Rupture of the marginal sinus of the placenta proved to be one of the most common causes of antepartum bleeding in two hospitals. This lesion has an important association with prematurity. Bleeding from the marginal sinus usually is not serious for the mother. The importance of the lesion lies in the necessity of differentiating it from more serious conditions such as abruption and placenta previa.
Ferguson JH. RUPTURE OF THE MARGINAL SINUS OF THE PLACENTA. JAMA. 1958;166(5):476-478. doi:10.1001/jama.1958.02990050046009