The normal attachment of the placenta is to the posterior, anterior, or lateral wall of the uterine body. If the placenta is attached to the lower segment of the uterus or covers the internal os of the cervix, and is positioned lower than the presenting part of the fetus, it is called placenta previa. This disease is one of the main causes of bleeding in the second and third trimesters of pregnancy and is also a serious complication during pregnancy. If handled improperly or not in time, the life safety of mother and baby will be endangered.
Symptoms of placenta previa are characterized by painless vaginal bleeding that often recurs. There is no sign before bleeding, and it often occurs in the middle of the night, and the patient wakes up due to vaginal bleeding. Generally speaking, the earlier the first bleeding occurs (around 28 weeks of pregnancy or earlier), the more frequent and larger the bleeding will be. Sometimes heavy bleeding can put patients into a state of shock.
The cause of placenta previa is not yet clear, but it may be related to endometrial damage caused by endometritis or intrapartum infection, dilation and curettage, multipartum, cesarean section and other factors. Therefore, good contraception, preventing multiple fetuses, and avoiding unnecessary uterine evacuation are the main principles to prevent placenta previa. In particular, we must avoid multiple uterine evacuation or intrauterine infection, let alone illegal abortion. The B-ultrasound in the second trimester revealed that the placenta was located low, about 30% beyond the internal cervical os. Place the placenta. Therefore, in the absence of bleeding symptoms, if the placenta is found to be in a low position through B-ultrasound examination before 34 weeks of pregnancy, placenta previa generally cannot be diagnosed.
What are the dangers of placenta previa?
Pregnancy with placenta previa not only increases the risk of severe bleeding during pregnancy, but also increases the risk of labor and postpartum hemorrhage.
First, after your baby is delivered by caesarean section, the obstetrician will deliver the placenta and inject you with oxytocin (or other uterine contraction drugs) to make your uterine muscles contract and help stop bleeding where the placenta is. Comes with. But if it is placenta previa, the placenta is attached to the lower part of the uterus, and the contraction force there is not as strong as the upper part of the uterus. The contraction force is weak and cannot effectively stop bleeding, causing postpartum hemorrhage. bleeding.
Secondly, if you have placenta previa, the placenta is more likely to implant too deeply into the myometrium (placenta accreta) so that it cannot easily separate during delivery. Placenta accreta occurs in only 1 in 2,500 births, but occurs in 10 cases of placenta previa. Placenta accreta can cause very severe bleeding and may sometimes require a hysterectomy to stop the bleeding and a blood transfusion.
Finally, women with placenta previa are more likely to have low-birth-weight babies, mostly because the babies are born earlier, but also partly because of intrauterine growth restriction, and the risk is slightly higher if the mother has placenta previa.
What are the precautions for placenta previa?
1. Pregnant women should reduce their activities and rest in the left lying position. If you experience symptoms such as abdominal pain or bleeding, please seek medical attention immediately.
2. Avoid violent defecation, frequent coughing, squatting and other activities that increase abdominal pressure. Avoid stimulating the abdomen with your hands. Be gentle when changing positions.
3. Keep the vulva clean, put sanitary napkins on the perineum, and change underwear frequently to prevent infection.
4. The diet should be nutritious and comprehensive. Eating more foods high in iron, such as jujubes, lean meats, animal livers, etc., can prevent anemia. If you are bedridden for a long time, you should increase your intake of vegetables and fruits to avoid constipation and develop the habit of regular bowel movements.
5. People who are bedridden for a long time should exercise their limbs appropriately. Family members can help massage the lower limbs to prevent muscle atrophy and thrombosis. At the same time, perform deep breathing exercises every day to exercise lung function and prevent the occurrence of pneumonia.
6. Perform fetal self-monitoring and count fetal movements.