Increased echogenicity in amniotic fluid
Introduction
Introduction After 20 weeks of gestation or during childbirth, the placenta in the normal position is partially or completely detached from the uterine wall before the delivery of the fetus, called placental abruption. Placental abruption is a serious complication in the third trimester of pregnancy. The short-term training course is urgent and rapid. If it is not handled in time, it can endanger the mother and child. The incidence of domestic reports is 4.6 to 21 , and the incidence rate abroad is 5.1 to 23.3 . The incidence is related to whether the placenta is carefully examined after delivery. Some patients with mild placental abruption can have no obvious symptoms before labor. Only when the placenta is examined after delivery, it is found that there is clot blockage in the early exfoliation. Such patients are easily overlooked.
Cause
Cause
The cause of increased echogenicity in amniotic fluid:
(1) Causes of the disease:
After decades of research by scientists, early placental dissection and hypertension (including pregnancy-induced hypertension syndrome, essential hypertension, renal hypertension), trauma, premature rupture of membranes, age of pregnant women, smoking, use of cocaine, etc. Factors are related, and its onset may be related to the following major risk factors.
1. Hypertension: Hypertension includes pregnancy-induced hypertension syndrome (referred to as pregnancy-induced hypertension, especially severe pregnancy-induced hypertension), essential hypertension, chronic nephritis with hypertension, which are the primary causes of early exfoliation of the placenta. Some scholars have reported that the early placental ablation of hypertensive patients with gestational hypertension is five times higher than that of normal blood pressure during pregnancy. The pathogenesis is mainly caused by the occurrence of sacral hemorrhage in the sacral sacral artery of the placenta, acute atherosclerosis, causing ischemia, necrosis, rupture and hemorrhage of the distal capillary, forming a hematoma, gradually expanding, and separating the placenta from the uterine wall. It causes early exfoliation of the placenta. If a pregnant woman has a vascular lesion such as essential hypertension and complicated with pregnancy-induced hypertension, and the vascular disease is aggravated, there is more chance of early exfoliation of the placenta.
2. Mechanical factors: The abdomen is directly impacted, often the cause of early exfoliation of the placenta, such as the impact of a car, the sudden braking of a bus, the first landing on the abdominal wall, and the beating of the abdominal wall can cause early exfoliation of the placenta. External reversal to correct the fetal position is blocked and the force is too large, and early exfoliation of the placenta may occur. Amniocentesis may also cause early exfoliation of the placenta when the placenta is located in the anterior wall of the uterus. Other indirect factors such as excessive amniotic fluid, sudden discharge of amniotic fluid when the membrane is ruptured, or the first fetus delivered too fast during twin pregnancy, can cause sudden pressure drop in the uterine cavity and early exfoliation of the placenta. American research data reported that the early exfoliation of placenta caused by pregnant women's trauma accounted for 1% to 2%.
3. Smoking: Nearly 10 years of research have confirmed the association between smoking and early exfoliation of the placenta. It has been reported that smoking increases the risk of early exfoliation of the placenta by 90%, and the risk of early exfoliation of the placenta increases with the increase in the number of cigarettes per day. . Smoking causes degeneration of blood vessels and increases the fragility of capillaries. The effect of nicotine on vasoconstriction and elevated concentrations of carbon monoxide-binding protein in serum can lead to vasospasm ischemia, which induces early exfoliation of the placenta.
4. Premature rupture of membranes: Many studies at home and abroad have reported the correlation between premature rupture of membranes and early exfoliation of placenta. The risk of early exfoliation of the placenta in pregnant women with premature rupture of membranes is three times higher than that of premature rupture of membranes. The mechanism of its occurrence is unclear and may be related to chorioamnionitis after premature rupture of membranes.
5. Abuse of cocaine: It has been reported that 50 pregnant women were abused during pregnancy, and 8 of them were due to early exfoliation of the placenta. It was also reported that 112 pregnant women abused cocaine during pregnancy, resulting in 13% of early placental ablation.
6. Age and birth of pregnant women: The age of pregnant women is related to the early exfoliation of the placenta, but some scholars have reported that the birth rate is more likely to be related to the early exfoliation of the placenta than the age. As the number of births increases, the risk of early exfoliation of the placenta increases geometrically.
7. Others: The pregnant woman is in a supine or semi-recumbent position for a long time, so that the enlarged uterus compresses the inferior vena cava, hinders the venous return, and causes partial or complete placental dissection of the decidual venous congestion or rupture. The umbilical cord is too short or the umbilical cord around the neck, around the body, during the delivery process, the fetal first dew drops, the umbilical cord length is insufficient and is strongly pulled, which can also lead to early stripping of the placenta.
(2) Pathogenesis:
The pathogenesis of early exfoliation of the placenta has not been fully elucidated. In the past, it was generally considered to be related to vascular disease, mechanical factors, sudden increase in uterine venous pressure and other factors.
