stillbirth in utero

Introduction

Introduction to the fetal death palace The stillbirth refers to the death of the fetus in the womb after 20 weeks of gestation. Serious fetal malformations, high blood pressure caused by pregnancy convulsions, early water breakage caused by intrauterine infection, Mediterranean anemia, bacterial infections and other diseases are common causes of fetal death. Within two weeks of the death of the fetus, it is generally possible to give birth naturally. Choosing to wait for natural delivery is not a great risk to the health of the pregnant woman. If the pregnant woman chooses to wait for the natural delivery, but there is still no movement after two weeks, it is best to artificially induce labor because There is a risk of blood clotting for a long time. basic knowledge The proportion of the disease: about 0.02% - 0.04% of pregnant women Susceptible population: pregnant women Mode of infection: non-infectious Complications: uterine contraction, postpartum hemorrhage, diffuse intravascular coagulation

Cause

Fetal death

1, common factors

(1) Severe fetal malformation: stillbirth or structural malformation caused by hereditary or environmental factors or unknown factors.

(2) The high blood pressure of pregnant women causes the fetus to not get enough nutrients and oxygen supply.

(3) Hypertension causes pregnancy convulsions, causing death of pregnant women and fetuses.

(4) Before the delivery, the placenta is partially or completely exfoliated early, and the fetus is deprived of oxygen due to excessive maternal blood loss. The situation can endanger the life of the mother and the fetus.

(5) Fetal growth is limited: fetuses that are too small or slow to grow are at higher risk of suffocation (hypoxia) or unknown factors, whether they are prenatal or bifurcation.

(6) Early water breakage causes intrauterine infection.

(7) Mediterranean anemia or rhesus monkey disease.

(8) Undetected or poorly controlled gestational diabetes.

(9) Bacterial infection: Toxoplasmosis, Streptococcus B, and German rubella are important culprit in fetal death between 24 and 27 weeks.

2, other rare reasons

(1) Difficult to produce.

(2) Umbilical cord factors.

(3) The baby is traumatized.

(4) Overdue pregnancy: The pregnancy period is longer than 42 weeks.

Prevention

Fetal death prevention

In 1950, Weiner et al. first discovered that Rh-negative stillbirths caused coagulopathy. Later, some scholars showed that fibrinogen increased from 3 g/L (300 mg/dl) to 4.5 g during non-pregnancy during normal pregnancy. /L (450mg/dl), coagulation factors I, VII, VIII, IX and X increased, but fetal death occurred after 20 weeks of pregnancy, fetal tissue thromboplastin stimulated the extracorporeal blood coagulation system caused by extensive microthrombus in the blood vessels Formation, leading to clotting factor consumption, mainly V, VIII fibrinogen, prothrombin and platelet secondary fibrinolysis, clotting, hemorrhage and tissue necrosis and other DIC changes, low fibrinogenemia and intrauterine stillbirth retention time In the 4 weeks after the death of the fetus, almost no coagulation system disease was observed; after 4 weeks, 25% of the pregnant women developed hypofibrinemia, and the plasma fibrinogen level slowly decreased linearly (25-85 mg/(dl·week)) Until the delivery, it usually returns to normal 48 hours after delivery, and can be prevented by low-dose heparin before the stillbirth is cleared.

With the continuous advancement of medical technology, it is now possible to accurately and timely diagnose the fetal death, reduce the occurrence of maternal complications, combined with regular prenatal care, can prevent fetal death is also possible, confirm the fetus in the palace There is a risk of sudden death, proper and timely obstetric intervention in the third trimester of pregnancy, and complete neonatal rescue facilities can reduce intrauterine mortality, because 85% of stillbirths are caused by fetal fatal malformations and hypoxia. So this is the key to predictive evaluation.

1. The mother's medical history: a careful understanding of the medical history of pregnant women, according to the survey of pregnant women's medical and social, economic status, divided into high-risk, low-risk groups, the intrauterine mortality rate of the fetus is 5.4% and 1.3%, respectively, therefore, strengthen the high-risk pregnant women The monitoring can also reduce the death of a part of the fetus.

