Most common cause of post paum hemorrhage: September 2009

Ans. B: Uterine Atony The 4Ts of postpaum hemorrhage (PPH): tone, trauma, tissue, thrombosis, and traction. More than one of these can cause postpaum hemorrhage in any given patient. Uterine atony - "Tone": Atony is by far the most common cause of postpaum hemorrhage. Uterine contraction is essential for appropriate hemostasis, and disruption of this process can lead to significant bleeding. Uterine atony is the typical cause of postpaum hemorrhage that occurs in the first 4 hours after delivery. Risk factors for atony include the following: Overdistended uterus (e.g., multiple gestation, fetal macrosomia, polyhydramnios) Fatigued uterus (e.g., augmented or prolonged labor, amnionitis, use of uterine tocolytics such as magnesium or calcium channel blockers) Obstructed uterus (e.g., retained placenta or fetal pas, placenta accreta, or an overly distended bladder) Trauma to the genital tract accounts for 20% of cases