The placenta is an important organ for expectant mothers to deliver nutrients and oxygen to their babies during pregnancy. At the same time, it also shoulders the function of transporting the baby's metabolic waste out and then metabolizing it through the mother. It is precisely because the placenta has such an important function, so when the expectant mother is examined in ultrasound, the doctor will not only check the growth and development of the fetus, but also check the situation of the placenta.
In general, the placenta can attach to the base, anterior, posterior, and lateral walls of the uterus. The normal placenta should be located away from the inner cervical opening. When ultrasonography suggests that the lower edge of the placenta is less than 20 mm from the inside of the cervix, or that placental tissue covers the inside of the cervix, it is considered to be low.
However, the position of the placenta is not set in stone, and as the gestational age increases, the uterus gradually enlarges and most placenta positions gradually move upwards. Studies have shown that about 90% of pregnant women have a placenta previa found on ultrasonography before 20 weeks of pregnancy, which will grow to a normal position before death. Among them, the placenta previa of the anterior wall of the uterus is higher than that of the placenta previa of the posterior wall of the uterus, and the probability of growing up later is higher. However, the anterior placenta previa is more likely to occur prenatal hemorrhage.
Therefore, before 28 weeks of pregnancy, when the placenta position is found to be low, the expectant mother does not have to worry, and the situation at this time can only be called "placenta previa state". Only after 28 weeks of pregnancy, the placenta is still in a low state, it can be called "placenta previa".
Placenta is low, the most typical manifestation of which is that expectant mothers will have repeated vaginal bleeding without cause and pain.
If the placenta is placed low in the first trimester, painless vaginal bleeding is predisposed. This amount of bleeding is generally less and normally does not exceed menstrual flow. Some people bleed while lying down, and the blood accumulates at the top of the vagina and the posterior vault without flowing out. When she gets up and moves, the accumulated blood will flow out along the vaginal opening.
Vaginal bleeding may also occur if the placenta is low in the second trimester, but this is generally less common.
At present, some scholars believe that when the placenta is attached to the lower part of the uterus and the position is too low, the blood supply here is relatively weak, and the placenta shrinks, which in turn will make the placenta grow and develop compensatoryly in other parts. It is easy to form conditions such as wheeled placenta and sail placenta. This type of placenta does not affect the development of the baby in the belly, but there are also a very small number of people, because they have vascular preposition, which is very dangerous for the fetus born vaginally.
If in the third trimester, the placenta is still covered or close to the inner cervical opening, then it will be recognized as "placenta previa". Placenta previa is the main cause of prenatal bleeding in the third trimester, and its severity will change with the progression of pregnancy and labor, and even threaten the life safety of the mother and baby.
As a result, many expectant mothers, when they are detected to have a low placenta, stay in bed. Some people will even raise their butts while sleeping, hoping that this will promote the placenta to grow faster. In fact, this is not only not helpful to the mother, but also not conducive to physical health.
Currently, no method or drug has been shown to improve or correct placental position. If you stay in bed for a long time during pregnancy, it will also aggravate the formation of blood clots, endangering the health of the mother.
For expectant mothers who are only on ultrasonography who indicate low placental position but do not have vaginal bleeding, this condition can be performed with general routine activities and exercises. However, it is necessary to pay attention to the fact that the movement is not too large, and if there is vaginal bleeding, it is necessary to seek medical attention in time.
For those expectant mothers whose ultrasonography shows that the placenta completely covers the inner cervical opening, or who do not completely cover the inner cervical opening but will have repeated vaginal bleeding, they should be prohibited from having intercourse. In addition, such expectant mothers also need to pay attention to prevent constipation, do not lift or carry heavy objects, in order to prevent increased abdominal pressure, resulting in vaginal bleeding or placental abruption.
Finally, I want to tell expectant mothers whose pre-pregnancy ultrasound is a low placental state, don't worry too much, the vast majority of people, the placenta will grow to a normal position in the third trimester. If the expectant mother still fails to grow the placenta to the end and is diagnosed with a placenta previa, she needs to choose the caesarean section delivery method according to the doctor's recommendation.