Premature rupture of membranes

Introduction to premature rupture of membranes Premature rupture of membrane (PROM) refers to the natural rupture of the membrane before delivery. Premature rupture of membranes at gestational age <37 weeks of gestation, also known as preterm premature rupture of premature rupture of membranes (PPROM) is the most common complication of perinatal period, which can be used for maternal, fetal and Neonatal causes serious adverse consequences, premature rupture of membranes can lead to increased preterm birth rate, increased perinatal mortality, intrauterine infection rate and puer infection rate are elevated, premature rupture of membranes are: trauma, cervical Mouth relaxation, ascending infection of genital pathogenic microorganisms, mycoplasma infection, increased amniocenteal pressure, poor connection between the first exposed part of the fetus and the pelvic entrance, poor membrane development, and lack of copper and zinc trace elements in pregnant women. basic knowledge Probability ratio: about 10% of maternal morbidity Susceptible population: pregnant women Mode of infection: non-infectious Complications: sepsis neonatal necrotizing enterocolitis

Cause of premature rupture of membranes

Fetal membrane dysplasia (15%):

There are many reasons. In addition to the factors of the fetal membrane itself, vitamin C deficiency in pregnant women in early pregnancy, copper deficiency and smoking in pregnant women are related to fetal membrane dysplasia.

Infection factor (18%):

Premature rupture of membranes leads to uterine infection is the causal relationship between traditional premature rupture of membranes and infection. In recent years, it has been widely recognized that infection and premature rupture of membranes are causal, and infection is the most important cause of premature rupture of membranes. .

Cervical dysfunction (15%):

In the non-pregnant state, the internal cervix can be expanded to 8.0 without resistance, which can diagnose cervical dysfunction. Cervical dysfunction is mainly characterized by internal stagnation and isthmus deficiency.

Abnormal intrauterine pressure (15%):

Uneven pressure in the uterine cavity is common in the head basin and the abnormal fetal position. Intrauterine pressure is too common in twin pregnancy, excessive amniotic fluid, severe cough and difficulty in defecation.

Trauma and mechanical stimulation (20%):

Mainly divided into iatrogenic and non-iatrogenic two types, non-medical common is the sexual activity in the third trimester of pregnancy, iatrogenic includes multiple amniocentesis, multiple vaginal examination and stripping induced labor.

Pathogenesis

1. Fetal membrane dysplasia

The normal membrane has epithelial-fibrotic maturation or metaplasia, and finally evolves into a membrane with certain elasticity and tensile strength. The membrane dysplasia mainly refers to the abnormal development of the amniotic layer and chorion layer of the membrane, while the type III glue The reduction in quality is important for premature rupture of membranes.

2. Cervical dysfunction

At present, there are many studies on the premature rupture of membranes caused by infection, and the mechanism is complicated. The following two points are summarized: 1 bacterial and bacterial inflammation destroys the structure of the membrane: bacteria itself and bacteria-induced inflammatory processes can produce a large number of enzymes, especially Glial enzymes and metalloproteinases can destroy the gelatinous membrane of the membrane, and finally lead to the decrease of tensile strength and elasticity of the amniotic membrane; 2 induce uterine contraction, increase the pressure in the amniotic cavity: the mechanism of inducing uterine contraction is mainly divided into bacteria itself. The product and bacteria-induced inflammatory reaction process of the mother. The bacteria itself mainly refers to the phospholipase A2 produced by the broken or lysed cell wall, which can induce contractions. The mechanism of uterine contraction caused by maternal inflammatory reaction is relatively complicated: Immune cells that respond to immune responses produce interleukin-like cytokines, interleukins can induce contractions; inflammatory mediators involved in the inflammatory process such as arachidonic acid systems produce prostaglandins such as PGE2 and PGF2, which induce strong uterine contractions.

3. The membrane is stretched

As the pregnancy progresses, the uterus enlarges, the intrauterine pressure increases, the cervix can not withstand the gradually increasing normal pressure and expand, and the membrane also extends to the external cervix or even the vagina to form the anterior amniotic sac, the diameter of the anterior amniotic sac. As the line gradually increases, the tensile force of the film is increased, the film is stretched, and finally breaks beyond the elastic strength of the film.

4. Intrauterine pressure abnormalities

Including intrauterine pressure unevenness and excessive intrauterine pressure.

