Bleeding of fetal origin:

Ref: Text hook of Obstetrics by D.C.Dutta, 7th ed. P.g. 260.Explanation:VASA PREVIA:Umbilical vessels in velamentous placenta lie below the presenting part and run across the cervical os. This is called vasa previa.The vessels are torn sequentially/ following rupture of membranes.This is the only condition where antepartum hemorrhage is of fetal origin.Sanger's alkali denaturation test (Apt's test) is the confirmatory test.DiagnosisThe classic triad of the vasa praevia is:Membrane rupturePainless vaginal bleedingFetal bradycardia.This is rarely confirmed before deliverySuspected when antenatal sonogram w ith color- flow Doppler reveals a vessel crossing the membranes over the internal cervical os.The diagnosis is usually confirmed after delivery on examination of the placenta and fetal membranes