True knot and torsion of cord are cause by occasional factors and difficult to prevent.

脐带异常中脐带真结节、扭转均属偶然因素，难以预防。

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Objective: to determine obstetrical risk factors and pregnancy outcome of fetuses with true knot of the umbilical cord.

目的：探讨脐带真结的危险因素及其妊娠结局。

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Researchers also discovered the husband and wife who will stay true to their 'til death us do part' vow will have met through friends - and tied the knot after three and a half years together.

研究人员还发现，经朋友认识、并在交往三年半后结婚的夫妇会长相厮守。

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