Premature rupture of membranes

Premature rupture of membranes is a common complication of obstetrics, which can lead to prenatal and postnatal infections in mothers and children, affecting fetal maturity, increasing the incidence and mortality of perinatal children, preventing and actively treating premature rupture of membranes can effectively improve the prognosis of mothers and children. According to the vaginal fluid pH test, it is alkaline, and it can often diagnose premature rupture of membranes. When the diagnosis is unknown, it can be diagnosed by corresponding auxiliary examination such as smear examination of vaginal fluid, due to the occurrence of fetal membranes in different gestational weeks. Premature rupture, the principle of treatment is different, generally 28 to 35 weeks of pregnancy, when the condition of the fetus is allowed to actively prevent the fetus, and promote the maturity of the fetus, more than 35 weeks of pregnancy, can make it self-delivery.

Premature rupture of membranes Complications sepsis neonatal necrotizing enterocolitis

The main complications are infections including maternal uterine pelvic and systemic infections and fetal lung infections, sepsis and enterocolitis.

Symptoms of premature rupture of membranes Common symptoms Premature rupture of membranes of the amniotic cavity is inevitable premature fetal position

Symptom

Sudden vaginal discharge with or without various reasons, the amount of drainage can be more or less, the drainage is usually continuous, the duration is not equal, the amount of the beginning is more and then gradually reduced, a small amount of intermittent drainage, vaginal discharge usually It is related to the change of the position of the pregnant woman and the activity.

2. Signs

Pregnant women in the supine position may see fluid outflow from the vaginal opening, or there may be no liquid outflow; if there is no fluid outflow, when the anus is checked, the vagina is applied to the vagina, the fetal head is pushed up, the bottom of the palace is pressed, or the pregnant woman is in a position to change the body. The vaginal opening is out. Note that after these auxiliary operations, there may still be no fluid outflow. The liquid flowing out is usually thin and may be mixed with meconium or fetal fat. Emergency hospitalized patients may bring underwear, sanitary napkins or toilet paper to the hospital and should be carefully examined.

Premature rupture of membranes

1. pH detection of vaginal discharge

The pH of amniotic fluid is >7.0, the pH of vaginal secretions is 4.5-5.5. The pH of the liquid in the vagina is measured by litmus paper. If the pH value is >7.0, the premature rupture of the membrane is not performed, and <7.0 is not diagnosed as premature rupture of the membrane. However, the following items should be noted when making the diagnosis: 1 The pH value of the blood>7.0 will cause false positive results and must be differentiated from amniotic fluid; 2 Most physicians or midwives use test paper to measure the pH of the vaginal opening, especially the liquid at the posterior junction. Value, if the amniotic fluid is less or no amniotic fluid out during the test, it will cause false negative results; 3 according to the above vaginal secretions and amniotic fluid pH, 1ml vaginal secretions and 10ml amniotic fluid mixed, the theoretical pH of the mixture <6.0, Therefore, it is best to measure the liquid pH of the vaginal posterior iliac crest or the cervix outlet when measuring; 4 pay attention to the fetal fat and meconium composition in the vaginal effluent.

2. Vaginal liquid smear

The difference between amniotic fluid and vaginal secretion is that the inorganic salt in the amniotic fluid is the main component. At the same time, the amniotic fluid contains some fetal components such as the cells of the fetus, and the vaginal secretion contains a large amount of protein, and the liquid smear which flows out of the posterior vagina or the cervix. After the smear, the following examinations are helpful for diagnosis. After the smear is slowly dried, the dentate crystals or the snapdragon-like crystals can be diagnosed to diagnose the premature rupture of the membrane; the smear is heated on an ethanol lamp for 30 s, such as white. Or gray-white inorganic salt crystals, premature rupture of membranes, vaginal secretions are usually brown or black charred protein; smear for Sudan III staining, orange-red fetal sebaceous gland cells can be seen in amniotic fluid.

3. Vaginal speculum examination

Pre-existing routine disinfection, see the presence of the Qianlong sheep pool and more than 3ml can be diagnosed; contractions or compression of the fundus, amniotic fluid out of the cervix, can also make a diagnosis.

4. Ultrasound examination

B-ultrasound diagnosis of premature rupture of membranes mainly assists in the diagnosis of amniotic fluid volume and amniotic fluid distribution by B-ultrasound. If it is significantly reduced compared with the amount of amniotic fluid in recent or recent days, it can help diagnose premature rupture of membranes; amniotic fluid The size distribution limit, such as the gap between the first big sheep pool and the second big sheep pool line, can help diagnose the premature rupture of membranes.

5. Examination of other components of amniotic fluid

Amniotic fluid contains a large number of fetal, cytokines secreted by the membrane or decidua, and the cytokines of vaginal secretions are detected by various methods. It is helpful for the diagnosis of premature rupture of membranes. Commonly, there are alpha-fetoprotein, fetal fibrosis. Protein and insulin-like growth factor binding protein-1, these factors usually require enzyme-linked immunosorbent assays, which are relatively cumbersome and need to be further simplified for promotion.

