The diagnosis of "low location of the placenta" during pregnancy is made no earlier than 20 weeks of gestation. Before this period, the placenta can change localization, rise higher along with the growth of the uterus. However, it is important to distinguish between low placenta and placenta previa during pregnancy. Although in both cases we are talking about the place of attachment of the child's seat, the prognosis for conditions in terms of gestation, the likelihood of complications and the process of childbirth differ.
What is a "baby seat"?
A child's place is an unscientific, albeit well-established, and previously actively used in medicine name for the placenta. This is an amazing "disposable" organ: the placenta appears during the period of gestation and is excreted from the body during childbirth, when, together with the membranes of the membranes, it is called the afterbirth.
A temporary but very important organ, the placenta is needed for communication between mother and child. It develops simultaneously with the embryo and completes its formation completely by the end of the first trimester.
As a rule, the place of attachment of the placenta is on the wall or fundus of the uterus (it is located at the top, on the opposite side of the cervix and vagina). On the walls and bottom there is the most developed network of blood vessels, which means that the placenta has every opportunity to fully develop and transfer the maximum nutrients and oxygen from the maternal bloodstream to the baby.
Low placentation or low placenta during pregnancy is said if the baby's place is attached close to the cervix. If the edge of the placenta extends over the cervix or overlaps it all, this is a presentation. This condition is dangerous both by malnutrition of the child and by detachment of the placenta during labor, therefore placenta previa is an unconditional indication for operative delivery (caesarean section).
Diagnosis of low placentation or low placenta location
Quite often, the low location of the placenta during pregnancy at the beginning of the second trimester is detected on ultrasound at the first screening. At this time (if there are no other pathologies of the child's place), no measures are required, because low placentation disappears by itself as the uterus grows.
With an ultrasound scan (conventional ultrasound), a specialist may suspect or diagnose an anomaly in the location of the child's seat. At the same time, serious concern is justified if the anomaly is detected in the second half of gestation. Until mid-gestation - up to 20 weeks - the placenta migrates upward, closer to the bottom of the uterus, which is due to the active growth of the organ during this period.
According to the research of Russian specialists, only one of 10 expectant mothers, who were diagnosed with a low location of the placenta during pregnancy before 20-24 weeks, had low placentation persisting in the future.
Re-pregnancy and operative delivery by cesarean section are considered to be predisposing factors for the preservation of anomalies in the location of the placenta. The presence of a scar on the uterus is especially affected - in half of pregnant women with a history of cesarean section and low placentation or presentation of a child's place up to 20 weeks later, sufficient migration of the placenta does not occur.
However, in some cases, the placenta does not rise above 60 mm from the internal pharynx even after 20 weeks (control ultrasound in such cases is recommended for a period of 24 weeks). In a similar situation, they talk about low placentation during pregnancy. Why is it dangerous?
Low Placentation Risks
With a low location and even placenta previa, the fetus can develop normally until the end of the due period of gestation. However, the risk of pathology will still be increased.
Due to the fact that the placenta is located low, the likelihood of partial detachment of the edge of the placenta and bleeding in the second or third trimester increases. Moreover, the volume of blood discharge can be significant and pose a risk to the life of both the child and the mother. If we are talking only about low placentation during pregnancy, natural childbirth can be considered taking into account various factors - the position of the child in the uterus at 37 weeks, the size of the fetus, the exact distance from the edge of the placenta to the internal os of the cervix, concomitant pathologies, etc. from the edge of the placenta to the cervix of 20 mm or less, a cesarean section at 36 weeks is indicated.
With placenta previa, operative delivery is always indicated.
How to suspect an anomaly?
If an ultrasound examination of the uterus was not performed for some reason, then an anomaly in the location of the placenta may be suspected by some markers:
uterine bleeding at the end of the second or third trimester. Most often they are painless and provoked by physical activity, intercourse or training contractions; in later periods (after 36 weeks), low placentation or presentation can also be suspected by the position of the child - transverse, breech presentation, since the child's seat may interfere with taking a natural head-down position.
Of course, with such signs, it is necessary to do an ultrasound scan (especially with bleeding - urgently!) To determine where the placenta is, whether there is a partial detachment or other threats, and to decide on the method of delivery.
How are expectant mothers with placenta abnormalities observed?
If the low position of the placenta during pregnancy persists after 20 weeks, regular ultrasound examinations are prescribed. The edge of the placenta may still move slightly as the uterus stretches and grows, and this needs to be controlled.
If there is no overlap, including partial, and there is no spotting, a second examination is scheduled for a period of 36 weeks.
At 32 weeks, an ultrasound scan is performed:
If an overlap of the cervix was detected at 20 weeks; Women with a scar on the uterus and a low position of the child's seat - for any abnormality of the placenta.
When the cervix is closed, hospitalization is indicated after 34 weeks of pregnancy due to the risk of detachment and bleeding. If the expectant mother refuses to stay in the hospital, when bloody discharge or contractions appear, it is necessary to call an ambulance.