Pre-vascular

Pre-vascular is a late pregnancy painless vaginal bleeding, often misdiagnosed as placenta previa or placental abruption ,delay in treatment cause fetal death.

Under normal circumstances, the umbilical cord attached to the placenta center or eccentric position, but there is a small amount of umbilical cord attached to the membranes around the placenta, the umbilical cord blood tube can be dispersed into several teams in between the amnion and chorion, and then attached to the edge part of the placenta . This scattered blood vessels, including two umbilical artery that is sometimes only a single umbilical artery (single umbilical artery) and one or 2,3 support the convergence from the umbilical vein, these vessels become a fan-shaped dispersion result of this attachment that for the umbilical cord attached to the fan-shaped (velamentous insertion of cord), blood vessels around the plastic无华Qualcomm (Whartons jelly) 1773 years Wrisberg first reported this discovery, if the umbilical cord attached to the fan-shaped lower uterine segment occurred in fetal presentation in the former, scattered vascular Wang across the cervix within the mouth, known as the pre-vascular (vasa previa).

Vascular risk of pre-presentation is the Department of decline, the direct oppression of blood vessels, leading to fetal distress, but it is more dangerous is the natural rupture of fetal membranes or artificial rupture of collagen fibers by the fixed-up in the fetal membranes can also be pre-vascular was bleeding injury happened. This bleeding is purely belong to fetal hemorrhage, on the mother-friendly, but extremely dangerous to the fetus.

In 1801 reported Lostein fan-shaped umbilical cord attached to lead to fetal death, and the first official pre-1831 vessels are Benckiser reported so far this fatal hemorrhage is still often called Benckiser's name.

Epidemiology:

Since 1831, the literature reported to the front of about 250 cases of blood vessels, of course, pre-vascular cases in fact far greater than this figure from 1970 to 1980 PaulinoQuck, Tan and other scholars, reported a larger number of series of pre-delivery of vascular the incidence of ~ 1:8333 to 1:1275, with an average incidence of about 1:4500 at Catanzarite et al (2001) report at 8 years, 33,208 cases of pregnant women with color Doppler examination revealed 12 cases of pre-vascular, in childbirth 10 cases of check by the obstetricians and placenta pre-identified as blood vessels, were 10 cases of fetal survival, and its incidence of about 1:3300.