Final answer:
The four predisposing factors to postpartum hemorrhage are uterine atony, retained placenta, maternal hypertension, and abruptio placentae. Uterine atony and a retained placenta directly contribute to the risk, whereas maternal hypertension and abruptio placentae are associated with complications that may lead to excessive postpartum bleeding.
Step-by-step explanation:
The four predisposing factors to postpartum hemorrhage are: a) Uterine atony, retained placenta, maternal hypertension, abruptio placentae. Uterine atony is a condition where the uterus fails to contract effectively after delivery, leading to excessive bleeding. A retained placenta occurs when the placenta, or parts of it, remain in the uterus instead of being expelled, increasing the risk of hemorrhage. Maternal hypertension and abruptio placentae (premature separation of the placenta) are additional recognized risk factors, although they do not themselves cause hemorrhage directly; rather, they are associated with complications that could lead to excessive bleeding.
Placenta previa and retained placenta are significant since they directly affect the delivery of the placenta, potentially leading to hemorrhage. Furthermore, conditions such as gestational diabetes, preterm labor, and cesarean section, found in option b), while they may complicate pregnancy and delivery, are not direct predisposing factors for postpartum hemorrhage. Similarly, maternal age, preeclampsia, and the forceps delivery listed in option c) may be risk factors for other complications but are less directly associated with hemorrhage post-delivery. Lastly, the condition of polyhydramnios, macrosomia, prolonged labor, and maternal infection, as identified in option d), can contribute to a challenging delivery but are again not among the leading causes of postpartum hemorrhage.