Postpartum hemorrhage is a bleeding from the birth canal which occurs in the early or late postpartum period. Postpartum hemorrhage is often a result of a major obstetric complication. The severity of postpartum hemorrhage is determined by the magnitude of blood loss. Bleeding is diagnosed after an examination of the birth canal, the uterine cavity, or an ultrasound. The treatment of postpartum hemorrhage requires an infusion-transfusion therapy, the introduction of uterotonic drugs, the closure of ruptures, and sometimes the extirpation of the uterus.
The danger of postpartum hemorrhage is that it can lead to a rapid loss of a large volume of blood and the death of the mother in childbirth. The presence of intensive uterine blood flow and the large wound surface after delivery contribute to the abundant blood loss. Normally the body of a pregnant woman is ready for physiologically tolerable blood loss in childbirth (up to 0.5% of body weight) due to an increase in the intravascular volume of blood. In addition, postpartum bleeding from the uterine wound is prevented by the increased contractions of the uterine muscles, compression and displacement into the deeper muscle layers of the uterine arteries with simultaneous activation of the coagulation system and thrombus formation in small vessels.
Early postpartum hemorrhage occurs within the first 2 hours after delivery, and later can develop between 2 hours and 6 weeks after the birth of the child. The outcome of postpartum hemorrhage depends on the volume of lost blood, the rate of bleeding, the effectiveness of conservative therapy, the development of DIC syndrome. The prevention of postpartum hemorrhage is an urgent task for obstetrics and gynecology.
Causes of postpartum hemorrhage
Postpartum hemorrhage often occurs due to a violation of the contractile function of the myometrium: hypotension (decreased tone and insufficient contractile activity of the uterine muscles) or atony (complete loss of the uterine tone, its ability to contract, lack of myometrium response to stimulation). The causes of such postpartum hemorrhages are fibroids and uterine myomas, cicatricial processes in myometrium, excessive stretching of the uterus in multiple pregnancy, polyhydramnios, prolonged labor by a large fetus, the use of drugs that reduce the tone of the uterus.
Postpartum hemorrhage may be caused by a delay in the uterine cavity of the remains of the placenta: placental lobules and parts of the membranes. This prevents the normal reduction of the uterus, provokes the development of inflammation and sudden postpartum hemorrhage. The partial increase in the placenta, the improper management of the third stage of labor, the discordant labor or a cervical spasm lead to a breakdown in the separation of the placenta.
The factors that cause postpartum hemorrhage may be endometrial hypotrophy or atrophy due to previously performed surgical interventions – cesarean section, abortions, conservative myomectomy, scraping of the uterus. The occurrence of postpartum hemorrhage may be caused by a violation of hemocoagulation in the mother, caused by congenital anomalies, the use of anticoagulants, the development of DIC syndrome.
Often postpartum hemorrhage develops with trauma (tearing) or dissection of the genital tract during childbirth. A high risk of postpartum hemorrhage occurs in the case of gestosis, premolars and premature detachment of the placenta, the threat of abortion, fetoplacental insufficiency, pelvic fetal presentation, the presence of endometritis or cervicitis in the mother, chronic cardiovascular and central nervous system, kidney or liver diseases.
Symptoms of postpartum hemorrhage
Clinical appearance of postpartum hemorrhage is caused by the volume and intensity of blood loss. With an atonic uterus that does not respond to external medical manipulations, postpartum bleeding is usually copious but can have a wave-like character which is sometimes relieved with the help of the medications that contract the uterus. The usual symptoms are arterial hypotension, tachycardia, and skin pallor.
The volume of hemorrhage up to 0.5% of the mass of the maternity body is regarded as physiologically acceptable; an increase in the volume of lost blood is considered pathological postpartum hemorrhage. The magnitude of blood loss exceeding 1% of body weight is considered massive, above it – critical. Critical hemorrhage can result in hemorrhagic shock and DIC syndrome with irreversible changes in vital organs.
In the late postpartum period, a woman should be concerned with intense and prolonged lochia, bright red discharge with large clots of blood, an unpleasant odor, and dragging pains in the lower abdomen.
Diagnosis of postpartum hemorrhage
Modern clinical gynecology assesses the risk of postpartum hemorrhage which includes monitoring hemoglobin level, the number of red blood cells and platelets in the blood serum, the time of bleeding and clotting, the state of the coagulating system of blood (coagulogram). Both hypotension and atony of the uterus can be diagnosed during the third labor stage due to flabbiness, weak contractions of the myometrium, a longer course of the post-natal period.
The diagnosis of postpartum hemorrhage is based on a thorough examination of the integrity of the excreted placenta and membranes as well as inspection of the birth canal for trauma. Under general anesthesia, the gynecologist carefully performs a manual examination of the uterine cavity for the presence or absence of ruptures, remaining parts of the afterbirth, blood clots, existing developmental malformations or tumors that prevent the contraction of the myometrium.
An important role in the prevention of late postpartum hemorrhage is played by an ultrasound of the pelvic organs on the 2-3 day after delivery, which allows detecting the remaining fragments of placental tissue and membranes in the uterine cavity.
Treatment of postpartum hemorrhage
In the case of postpartum hemorrhage, it is crucial to establish its cause, stop it immediately, prevent acute blood loss, restore the volume of circulating blood and stabilize the level of blood pressure. An integrated approach is important with the use of both conservative (medicamentous, mechanical) and surgical methods of treatment.
To stimulate the contractile activity of the muscles the uterus conducts catheterization and emptying of the bladder, local hypothermia (ice on the lower abdomen), gentle external massage of the uterus, and if there is no result, intravenous uterotonic drugs (usually metargergometrin with oxytocin), injections of prostaglandins into the cervix. To restore circulatory volume and eliminate the consequences of acute blood loss in postpartum hemorrhage, infusion-transfusion therapy is performed with blood components and plasma-substituting drugs.
The ruptures of the cervix, the walls of the vagina, and the perineum during the examination of the birth canal are sutured under local anesthesia. In the case of the abruption of the integrity of the placenta (even in the absence of bleeding) and hypotonic postpartum hemorrhage, an urgent manual examination of the uterine cavity under general anesthesia is performed. During the revision of the walls of the uterus manual separation of the remains of the placenta and membranes is carried out, blood clots are removed, the presence of ruptures of the uterus is examined.
In the case of uterus rupture an emergency laparotomy, wound suturing or removal of the uterus are performed. If there are signs of placenta increment as well as non-curable massive postpartum hemorrhage, subtotal hysterectomy (supravaginal amputation of the uterus) is indicated. If necessary, the procedure is accompanied by a ligation of the internal iliac arteries or embolization of the uterine vessels.
Operative interventions for postpartum hemorrhage are carried out simultaneously with resuscitation measures: compensation for hemorrhage, stabilization of hemodynamics and blood pressure. The performance of these procedures before the development of thrombohemorrhagic syndrome saves the woman in childbirth from the fatal outcome.
Prevention of postpartum hemorrhage
Women with unfavorable obstetric-gynecological history, disorders of the coagulation system, and also those who take in anticoagulants have a high risk of postpartum hemorrhage, therefore they are under special medical control during pregnancy and are sent to specialized maternity hospitals.
In order to prevent postpartum hemorrhage, women are injected with drugs that contribute to an adequate reduction in the uterus. The first 2 hours after childbirth, all such women spend in the maternity ward under the dynamic supervision of medical personnel to assess the volume of blood loss in the early postpartum period.