What Is a Postpartum Hemorrhage?

Postpartum hemorrhage of more than 500mL within 24 hours after delivery is called postpartum hemorrhage, and 80% occurs within 2 hours after delivery. Late postpartum hemorrhage refers to a large amount of uterine bleeding that occurs during the puerperium after 24 hours of delivery. Postpartum hemorrhage is a serious complication during childbirth and is one of the four major causes of maternal death. Bleeding in China has been the number one cause of maternal death in recent years, especially in remote and backward areas. The incidence of postpartum hemorrhage accounts for 2% to 3% of the total number of births. The actual incidence is higher due to the larger subjective factors in measuring and collecting the amount of bleeding.

Basic Information

English name: postpartum hemorrhage
Visiting department: Obstetrics and Gynecology
Common causes: Contraction weakness, placental factors, soft birth canal laceration, coagulopathy, uterine inversion

Common symptoms: Vaginal bleeding, hemorrhagic shock, secondary anemia
Contagious: no

Causes of postpartum hemorrhage

The causes of postpartum hemorrhage are as follows: weak uterine contraction, soft birth canal laceration, placental factors, and coagulopathy. The four major causes can be combined, or they can be mutually causal.

Weak contraction

It is the most common cause of postpartum hemorrhage, accounting for 70%. The anatomical distribution of uterine muscle fibers is interlaced with inner ring, outer longitudinal, and middle. Under normal circumstances, after the fetus is delivered, the contraction of uterine muscle fibers traveling in different directions exerts an effective compression effect on the blood vessels between the muscle bundles. If uterine muscle fiber contraction is weak, that is, uterine contraction is weak, it will lose the effective compression effect on blood vessels and cause postpartum hemorrhage. Common factors are: systemic factors: women are extremely nervous due to excessive fear of childbirth, especially lack of sufficient confidence in vaginal delivery can cause contractions uncoordinated or contraction weakness. In this case, sedatives and anesthetics may be required after labor, which will increase postpartum uterine fatigue and cause postpartum hemorrhage; Obstetric factors: excessive labor may cause maternal extreme fatigue and systemic failure, or excessive labor may cause uterine contractions Weakness; too much amniotic fluid, huge children and multiple pregnancies make the uterine muscle fibers excessively stretched, and the postpartum muscle fiber contraction ability is poor. The uterine muscle fibers are damaged due to multiple deliveries, which can cause uterine contraction weakness. Obstetric complications such as preeclampsia (severe), severe anemia, uterine cavity infection, and comorbidities cause uterine muscle fiber edema and cause uterine contraction weakness; uterine factors: uterine muscle fiber dysplasia, such as uterine malformations or uterine fibroids.

2. Placental factor

About 20% of the causes of postpartum hemorrhage. According to the placenta peeling, placental retention, placental adhesion, and some placental and / or placental membrane residues can all affect uterine contractions and cause postpartum hemorrhage. Placental retention: Placenta is retained if the placenta has not been discharged within 30 minutes after the fetus is delivered. May be used improperly with uterine contraction agents or rough massage of the uterus, which stimulates spasmodic contractions, forms a contraction ring at the uterus, the junction of the lower segment, or the outer cervix, and causes the placenta to be embedded in the uterine cavity and causes placental retention; Weakness or compression of the lower uterus due to bladder filling can also cause the placenta to remain in the uterine cavity, although it has been stripped. If placental retention prevents normal contractions, it will cause postpartum hemorrhage, and blood clots will accumulate in the uterine cavity, which will cause the uterine cavity to enlarge and cause contraction fatigue. If not treated in time, a vicious circle will be formed and serious consequences will occur. The main reasons for placental adhesions Related to improper operation. If the uterus is massaged prematurely or excessively after delivery, it interferes with the normal contraction and contraction of the uterus, causing partial separation of the placenta, open blood sinus opening on the dissected surface, and excessive bleeding. It can also be caused by multiple previous curettage or intrauterine cavity operations. Endometrial damage can easily cause placental adhesion or implantation.

3. Soft birth canal laceration

Soft birth canal lacerations include lacerations of the perineum, vagina, and cervix and lower uterus. Common factors: poor elasticity of the vulva tissue, changes in inflammation of the vulva, and vagina; sudden delivery, excessive fertility, and large children; vaginal surgery for midwifery; careless examination of the soft birth canal, and missing bleeding points. Incomplete suture and hemostasis.

