A.0.5% B.1% C.1.5% D.2% E.2.5%
A.20% B.40% C.65.6% D.81.4% E.95%
A.上界相當(dāng)于第5腰椎上緣 B.外界在真骨盆最寬徑外1~2cm C.下界在宮頸的下緣 D.后界包括全部骶骨 E.前界在恥骨聯(lián)合前緣