The main pathological change of the early exfoliation of the placenta is hemorrhage of the decidua, which forms a hematoma, which causes the placenta to peel off from the attachment. If the area of exfoliation is small, the blood will quickly coagulate after the bleeding stops, and the clinical symptoms are asymptomatic. Only the clots compress the placenta, leaving a trace on the maternal surface of the placenta, often found in the placenta after the postpartum examination; if the exfoliation area is large, continue to bleed The hematoma is formed after the placenta, and the part of the placenta is continuously enlarged. At this time, because the fetus has not been delivered, the uterus can not contract, so it can not stop bleeding, and the bleeding is increasing, which can break the edge of the placenta and pass the cervical canal along the membrane between the membrane and the uterus. Outflow, that is, revealed abruption or external bleeding. If the edge of the placenta still adheres to the wall of the uterus, or the membrane is not separated from the wall of the uterus, or the fetal head is fixed at the entrance of the pelvis, the blood can not flow out after the placenta, the hematoma gradually increases after the placenta, and the placental exfoliation surface also expands. The bottom of the palace is constantly rising, that is, conealed abruption or internal bleeding. When the accumulation of hidden hemorrhage is excessive, the blood can still rush out of the edge of the placenta and the membrane to form a mixed hemorrhage. Sometimes bleeding can enter the amniotic fluid through the amniotic membrane to become bloody amniotic fluid.
The early placenta of the recessive placenta, the blood can not flow out, the bleeding gradually increases and the hematoma is formed after the placenta. As the pressure increases, the blood is immersed in the myometrium, causing the separation of muscle fibers, breaking, denaturation, blood immersion and even the serosal layer, uterine surface. Purple freckle appears, in severe cases, the entire uterus is copper-colored, especially the placenta attachment, called uteroplacental apoplexy. At this time, the muscle fibers are impregnated with blood, and the contractile force is weakened, which may cause major bleeding after production. Sometimes blood can also penetrate into the abdominal cavity, or infiltrate into the broad ligament, fallopian tubes and so on.
Severe placental early stripping, especially in intrauterine cases, can cause coagulopathy, necrotic placental villi and decidua at the site of exfoliation, release a large amount of tissue thromboplastin into the maternal circulation, activate the coagulation system to cause DIC. Micro-thrombus formation may occur in the capillaries of organs such as lungs and kidneys, causing damage to organs. A large loss of coagulation factors such as platelets and fibrinogen eventually activates the fibrinolytic system, producing a large amount of fibrin degradation products (FDP), which in turn causes fibrinolysis and exacerbates coagulation dysfunction.
Examine
an examination
Related inspection
NST test amniocentesis laparoscopic
Clinical manifestations:
Sher (1985) classification was used in foreign countries to divide the early exfoliation of placenta into I, II and III degrees. I degree: mild, postpartum hematoma diagnosis according to placenta; II degree: intermediate type, fetal heart rate changes and clinical symptoms; III degree: severe, fetal death, IIIa, no coagulopathy, IIIb coagulopathy. China's textbooks divide it into light and heavy 2 types. Lightweight is equivalent to SherI, and heavy duty includes SherII and III degrees.
The most common typical symptom of early exfoliation of the placenta is painful vaginal bleeding, but the symptoms and signs of early exfoliation of the placenta are large.
1. Light type: mostly vaginal bleeding and mild abdominal pain, the placental stripping surface usually does not exceed 1/3 of the placenta, more common in the delivery period. The main symptoms are vaginal bleeding, the amount of bleeding is generally more, the color is dark red, may be accompanied by mild abdominal pain or abdominal pain is not obvious, the anemia sign is not significant. If it occurs during childbirth, the labor progresses faster. Abdominal examination: the uterus is soft, the contractions are intermittent, the size of the uterus is consistent with the number of weeks of pregnancy, the fetal position is clear, and the fetal heart rate is normal. If the amount of bleeding is high, the fetal heart rate may change, the tenderness is not obvious or only mild (local) Placental abruption) tenderness. After the postpartum examination of the placenta, it can be seen that there are clots and pressure marks on the maternal surface of the placenta. Sometimes the symptoms and signs are not obvious. Only when the placenta is examined after delivery, the placenta has clots and pressure marks on the maternal surface, and the placental abruption is found.
2. Severe: internal hemorrhage and mixed hemorrhage, the placental stripping surface exceeds 1/3 of the placenta, and there is a large postpartum hematoma, more common in severe pregnancy-induced hypertension. The main symptoms are sudden persistent abdominal pain and/or backache and low back pain, the degree of which varies depending on the size of the peeling surface and the amount of blood accumulated after the placenta. The more blood, the more severe the pain. In severe cases, nausea and vomiting may occur, and signs of shock such as paleness, sweating, weak pulse, and decreased blood pressure may occur. There may be no vaginal bleeding or only a small amount of vaginal bleeding, and the degree of anemia is not consistent with the amount of external bleeding. Abdominal examination: palpation of the uterus is as hard as a plate, with tenderness, especially at the place where the placenta is attached. If the placenta is attached to the posterior wall of the uterus, the uterine tenderness is not obvious. The uterus is larger than the gestational week, and with the increase of the hematoma after the placenta, the fundus is increased and the tenderness is more obvious. Occasionally, the uterus is in a hypertonic state, and the interval is not very relaxed, so the fetal position is unclear. If the placental exfoliation surface exceeds 1/2 or more of the placenta, the fetus will die due to severe hypoxia, so the fetal heart of the severe patient has disappeared.
diagnosis:
1. Diagnosis basis:
(1) may have a history of trauma, history of vascular disease.