4. Coagulation dysfunction

Common causes include placental abruption, amniotic fluid embolism, stillbirth, and acute fatty liver disease during pregnancy. A few are caused by primary blood diseases such as thrombocytopenia, leukemia, aplastic anemia, or severe viral hepatitis.

5. Inverted uterus

Rarely, it is mostly caused by improper handling of the third stage of labor, such as pressing the palace floor strongly or pulling the umbilical cord. [1]

Clinical manifestations of postpartum hemorrhage

Postpartum hemorrhage mostly occurs within 2 hours after the fetus is delivered, and can occur before, after, or before and after the placenta is delivered. Vaginal bleeding can be a major short-term bleeding, or a small amount of continuous bleeding for a long time. Generally it is dominant, but there are also hidden bleeding.

The clinical manifestations are mainly vaginal bleeding, hemorrhagic shock, and secondary anemia. If there is too much blood loss, it may be accompanied by diffuse intravascular coagulation. Symptoms vary depending on the amount and speed of blood loss and whether or not they have anemia. In the short term, major bleeding can quickly occur. It should be noted that in the early stage of shock, the vital signs of patients such as pulse and blood pressure may be within the normal range due to the compensatory mechanism in the body. However, at this time, close monitoring is still needed to identify the risk factors early, evaluate the amount of bleeding and actively treat it. In clinical practice, there are often decompensated manifestations such as a rapid pulse rate and a decrease in blood pressure that cause attention when blood loss occurs to a certain extent, thus losing the best opportunity for treatment. In addition, if the maternal is already suffering from anemia, even if there is not much bleeding, shock can occur and it is not easy to correct. Therefore, every mother must be thoroughly observed and analyzed to avoid delaying the rescue time.

Diagnosis of postpartum hemorrhage

The key to diagnosing postpartum hemorrhage lies in the correct measurement and estimation of blood loss. The methods commonly used in clinical practice to estimate blood loss are: volume method; weighing method; area method; shock index and so on. Inaccurate bleeding measurement will lose the best time to rescue postpartum hemorrhage. Suddenly large amounts of postpartum hemorrhage are easy to pay attention to and early diagnosis, and slow and continuous small amount of bleeding (such as soft suture of soft birth canal suture) and undetected hematoma are often important reasons for delayed diagnosis and treatment.

According to the relationship between the time and quantity of vaginal bleeding and the birth of the fetus and placenta, the cause of postpartum hemorrhage can be initially determined. Several causes often cause each other.

Postpartum hemorrhage treatment

The principle of managing postpartum hemorrhage is to target the cause, quickly stop bleeding, replenish blood volume, correct shock and prevent infection.

Hemostasis

Uterine contraction and fatigue bleeding, strengthening the contraction is the fastest and most effective method of hemostasis.

(1) Remove the causes of uterine contraction fatigue, improve the general condition, and urethral catheterization can relieve overfilling of the bladder.

(2) Massage the uterus Abdominal massage of the uterus is the simplest and most effective way to promote uterine contraction to reduce bleeding. After the bleeding stops, you must massage intermittently and evenly to prevent the uterus from relaxing again. If necessary, you need to massage the uterus with both hands. You can place one hand on the anterior vaginal fornix, against the anterior wall of the uterus, and press the other hand against the posterior wall of the uterus while performing massage. Massage techniques should be carried out gently and rhythmically. Do not continue to apply excessive force for a long time to damage the uterine muscles and cause ineffectiveness.

(3) uterine contraction agent oxytocin is a first-line drug to prevent and treat postpartum hemorrhage. The rate of administration should be adjusted according to the uterine contraction and bleeding of the patient. Intravenous infusion works immediately, but the half-life is short, so continuous intravenous infusion is needed. If the oxytocin receptor does not function after supersaturation, the total amount should be controlled at 60U within 24 hours. Carprost tromethamine is a prostaglandin F2 derivative (15-methyl PGF2), which causes a coordinated and powerful contraction throughout the uterus. Patients with asthma, heart disease and glaucoma are contraindicated, and those with hypertension should be used with caution. Common side effects are nausea, vomiting, and diarrhea. Misoprostol is a derivative of prostaglandin PGE1, which causes strong contraction of the entire uterus, but the side effects of misoprostol are large, and nausea, vomiting, diarrhea, chills and elevated body temperature are more common; hypertension, active heart, liver, and kidney disease And adrenal insufficiency should be used with caution, glaucoma, asthma and allergies are contraindicated.

