何谓多胎妊娠，多胎妊娠大体的发生率?
女，41岁，纺织工，腕部疼痛无力数周，结合CR和MR，最可能的诊断是() ["A．月骨结核","B．月骨缺血坏死","C．骨质疏松","D．骨髓炎","E．骨软骨炎"]
前置胎盘孕妇采用期待疗法的适应证是什么?
男，6岁，髋部疼痛、跛行半年，结合图像，最可能的诊断是() ["A．髋关节结核","B．股骨头骨骺缺血坏死","C．骨肉瘤","D．骨囊肿","E．软骨肉瘤"]
妊娠期高血压疾病(hypertensive disorder complicating pregnancy)
羊水过多的病因有哪些?
