I have nursed a few people with it. 1 by memory were picked up when a VE was attended during labour and the midwife could feel the pulsation of the vessels through the membranes. It was then diagnosed during her c/s. I know there have been others also and of them some have delivered vaginally and others c/s. I have not ever seen a bad outcome from this or an early delivery or even an elective c/s but that is most likely because they usually are unknown until after delivery