目的:寻找原因不明月经过少妇女的实验室和临床特征。方法:110名原因不明月经过少有生育意愿的妇女为研究组及330名月经正常有生育意愿的妇女为对照组,B超观察妇女子宫内膜容受性的临床特征,如内膜厚度、内膜类型、肌层回声、子宫动脉搏动指数以及内膜血流,同时测定黄体中期血雌二醇(E2)、孕酮(P)水平,血凝水平和抗体指标,并对妇女1年内的受孕情况进行随访。结果:研究组妇女的子宫内膜容受性评分低于对照组(9.41±3.02 vs 15.67±2.63,P<0.01),黄体中期E2水平较低(172.35±27.54 ng/L vs 220.27±30.28 ng/L,P<0.01)。研究组1年内自然受孕率低于对照组(60.0%vs 72.1%,P<0.05),孕早期自然流产率(33.3%vs 12.9%,P<0.01)较高。结论:原因不明月经过少妇女表现为子宫内膜容受性差,1年内自然受孕率低,建议在孕前给予黄体功能和子宫内膜容受性的检测。 Objective: To find out the laboratory and clinical features of women with unexplained menstruation. Methods: One hundred and fourteen women with unknown causes of childbearing after birth were selected as control group and 330 women with normal menstruation and fertility. B-ultrasound was used to observe the clinical features of endometrial receptivity of women, such as intima thickness, Endometrial type, muscular echo, uterine artery pulsatility index and endometrial blood flow. Meanwhile, the levels of E2, P, HPA and antibody in the mid luteal phase were measured. The situation of conception was followed up. Results: The endometrial receptivity score of study group was lower than that of control group (9.41 ± 3.02 vs 15.67 ± 2.63, P <0.01), E2 level was lower in intermediate stage of luteal phase (172.35 ± 27.54 ng / L vs 220.27 ± 30.28 ng / L, P <0.01). The spontaneous conception rate in the study group was lower than that in the control group (60.0% vs 72.1%, P <0.05) in one year and higher in the first trimester (33.3% vs 12.9%, P <0.01). Conclusions: The unexplained menorrhagia women showed poor endometrial receptivity and low rate of natural conception in one year. It is recommended to give corpus luteum function and endometrial receptivity before pregnancy.