(4) Intrauterine tamponade When the above treatments are not effective, in order to retain the uterus or reduce preoperative blood loss, it is feasible to use intrauterine tampon gauze to stop bleeding. Pay attention to filling the uterine cavity from the bottom of the palace and both sides of the palace. The fortress should be filled tightly without leaving any gaps to achieve the purpose of compressing and stopping bleeding. If the bleeding stops, the sliver can be removed after 24 to 48 hours. Antibiotics are needed to prevent infection after tamponade, and uterine contractions should be injected before removal.

(5) B-Lynch suture is suitable for patients with uterine contraction weakness, placental factors and abnormal coagulation function postpartum hemorrhage, manual massage and uterine contraction agents are ineffective and may remove the uterus. First try to use two-hand compression to observe whether the amount of bleeding is reduced to estimate the possibility of successful hemostasis by B-Lynch suture. Absorbable suture should be applied. Reports of postoperative complications of B-Lynch are rare, but infection and tissue necrosis are possible, and surgical indications should be mastered.

(6) Ligature of the superior and inferior branches of the uterine artery and the internal iliac artery 90% of uterine blood flow through the uterine artery during pregnancy. The above measures can preserve the uterus and preserve fertility.

(7) Compression of the abdominal aorta When the bleeding does not stop, the abdominal aorta can be compressed through the abdominal wall toward the spine, or it can be compressed through the posterior wall of the uterus. When the uterine muscles are hypoxic, they can induce contractions and reduce bleeding. Obtain temporary results and gain time for other measures.

(8) Transcatheter arterial embolization (TAE) percutaneously intubates from the femoral artery under local anesthesia to show the internal iliac artery, and then injects an embolic agent that can be absorbed to embolize the internal iliac artery to achieve hemostasis. The time it takes to operate is related to the proficiency of the operator.

(9) Hysterectomy is the most effective way to control obstetric bleeding. Various hemostatic measures have no obvious effect and bleeding cannot be controlled. To save lives, at the same time of transfusion and anti-shock, subtotal or total hysterectomy is performed.

2. Bleeding due to soft birth canal injury

With the soft birth canal fully exposed, identify the site of the laceration and note the presence of multiple lacerations. When suturing, try to restore the original anatomical relationship, and the suture should be 0.5cm above the top of the tear. A laceration of more than 1 cm should be sutured even if there is no active bleeding. The hematoma should be cut open to remove the accumulated blood, stitched to stop hemostasis, or packed with iodine spinning strips to stop the hemostasis, and removed after 24 to 48 hours. Small hematomas can be closely observed, and conservative treatment such as cold compresses and compressions can be used.

If the uterine inversion is found in time, the maternal has no severe shock or bleeding, and the cervical ring has not yet tightened. The uterine body can be immediately accepted (if necessary, after anesthesia), and the intravenous oxytocin can be added after the inversion. Withdraw until the contraction is good. Because the maternal pain is severe and there are many shock manifestations, it is often necessary to reset under clinical anesthesia and vital signs monitoring. If the vaginal delivery fails, it can be replaced by abdominal uterine delivery. If the patient's blood pressure is unstable, the anti-shock is performed at the same time.

For complete uterine rupture or incomplete uterine rupture, open immediately for surgical repair or hysterectomy.

3. Placental-induced bleeding

(1) Hemorrhage due to placenta retention or placental membrane residual fetus more than 30 minutes after delivery, although the placenta has not been stripped through general treatment, or with major bleeding, the placenta should be stripped by hand as soon as possible. After the placenta is delivered naturally or manually, the placental membrane is checked for residues, which can be removed by gently scraping with a large spatula. If the placenta has been completely detached but incarcerated in the uterine cavity, the cervix is tight and contracted, and it can be removed by hand under anesthesia.

(2) Placental implantation or placental penetration For those who have been identified for placental implantation, do not force clamp or curettage to avoid fatal postpartum hemorrhage. According to the size of the placenta implantation area and the conditions of the hospital, you can choose hemostasis with gauze packing, hemostasis with sac compression, ligation or embolization of uterine artery or internal iliac artery to stop bleeding. If there is too much bleeding and the hemostasis through the above method is invalid, it will save the life of the mother Subtotal or total hysterectomy should be selected in time.

