Chan D P
Med J Aust. 1976 Apr 3;1(14):480, 482-3.
Twins may be dizygotic or monozygotic. Of the monozygotic twins, 25% to 30% are dichorionic and 70% to 75% are monochorionic. Whilst all the dichorionic twins are diamniotic, very occasionally some monochlorionic ones may be monoamniotic; some of these may be conjoined. A case of conjoined twins was diagnosed during pregnancy. The two girls were delivered by elective classical caesarean section. They were joined together from just above the xiphisternum to the umbilicus and were successfully separated. Recent literature is reviewed.
双胞胎可能是双卵双胎或单卵双胎。在单卵双胎中，25%至30%为双绒毛膜，70%至75%为单绒毛膜。虽然所有双绒毛膜双胞胎都是双羊膜囊的，但极少数单绒毛膜双胞胎可能是单羊膜囊的；其中一些可能是联体的。一例联体双胞胎在孕期被诊断出来。这两个女孩通过选择性古典剖宫产分娩。她们从剑突下上方到脐部相连，并成功分离。本文对近期文献进行了综述。
