Which condition is characterized by the implantation of the placenta near or on the internal cervical os?

The condition characterized by the implantation of the placenta near or on the internal cervical os is known as placenta previa. In this situation, the placenta is positioned low in the uterus, covering the cervix either partially or fully, which can lead to complications during pregnancy and delivery.

Placenta previa is significant because it can cause serious bleeding before and during labor, making it necessary for careful management and monitoring throughout pregnancy. If the placenta is covering the cervical opening, a vaginal delivery may be unsafe, and a cesarean section is often required to safeguard the health of both the mother and the baby.

Other conditions listed, such as placenta accreta, involve the placenta attaching too deeply into the uterine wall, which poses different risks during delivery, but they do not specifically relate to the location of implantation near the cervical os as placenta previa does. Similarly, placental abruption refers to the premature separation of the placenta from the uterine wall and does not pertain to its location in relation to the cervix. Total placenta previa, while related to the definition of placenta previa, indicates a full covering of the cervical os, making it a specific type of the broader condition. Thus, the correct answer reflects the general definition and location of implantation pertinent to placenta