<prompt> Nitabuchs membrane is absent in:Placenta accreteVasa previaAbruption placentaPlacenta previa  <response>: Ans. a Placenta accretaRef: Williams obstetrics 23rded, Ch 35. The nitabuch layer is a zone of fibrinoid degeneration in which invading trophoblasts meet the decidua. If the decidua is defective, as in placenta accreta, the Nitabuch layer is usually absent.Also Know Placenta accreta indicates that villi are attached to the myometrium. Placenta increta, villi actually invade the myometrium. Placenta percreta defines villi that penetrate through the myometrium and to or through the serosa. 