4. Bleeding due to coagulopathy

The diagnosis should be made on the basis of actively treating the primary disease, and the corresponding coagulation factors should be quickly added. Platelets: used when platelets are lower than (20-50) × 10 ⁹ / L or when platelets are reduced and uncontrollable bleeding occurs; fresh frozen plasma: fresh anticoagulated whole blood. Plasma is separated within 6-8 hours and quickly frozen, almost stored All blood coagulation factors, plasma proteins, and fibrinogen are described. Cryoprecipitation: Cryoprecipitation infusion is mainly to correct the lack of fibrinogen. For example, if the fibrinogen concentration is higher than 150mg / dL, cryoprecipitation is not necessary. Fibrinogen: Entering 1g of fibrinogen can raise fibrinogen in blood by 25g / L; thrombinogen complex.

5. Prevention and treatment of shock

(1) When postpartum hemorrhage occurs, fluid should be transfused and transfused as appropriate while hemostasis, pay attention to heat preservation, and give appropriate sedatives to prevent shock. After the occurrence of shock, rescue by hemorrhagic shock. The main cause of death from hypovolemic shock due to blood loss is multiple organ dysfunction syndrome (MODS) caused by tissue hypoperfusion and major bleeding, infection, and reperfusion injury. Therefore, the key to treatment is to remove the cause of shock as soon as possible, and to restore effective tissue perfusion as soon as possible to improve the oxygen supply of tissue cells, restore the balance of oxygen supply and demand, and restore normal cell function.

(2) Early diagnosis of hypovolemic shock is important for prognosis. Traditional diagnosis is based on medical history, symptoms, and signs, including changes in mental state, skin coldness, decreased systolic blood pressure (40mmHg), or decreased pulse pressure difference (100 / min, central venous pressure (CVP) <5mmHg, or pulmonary artery wedge pressure (PAWP) ) <8mmHg and other indicators. Studies have confirmed that blood lactic acid and alkali deficiency are of great significance in monitoring and prognosis of hypovolemic shock.

(3) Effective monitoring can make a correct and timely assessment and judgment of the condition and treatment response of patients with hypovolemic shock, so as to help guide and adjust the treatment plan and improve the prognosis of patients with shock. General clinical monitoring includes monitoring indicators such as skin temperature and color, heart rate, blood pressure, urine output, and mental state. Increased heart rate is often one of the early diagnostic indicators of shock. It is appropriate to maintain a blood pressure of at least a mean arterial pressure (MAP) of 60 to 80 mmHg. Urine volume is a good indicator of renal perfusion and can indirectly reflect circulation. When urine volume is <0.5mL / (kg · h), fluid resuscitation should be continued. Body temperature monitoring is also very important. When the central body temperature is <34 ° C, it can cause severe coagulation dysfunction. It is emphasized that when the postpartum hemorrhage is about 1000mL, the vital signs of the maternal may still be within the normal range due to the body's compensation mechanism. It should not be ignored to observe the early shock performance of the maternal and treat it in a timely manner. At the same time, laboratory monitoring should be strengthened.

(4) Effective venous access must be established quickly during emergency volume resuscitation. Liquid resuscitation treatment can choose crystal solution and colloidal solution. Because the 5% glucose solution quickly distributes into the intercellular space, it is not recommended for fluid resuscitation treatment.

Under normal circumstances, intra- and extra-vascular redistribution will occur after infusion of crystal fluid, and about 25% will remain in the blood vessels; the remaining 75% will be distributed in the extravascular space to supplement the fluid loss in the interstitial space while maintaining the acid and alkali in the interstitial space. Balanced, but excess can also cause tissue edema. The colloid fluids used in the clinical treatment of hypovolemic shock resuscitation mainly include hydroxyethyl starch and albumin. In terms of safety, attention should be paid to the effects on renal function, the effects on blood coagulation, and possible allergic reactions, and there is a certain dose correlation. Albumin is expensive and has the potential to spread blood-borne diseases with less clinical application.

