The information about pregnancy complication, umbilical cord, placenta, amnio fluid, delivery pattern and Apgar score was recorded.

• 于分娩前2天内应用超声测量脐动脉血流S/D值,并记录下有无妊娠合并症如妊高征(PIH)、早产、臀位等和脐带、胎盘、羊水性状及分娩方式、新生儿Apgar评分,比较不同分组间S/D值的差异。