Is there any link between a two vessel cord and a placental abruption?

No.: Two vessel cord (i.e. Single umbilical artery) is seen in ~1% of all babies and is generally a normal variant. There is no association with placental abruption which is a notoriously impossible diagnosis to predict on an individual basis. Single umbilical artery may be associated with increased risk for small and anomalious babies and requires frequent testing after 32 weeks (fetal surveillance).