2, fetal movement: is the most simple, economical, convenient monitoring means, can be monitored by pregnant women, if 12h fetal movement less than 10 times or more than 50% per day, should consider fetal distress, in high-risk pregnancy, placental function Decreased can cause fetal movement loss before the change of fetal heart rate (must be excluded from sedatives or drugs such as magnesium sulfate). If the fetal activity is found to increase sharply and then stop, it often indicates acute intrauterine hypoxia and death, mostly due to umbilical cord Pressure, caused by placental abruption.

3, pregnancy map: In 1972, Sweden first used pregnancy map to observe the intrauterine growth of the fetus, it dynamically observed the weight of the pregnant woman, abdominal circumference, Gonggao and other indicators, timely detection of fetal developmental abnormalities, such as IUGR, deformed children, amniotic fluid Too much/too few, etc., generally start recording at 16 weeks of gestation. If it grows gradually within the normal range, it means that the fetal development is normal, 84%~86% can deliver normal weight, if the parameters are 2 or 3 times in a warning. The zone stops unchanged, the growth is too slow or too fast, and all of them suggest fetal abnormalities, and further ultrasound or biochemical tests are needed.

4, biochemical examination

(1) Estradiol (E3) in maternal urine: it continues to rise during pregnancy, but begins to decline within 24 to 48 hours of fetal death, because most of the precursors of E3 are dehydroepiandrosterone sulfate and 16-hydroxydehydrogenation. Epirubicinone sulfate is derived from functional fetal kidney and fetal liver. If the 24hE3 content is <10~12mg, or 35% sharply decreased, it indicates that the placental function is decreased and the perinatal mortality is increased; E3<6mg Or a sharp decrease of more than 50%, suggesting that the placental function is significantly reduced, the fetus may have died, in high-risk pregnant women, low E3 levels have up to 75% of intrauterine deaths, but the false positive rate is high (44%), The false negative rate is low (1%), so E3 quantitative determination is more useful in fetal prenatal monitoring than in the diagnosis of fetal death, but due to the difficulty in collecting 24h urine samples, and E3 production is susceptible to exogenous steroids, so currently Has been replaced by other methods.

(2) Hormone determination: The determination of hormones is closely related to gestational age, and it is best to give continuous measurement to improve the accuracy of prediction. However, after 9 weeks, B-ultrasound can predict pregnancy outcome more accurately than hormones. In addition, AFP and hCG Combining B-ultrasound can initially screen some congenital malformations such as chromosomal abnormalities and nervous system defects.

(3) amniocentesis: high-risk pregnant women with advanced age, history of malformation, family history of hereditary diseases, abnormal serum screening, etc., 16 to 20 weeks of amniocentesis to exclude chromosomal abnormalities, reliability of 96%, and other villus biopsy Surgery (7 to 9 weeks of pregnancy), the diagnostic accuracy of 99.6%; umbilical cord puncture (18 ~ 22 weeks), in addition to chromosomal diseases can also check blood system diseases, infection and determine whether there is intrauterine hypoxia.