6. Blood transfusion treatment

Blood transfusion and blood transfusion products are widely used in hypovolemic shock. During postpartum hemorrhage and hemorrhagic shock, the body undergoes self-transfusion (that is, redistribution of blood to ensure the supply of vital organs and the brain) and pathophysiological changes of the infusion to achieve the body's compensatory effect. In particular, when the body is in the decompensation stage, in principle, crystals should be quickly input to ensure the loss of fluid in the interstitial space and the acid-base balance of the microenvironment in the interstitial space, and then the most important thing is to increase the hemoglobin concentration to ensure that the tissue cells can perform normal Oxygen metabolism. Because the uterine muscle fibers are in a state of severe ischemia and hypoxia, they are not sensitive to uterine contractions and various hemostatic methods. It is also important to supplement coagulation factors based on the above to correct coagulation abnormalities. It is emphasized that the postpartum hemorrhage fluid resuscitation must be based on the pathophysiology of the body after the occurrence of postpartum hemorrhage. According to the postpartum hemorrhage volume and the monitoring of vital signs, an individualized liquid resuscitation treatment plan is selected on the basis of standardized fluid resuscitation treatment. At the same time, attention should be paid to correct acidosis in time, protect the gastrointestinal mucosal barrier function, and maintain body temperature is the key to resuscitation. Therefore, warm blood transfusion should be adopted to improve the success rate of resuscitation.

7. Prevention of infection

Because of blood loss, decreased body resistance, combined with transvaginal uterine cavity operation, etc., women are prone to infection of the production mattress, and should be actively prevented. [2]

Prevention of postpartum hemorrhage

1. Strengthen prenatal inspection

In cases of postpartum hemorrhage, delayed labor, dystocia, and anemia, prenatal hemorrhage, pregnancy-induced hypertension, large fetuses, twins or polyhydramnios, etc., preparations for postpartum hemorrhage should be actively prepared. Actively correct anemia, treat basic diseases, and fully understand the high-risk factors of postpartum hemorrhage. High-risk pregnant women should be referred to hospitals with blood transfusion and rescue conditions before delivery.

2.Identify high risk factors for postpartum hemorrhage during labor

Identify the high-risk factors of postpartum hemorrhage during the labor process and intervene in time. Avoid prolonged labor, pay attention to the feeding and rest of the mother, pregnant women with a longer labor should ensure sufficient energy intake, empty the bladder in time, and appropriately apply sedatives, infusions and urine catheterization if necessary. In the second stage of labor, pay attention to controlling the birth rate of the fetal head to avoid laceration and bleeding in the birth canal. Avoid rough operation during midwifery to avoid damaging the soft birth canal. For pregnant women who are too long, have an acute or active period, and have a quicker second stage, they should be alert to postpartum hemorrhage. And in the morning to prepare for delivery, apply a contraction agent at the appropriate time, massage the uterus properly, and accurately measure the amount of bleeding.

3. Actively handle the third stage of labor

Active intervention during the third stage of labor can effectively reduce postpartum hemorrhage. The main interventions include the prophylactic use of oxytocin after the delivery of the fetal head and immediately before the delivery of the shoulder. Non-head fetuses can be used for prophylactic oxytocin after the fetus has been delivered systemically and after the last fetus of a multiple pregnancy; the fetus is controlled to pull the umbilical cord to assist the placenta delivery; after the placenta is delivered, massage the uterus. In addition, after the placenta is delivered, the placenta and fetal membranes should be carefully checked for integrity, and there are no placenta and birth canal injuries. If problems are found, they should be dealt with in time.

4. Other

2 hours postpartum is a high-risk period for postpartum hemorrhage. Closely observe the uterine contraction and bleeding volume, and the bladder should be emptied in time. Within 24 hours after giving birth, the mother should be instructed to pay attention to bleeding. Patients who have an increasing trend of postpartum bleeding should carefully measure the amount of bleeding to avoid underestimation of blood loss. [3]

References:

1. Obstetrics Group, Obstetrics and Gynecology Branch, Chinese Medical Association. Guidelines for the prevention and management of postpartum hemorrhage (draft): Chinese Journal of Obstetrics and Gynecology, 2009: 44 (7).

2. Chinese Medical Association Critical Medicine Branch. Guidelines for Low Blood Volume Resuscitation: Chinese Journal of Practical Surgery, 2007: 27 (8).

3. Wei Wei, Zhao Yangyu and others. Clinical analysis of hysterectomy and uterine arterial embolization for refractory obstetric hemorrhage: Chinese Journal of Obstetrics and Gynecology, 2008: 9 (6).