Placenta Praevia
Placenta previa (placenta previa AE) is an obstetric complication in which the placenta is attached to the uterine wall close to or covering the cervix. It can sometimes occur in the later part of the first trimester, but usually during the second or third. It is a leading cause of antepartum haemorrhage (vaginal bleeding). It affects approximately 0.5% of all labours.
Placenta praevia is hypothesized to be related to abnormal vascularisation of the endometrium caused by scarring or atrophy from previous trauma, surgery, or infection.
In the last trimester of pregnancy the isthmus of the uterus unfolds and forms the lower segment. In a normal pregnancy the placenta does not overlie it, so there is no bleeding. If the placenta does overlie the lower segment, as is the case with placenta praevia, it may shear off and a small section may bleed.
Read more about Placenta Praevia: Diagnosis, Incidence, Risk Factors, Intervention
Famous quotes containing the word placenta:
“The past grows gradually around one, like a placenta for dying.”
—John Berger (b. 1926)