联体双胎是一种罕见的畸形,系单卵双胎于妊娠早期未完全分离,或由于分裂过晚,因而两个胚胎共一卵黄囊所致。此种畸形,往往内脏发育不全。容易早产、胎死宫内、或生产后短时间内死亡。存活者仅少数,纵形联胎一般分娩不困难。早产死胎或联结部位有较大活动性的横形联胎亦能自然分 Siamese twins is a rare deformity, the Department of monozygotic twins not fully separated in early pregnancy, or due to the division too late, so a total of two embryos yolk sac caused. Such deformities, often visceral hypoplasia. Easy premature delivery, intrauterine fetal death, or death within a short period of time after production. Only a small number of survivors, longitudinal births general delivery is not difficult. Premature birth or joint part of the greater mobility of the transverse cross-linked fetal can also be natural points