Low-lying placenta is a type of placenta previa, which is classified into three types: complete placenta previa, partial placenta previa, and low-lying placenta:
1. Complete placenta previa occurs when the placenta entirely covers the cervical opening.
2. Partial placenta previa involves only a part of the placenta covering the cervical opening.
3. Comparatively, low-lying placenta is the least severe among the three types of placenta previa, but expectant mothers should still not take it lightly.
So, can a low-lying placenta lead to a normal delivery?
1. After 28 weeks of pregnancy, when the placenta is attached to the lower segment of the uterus, or even when the lower edge of the placenta reaches or covers the cervical opening, and its position is lower than the presenting part of the fetus, it is called placenta previa. Placenta previa is a serious complication in the late stages of pregnancy and is a common cause of major bleeding during late pregnancy and delivery. When diagnosing placenta previa via ultrasound, it is essential to consider the gestational age.
2. In the second trimester before 28 weeks of pregnancy, the placenta occupies half of the uterine wall, increasing the likelihood of it being close to or covering the cervical opening. In the third trimester after 28 weeks, the placenta reduces to occupying one-third or one-quarter of the uterine wall. The formation and stretching of the lower uterine segment increase the distance between the cervical opening and the edge of the placenta. Therefore, a placenta initially located in the lower segment of the uterus may move upward with the uterine body and become a normally positioned placenta. Thus, many scholars suggest that if a low-lying placenta is detected via ultrasound in the second trimester, it should not be diagnosed as "placenta previa" but referred to as a "placenta previa state." Ultrasounds should be repeated every four weeks or so, with earlier ultrasounds required if there is vaginal bleeding, so that doctors can make timely and appropriate interventions.
3. If placenta previa is diagnosed and there is no vaginal bleeding or only a small amount of vaginal bleeding, the pregnancy should be extended as long as possible, up to 36 weeks, as long as the mother's safety is ensured. After 35 weeks of pregnancy, the frequency of uterine contractions increases, significantly raising the risk of bleeding from placenta previa, which increases the danger to both the mother and the fetus. Therefore, doctors will check for the maturity of the fetal lungs at 36 weeks in cases of placenta previa and choose to terminate the pregnancy via a cesarean section at the appropriate time. A cesarean section can deliver the baby quickly, followed by the prompt removal of the placenta. Uterine contractions are enhanced with medication, and bleeding from the placental detachment site in the lower uterine segment is observed directly. Accurate use of drugs or surgical methods to stop bleeding is crucial to prevent major bleeding during and after delivery.
Finally, pregnant women should ensure they rest adequately, avoid overexertion, and take care not to strain excessively when changing positions, including during bowel movements. Constipation and sexual activity should be avoided, and any sign of bleeding should prompt an immediate visit to the hospital.
