孕20周:16-20.5CM;
孕21周:17-21.5CM;
孕22周:18-22.5CM;
孕23周:19-23.5CM;
孕24周:20-24.5CM;
孕25周:21-25.5CM;
孕26周:21.5-26.5CM;
孕27周:22.5-27.5CM;
孕28周:23-28.5CM;
孕29周:23.5-29.5CM;
孕30周:24-30.5CM;
孕31周:25-31.5CM;
孕32周:26-32.5CM;
孕33周:27-33.5CM;
孕34周:27.5-34.5CM;
孕35周:28.5-35.5CM;
孕36周:29-36.5CM;
孕37周:29.5-37.5CM;
孕38周:30.5-38.5CM;
孕39周:31-38.5CM;
孕40周:32-38.5CM.