Diagnosis and diagnosis of premature rupture of membranes

diagnosis

Diagnosis can be made based on clinical manifestations and necessary auxiliary examinations. At the same time, it is necessary to determine whether there is an amniocentesis infection, and whether there is amniocentesis directly affects the subsequent treatment.

The clinical basis for the diagnosis of IAI:

(1) The maternal body temperature is >38 °C.

(2) The maternal white blood cell count is >15×109/L.

(3) maternal tachycardia (>100/min).

(4) Fetal tachycardia (>160/min).

(5) The tenderness of the uterus.

(6) Amniotic fluid has a stench.

Article 1 plus at least 2 of 2 to 6 can be diagnosed. For the diagnosis of IAI subclinical infection, amniocentesis for amniocentesis is the gold standard for IAI subclinical infection. Amniotic fluid culture time needs at least 24~48h. Therefore, some rapid detection methods can be used to assist in the diagnosis of IAI. For example, if 20 to 30 high power fields are examined, any number of bacteria and white blood cell counts per high power field are found to be >6; amniotic fluid blood glucose <0.83mmol/L; white blood cells>30×106/L; amniotic fluid IL-6>11ng/L, but The positive rate of amniotic fluid culture was lower in pregnant women with positive test results. The fetal heart rate variability may occur after PPROM, and fetal heart rate electronic monitoring can help to understand whether there is umbilical cord compression and symptomatic uterine contraction. Abnormal fetal heart monitoring is an indication of termination of pregnancy, however, at <32 weeks of gestation, because the fetus is not yet mature, even a healthy fetus may have an unresponsive type of fetal heart monitoring. However, once the fetal heart rate monitoring is reactive, the subsequent fetal heart rate non-responsive type suggests fetal distress. Ultrasound combined with clinical manifestations is instructive for expectant treatment. When the amniotic fluid volume is reduced (the amniotic fluid index <5cm or the maximum sheep pool depth <2cm, the labor incubation period may be shortened, and the incidence of NRDS is increased, but the maternal fetal infection rate does not increase. If the amniotic fluid continues to leak, it may cause too little amniotic fluid and too little amniotic fluid> 2 weeks can lead to fetal lung hypoplasia and fetal malformation, so once there is persistent oligohydramnios, the pregnancy should be terminated within 2 weeks. When the length of the cervix is 1~10mm and 30mm, the incidence of delivery within 7d is 83% and 18 respectively. %.

Note: typical premature rupture of membranes is easy to diagnose, but atypical premature rupture of membranes often causes serious consequences due to delay in diagnosis. The common clinical situation is that pregnant women consciously vaginal fluid, but the fluid stops after reaching the hospital. The inspector did not see the liquid outflow, and the litmus paper detected the vaginal fluid, pH <7.0, except that the premature rupture of the membrane was not treated or closely observed, so repeated, and finally until the amniocentesis occurred, the tire was recognized. Premature rupture of the membrane, the emphasis here is on the accuracy and importance of the vaginal discharge of normal pregnant women, while emphasizing the erroneousness of the various methods of examination, especially the litmus test method for detecting the pH of the vaginal opening rather than the intravaginal fluid. And the false negative of the result.

Differential diagnosis

Amniotic fluid must be differentiated from urine and vaginal mucus. It is easier to diagnose the premature rupture of membranes by vaginal examination and auxiliary diagnosis. However, there are still differences in the treatment of it, especially the treatment of premature rupture of membranes. The traditional concept holds that for those who are under-represented, expectant therapy should be taken to prolong the gestational age and improve the survival rate of newborns under the premise of close monitoring. However, some scholars believe that premature rupture of membranes is not enough, and the infection rate of mother and child far exceeds In the complications of premature infants, it is recommended to take anterior collateral amniotic fluid to determine phosphatidylglycerol. The maternal lung matures and terminates the pregnancy. It is also controversial whether antibiotics should be used in the treatment. Some scholars have suggested that preventive application of antibiotics can not reduce the perinatal morbidity. On the contrary, it can make resistant bacteria grow, so it is advocated that antibiotics are not used prophylactically. Most medical units in China are still difficult to diagnose subclinical infections in time. To prevent infection, it is still appropriate to use drugs. Penicillin or cephalosporin antibiotics are preferred, and those who are allergic to penicillin Macrolides can be used, and it is expected that during pregnancy, if symptoms of infection occur, the pregnancy should be terminated in time.

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