What characterizes placenta previa?

Placenta previa is characterized by the placenta being implanted low in the uterus, often covering the cervix either partially or completely. This can lead to complications during pregnancy and delivery, as it may cause bleeding and obstruct the birth canal. This low implantation can also impact the choice of delivery method, often necessitating a cesarean section to avoid risks to both the mother and the baby.

Other options describe conditions that do not fit the definition of placenta previa. For instance, the detachment of the placenta from the uterine wall refers to a condition known as placental abruption, which is different from placenta previa. An absence of the placenta would suggest a pregnancy that has not been established or a miscarriage, while abnormal development of the placenta can refer to various other complications such as placenta accreta but does not specifically define placenta previa. Thus, the key characteristic of placenta previa is primarily about the location of the placenta within the uterus, making low implantation the defining feature.