(2) There is vaginal bleeding accompanied by abdominal pain.
(3) The uterus has limited tenderness and tenderness, and it is in a hypertonic state, and the fundus is elevated.
(4) The fetal heart is weakened or even disappeared.
(5) Ultrasound examination showed a dark area between the uterine wall and the placenta. The echo in the amniotic fluid increased and the villus board protruded into the amniotic cavity.
(6) Blood protein is reduced, and coagulation dysfunction may occur.
(7) postpartum examination of the placenta can be seen on the maternal surface of the placenta with clots and pressure marks.
2. Classification diagnosis:
(1) Light placental abruption: the placental stripping surface usually does not exceed 1/3 of the placenta area, manifested as vaginal bleeding, anemia signs are not significant, mild abdominal pain or no abdominal pain, intermittent contractions, clear fetal position, fetal heart rate More normal, sometimes symptoms and signs are not obvious, only found in the placenta maternal surface clots and pressure marks.
(2) severe placental abruption: the placental stripping surface exceeds 1/3 of the placenta area, showing abdominal pain is severe and continuous, no vaginal bleeding or a small amount of vaginal bleeding, the degree of anemia is not consistent with external bleeding, the uterus is as hard as a plate, tenderness, There is no contraction, the fetal position is unclear, the sheep is bloody, and the fetal heart can disappear when the condition is serious.
3. Attention should be paid to the cause of the disease: those with pregnancy-induced hypertension, especially those with moderate or severe pregnancy-induced hypertension, are prone to early exfoliation of the placenta. There are reports that 40.5% of the early exfoliation of pregnancy-pregnant women with pregnancy-induced hypertension, and 14.8% of those with trauma. The author believes that pregnancy-induced hypertension associated with fetal growth restriction and anemia are more likely to occur early exfoliation of the placenta, should be noted.
4. According to the comprehensive analysis of clinical symptoms and signs: most cases of early exfoliation of light placenta may start with a small amount of painless vaginal bleeding, and then develop into painful vaginal bleeding, so it is necessary to combine the medical history to closely observe vaginal bleeding and contractions. Changes in nature, fetal heart rate, combined with auxiliary examination to make early diagnosis and treatment. The symptoms and signs of early exfoliation of severe placenta are typical. There is no difficulty in diagnosis, but the severity should be judged. When the uterus bleeds, the skin and mucous membranes have bleeding. This often indicates the presence of DIC, which should be especially vigilant.
5. Placenta attached to the posterior wall of the uterus for early stripping of the placenta: this is most easily overlooked, especially in the early stages. Its characteristics are that in the third trimester of pregnancy, with or without vaginal bleeding, as long as the uterus tension is unknown, but not too much amniotic fluid, and not in labor, is not a hypertonic uterus contraction, especially with pregnancy-induced hypertension Those with fetal growth restriction, although the fetal heart is still normal, must consider the possibility of early placental exfoliation of the placenta attached to the posterior wall of the uterus. It can be diagnosed by B-mode ultrasound and fetal heart monitoring.
Diagnosis
Differential diagnosis
Increased echogenicity in amniotic fluid increases confusing symptoms:
In late pregnancy, in addition to placental abruption, there are still placenta previa, uterine rupture and bleeding of cervical lesions, etc., should be identified, especially in the identification of placenta previa and uterine rupture.
1, placenta previa: light placental abruption, can also be painless vaginal bleeding, signs are not obvious, B-mode ultrasound to determine the lower edge of the placenta, you can confirm the diagnosis. Placental abruption on the posterior wall of the uterus, abdominal signs are not obvious, it is not easy to distinguish from the placenta previa, B-ultrasound can also be identified. The clinical manifestations of severe placental abruption are very typical and it is not difficult to distinguish from placenta previa.
2, aura uterus rupture: often occurs in the process of childbirth, the emergence of strong contractions, lower abdominal pain refused to press, irritability, a small amount of vaginal bleeding, fetal distress signs. The above clinical manifestations are more difficult to distinguish from severe placental abruption. However, there are many uterine ruptures in the aura, uterine tube obstruction or cesarean section history, examination can be found in the uterus pathological retraction ring, catheterization has gross hematuria, etc., and placental abruption is often a patient with severe pregnancy-induced hypertension, check the uterus The plate is hard.
Early exfoliation of the placenta is mainly differentiated from the placenta previa and the uterine rupture of the aura.