Ultrasound assessment, ultrasonography is an important method of prenatal monitoring. It can evaluate the anatomy, growth and hemodynamics of the fetus. If an abnormality can be detected, it can be used as soon as possible to reduce the occurrence of stillbirth. Ultrasound imaging (B-ultrasound), M-type diagnostic method (check fetal heart structure), Doppler flow imaging and new Doppler energy imaging, fetal volume imaging, three-dimensional imaging, tissue harmonic display For example, Doppler tissue imaging, etc., can make most of the abnormalities and developmental conditions of the fetus can be displayed, which can greatly reduce the occurrence of stillbirth. In addition to the fetal malformation, ultrasound can also evaluate the fetus through biophysical scoring. Response to hypoxia, including fetal heart rate response (NST), muscle tone (FT), body movement (FM), respiratory-like movement (FBM), amniotic fluid volume (AFV), the first 4 items of the central nervous system Regulation, fetal heart rate central functionalization time is late, most sensitive to hypoxia, mild hypoxia changes, and muscle tension is not sensitive to hypoxia, when the function of oxygen deficiency is the latest, when the muscle tension is 0, The perinatal mortality rate reached 42. 8%, the decrease in amniotic fluid indicates intrauterine chronic hypoxia, and often accompanied by IUGR, fetal malformation, making the umbilical cord susceptible to compression. If the maximum amniotic fluid depth is <1cm, the perinatal mortality rate is 18.75%, except for fatal malformation. The mortality rate is 10.94%. Umbilical blood flow ultrasound Doppler-S/D is also an important component of ultrasound evaluation. When S/D4, the incidence of IUGR is 67.7%, and the perinatal mortality rate is 30.3. %, the main reason is the umbilical cord abnormality (64.5%), often tightly entangled, so that the umbilical cord blood flow is blocked. If the NSF shows no reaction at this time, the fetus is extremely dangerous.

Fetal heart monitoring, NST and CST are difficult to determine the predictive value of stillbirth. Clinically, too many interventions are given due to abnormal results. However, fetal heart rate variability still has its value in high-risk pregnancies. Rochard reports that 76 cases of NST are normal. There were no stillbirths in the group, and 13 of the 49 abnormalities died (27%). In short, the NST false negative rate (NST reactive, and fetal death) <1%, false positive rate (NST is not reactive, and Fetal survival is 70% to 90%, CST can improve the accuracy of predicting fetal death, 80% to 90% of non-reactive NST, its CST is normal, it is lower than NST false positive rate (30% to 60%) .

Complication

Intrauterine complications Complications, uterine contraction, postpartum hemorrhage, diffuse intravascular coagulation

Those with long-term fetal death may be fatigued, loss of appetite, abdomen falling, postpartum hemorrhage or diffuse intravascular coagulation.

Symptom

Fetal death intrauterine symptoms Common symptoms Fetal heart sound disappears (no... Fetal intrauterine asphyxia weight loss

symptom:

The most common complaints of pregnant women after fetal death are: 1. The fetal movement disappears; 2. The weight does not increase or decrease; 3. The breast retracts; 4. Others: If you feel unwell, have bloody or watery vaginal discharge, and have a foul smell in your mouth. Wait.

Signs:

1. Regular follow-up examination revealed that the uterus did not increase with the increase of gestational age.

2, the fetal heart has not heard.

3, fetal movements are not yet.

4, the palpation of the abdomen and the elastic, strong carcass part.

After the death of the fetus, the pregnant woman consciously stops fetal movement, the uterus stops growing, and the fetal heart is not heard during the examination. The uterus is smaller than the gestational week, and can be considered as a stillbirth. B-ultrasound can be confirmed.

According to the conscious fetal movement stop, the uterus stops growing, the fetal heart is not heard, the uterus is smaller than the gestational week, and can be considered as stillbirth. The commonly used auxiliary examinations are: B-mode ultrasound found that fetal heart rate and fetal movement disappeared is a reliable basis for the diagnosis of stillbirth. If the death is too long, the skull collapses, the skull overlaps, and the bag is deformed, which can be diagnosed as stillbirth: Doppler fetal heart rate can not help the fetal heart can help confirm the diagnosis. In the third trimester of pregnancy, the urinary triol content of pregnant women is less than 3mg. (Measured in the normal range not long ago) also suggested that the fetus may die, and the alpha-fetoprotein value of amniotic fluid was significantly increased.

Examine

Inspection in the fetal death

1, before childbirth

(1) Peripheral smear examination of fetal red blood cells (Kleihauer-betke test).

(2) Cervical secretion culture.

(3) Urine virus isolation/culture.

(4) Separation of maternal blood virus, examination of Toxoplasma gondii, etc.

(5) Indirect anti-globulin test (indirect coombs).

(6) Fasting blood glucose or glycosyl hemoglobin.

(7) Anticardiolipin antibodies, antigen antibodies.

(8) Lupus anticoagulant.

(9) Blood routine.

