孕血清游离β-HCG水平异常，所以测定β-HCG有利于较早预防不良妊娠结局。

Objective To study the correlation between the detection of yolk sac by transvaginal sonography and serum levels of human chorionic gonadotropin (beta-HCG) in ectopic pregnancy. Methods The serum beta-HCG levels in 109 cases of ectopic pregnancy and normal controls were detected. According to the presence of yolk sac bag piece display in ectopic pregnancy, the patients were divided into two groups, the serum beta HCG levels and yolk sac bag piece diameter in two groups were observed. Results There were 59 cases of patients showed the yolk sac among 109 patients. The serum beta-HCG levels in patients with yolk sac were significantly higher than that of control group. Conclusion The serum free beta-HCG levels in ectopic pregnancy patients with yolk sac are abnormal, and the determination of beta HCG is conducive to early prevention of adverse pregnancy outcomes.