Methods 340 cases in post expected date of confinement pregnancies were retrospectively analysed.Women were divided into two groups (Oligohydramnios group, n=96, normal amniotic fluid group, n=244).

• 方法采用回顾性分析方法，对延期妊娠分娩的产妇羊水正常组244例及羊水过少组96例进行对比分析。