(10) If the death time exceeds 4 weeks, fibrinogen and platelets are measured weekly until delivery.

(11) amniocentesis: karyotype analysis and virus, aerobic, anaerobic culture.

2, after childbirth

(1) Mother: Assessment of coagulation function (platelets, APTT, fibrin)

(2) Placenta:

1 Child and mother face bacterial culture.

2 Placental tissue was isolated for virus karyotype analysis.

3 placental histopathological examination, such as contoured placenta, placental abruption, abnormal umbilical cord attachment and abnormal placental size.

4 cord blood culture.

(3) Fetus:

1 throat, outer ear, anus bacterial culture.

2 fetal autopsy.

Film degree exam

1, X-ray inspection

It is used to diagnose the fetal death in the earliest in 1922. In the early stage of fetal death, X-ray examination can be found without any abnormality; after the fetal deformation, there are 4 main X-ray signs in the abdomen, in which the formation of gas is unique. Reliable X-ray diagnosis signs.

(1) Gas formation: This phenomenon occurs 6 hours to 10 days after the death of the fetus. The gas accumulates in the fetal large blood vessels or soft tissues. This phenomenon is reported in 13% to 84% of cases. It occurs only in late fetal death, sometimes Diagnosis may be more difficult if it is mistaken for the mother's excessive gas accumulation.

(2) The halo around the fetal head: it is the first sign of fetal death within 48 hours. Due to the accumulation of fetal decidual submucosal fluid, the scalp lower fat is formed by halo, which may occur in 38% to 90% of cases. Sometimes it must be differentiated from fetal edema.

(3) Fetal cranial collapse: more than 7 days after death, almost 10 days after the collapse of the skull plate, it is mainly due to the reduction of intracranial pressure after fetal death, resulting in deformation of the skull.

(4) Angle of the spine: After the death of the fetus, the tension of the spine is weakened or disappeared, and the phenomenon of backward angulation occurs.

2, ultrasound examination

The fetal death time is different, the ultrasound examination is different, the death time is shorter, only the fetal heartbeat disappears, the blood flow of various organs in the fetus, the blood flow of the umbilical cord stops, the body tension and bone, the echo of the subcutaneous tissue is normal, and the echogenic area of the amniotic fluid No abnormal changes, long death time, ultrasound-induced fetal infiltration phenomenon similar to radiological imaging, showing fetal skull strong echo ring, skull overlap, deformation; fetal subcutaneous fluid accumulation caused by scalp edema and systemic edema performance; The serosal cavity, such as the thoracic cavity, the abdominal cavity; the intestines in the abdominal cavity are dilated and can be seen with irregular strong echoes; a small amount of gas accumulation may also not produce a shadow of the sound image. If the stillbirth is in the palace, further dip is deformed, and its outline becomes blurred, possibly It will be difficult to identify. At this time, it is necessary to guard against the occurrence of disseminated intravascular coagulation (DIC) in pregnant women. Occasionally, ultrasound examination can also detect the cause of death of the fetus, such as multiple deformities.

Diagnosis

Intrauterine diagnosis and identification

After the death of the fetus, the pregnant woman consciously stops fetal movement, the breast swelling disappears, the uterus does not continue to increase, the weight decreases, and the fetal heart disappears, then the stillbirth may be considered. B-mode ultrasound examination suggests fetal movement, fetal heart loss, and sometimes the fetal head has been deformed to confirm the diagnosis. Most of the stillbirths can be discharged by themselves. If they are not discharged after 3 weeks of death, the degenerated placenta and amniotic fluid release thromboplastin into the maternal blood circulation, causing disseminated intravascular coagulation (DIC).

Diagnose based on

1. The fetal movement stops, the fetal heart disappears, and the size of the uterus does not match the corresponding pregnancy month.

2, ultrasound examination showed no fetal heart, fetal movement, skull overlap.

3, X-ray examination: the fetal spine is bent at an angle.

4, amniotic fluid alpha fetoprotein significantly increased.

5. Urinary estriol content <3mg/24 hours.

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