Continuing Education Activity

Obstetric hemorrhage is the most common and dangerous complication of childbirth. Traditionally, postpartum hemorrhage (PPH) has been defined as greater than 500 mL estimated blood loss associated with vaginal delivery or greater than 1000 mL estimated blood loss associated with cesarean delivery. This was redefined by the American College of Obstetrics and Gynecology in 2017, and the current definition is cumulative blood loss greater than 1000 mL with signs and symptoms of hypovolemia within 24 hours of the birth process, regardless of the route of delivery. While this change was made with the knowledge that blood loss at the time of delivery is routinely underestimated, blood loss at the time of vaginal delivery greater than 500 mL should be considered abnormal with the potential need for intervention. Primary postpartum hemorrhage is bleeding that occurs in the first 24 hours after delivery, while secondary postpartum hemorrhage is characterized as bleeding that occurs 24 hours to 12 weeks postpartum. This activity reviews the causes of postpartum hemorrhage and highlights the role of the interprofessional team in the management of these patients.

Objectives:

• Identify the etiology of postpartum hemorrhage.
• Describe the presentation of a patient with postpartum hemorrhage.
• Outline the management options available for postpartum hemorrhage.
• Review interprofessional team strategies for improving care coordination and communication to advance the treatment of postpartum hemorrhage and improve outcomes.

Introduction

Obstetric hemorrhage is the most common and dangerous complication of childbirth. Traditionally, postpartum hemorrhage (PPH) has been defined as greater than 500 mL estimated blood loss in a vaginal delivery or greater than 1000 mL estimated blood loss at the time of cesarean delivery. This was redefined in 2017 by the American College of Obstetrics and Gynecology as a cumulative blood loss greater than 1000 mL with signs and symptoms of hypovolemia within 24 hours of the birth process, regardless of the route of delivery. While this change was made with the knowledge that blood loss at the time of delivery is routinely underestimated, blood loss at the time of vaginal delivery greater than 500 mL should be considered abnormal with the potential need for intervention. Primary postpartum hemorrhage is bleeding that occurs in the first 24 hours after delivery, while secondary postpartum hemorrhage is characterized as bleeding that occurs 24 hours to 12 weeks postpartum.[1][2][3]

Etiology

Acute postpartum hemorrhage has several potential causes and can be mainly divided into primary and secondary. Primary causes of postpartum hemorrhage include:

• Uterine atony
• Genital tract lacerations
• Retained placenta
• Uterine inversion
• Abnormal placentation
• Coagulation disorders

Uterine atony, or lack of effective contraction of the uterus, is the most common cause of postpartum hemorrhage. Postpartum hemorrhage in a previous pregnancy is a significant risk factor and providers should make all the effort to establish its severity and cause.

Secondary causes of postpartum hemorrhage include:[4][5][6][7]

• Retained products of conception
• Infection
• Subinvolution of the placental site
• Inherited coagulation deficits

Epidemiology

Postpartum hemorrhage is the leading cause of morbidity and mortality in childbirth. PPH occurs in approximately 1% to 6% of all deliveries. Uterine atony, the primary cause of PPH, accounts for 70% to 80% of all hemorrhage.[8]

Pathophysiology

Risk factors for postpartum hemorrhage (PPH) are dependent on the etiology of the hemorrhage. Risk factors for uterine atony include high maternal parity, chorioamnionitis, prolonged use of oxytocin, general anesthesia, and conditions that cause increased distention of the uterus such as multiple gestation, polyhydramnios, fetal macrosomia, and uterine fibroids. Risk factors that can lead to uterine inversion include excessive umbilical cord traction, short umbilical cord, and fundal implantation of the placenta. Genital tract trauma risk factors include operative vaginal delivery and precipitous delivery. Retained placenta and abnormal placentation are more common if an incomplete placenta is noted at delivery, a succenturiate lobe of the placenta is present, or if the patient has a history of previous uterine surgery. Coagulation abnormalities are more common in patients presenting with fetal death in utero, placental abruption, sepsis, disseminated intravascular coagulopathy (DIC), and in those with a history of an inherited coagulation defect.

The California PPH toolkit states that those patients who are bleeding on presentation to labor and delivery, those with a history of PPH, hematocrit less than 30%, history of bleeding diathesis or coagulation deficit, morbidly adherent placenta, or with hypotension or tachycardia on presentation to labor and delivery should be considered high risk for PPH on admission.[9][10][11][12]

History and Physical

Patients present with acute bleeding post-partum from the vagina. The patient may also have an increased heart rate, an increased respiratory rate, and feeling faint while standing up. As the patient continues to lose blood, they may also feel cold, have decreased blood pressure, and may lose consciousness. Patients may also have signs and symptoms of shock, such as confusion, blurry vision, clammy skin, and weakness.

Evaluation

Initial evaluation of the patient should include a rapid assessment of the patient’s status and risk factors. In postpartum women, signs or symptoms of blood loss such as tachycardia and hypotension may be masked, so if these signs are present, there should be a concern for considerable blood volume loss (greater than 25% of total blood volume). Continuous assessment of vital signs and ongoing estimation of total blood loss is an important factor in ensuring safe care of the patient with PPH.

An exam of the patient at the time of hemorrhage can help to identify the probable cause of bleeding focused on any specific risk factors the patient may have. A rapid assessment of the entire genital tract for lacerations, hematomas, or signs of uterine rupture should be performed. A possible manual exam and extraction for any retained placental tissue or assessment by bedside ultrasound may be a part of the evaluation. A soft, “boggy” or non-contracted uterus is the common finding with uterine atony. Uterine inversion presents as a round bulge or mass with palpation of the fundal wall in the cervix or lower uterine segment and is often associated with excessive traction on the umbilical cord or abnormally adherent placenta. Widespread bleeding, such as from venipuncture sites, is a sign of disseminated intravascular coagulation (DIC).

Laboratory studies can be ordered in a PPH to help evaluate and manage the patient, although interventions such as medication or blood product administration should not be withheld, pending the results of such studies. Type and screen or crossmatch may be ordered to prepare for possible blood transfusion. Complete blood count to assess hemoglobin, hematocrit, and platelets can be evaluated at intervals, although lab values often lag behind the clinical presentation. Coagulation studies and fibrinogen will be useful in the patient where DIC is suspected.

Treatment / Management

The treatment and management of postpartum hemorrhage are focused on resuscitation of the patient while identifying and treating the specific cause.[13]

Maintaining the hemodynamic stability of the patient is important to ensure continued perfusion to vital organs. Ample intravenous (IV) access should be obtained. Careful direct assessment of cumulative blood loss is important, and a focus should be on the early initiation of protocols for the release of blood products and massive transfusion protocols.

Rapid identification of the cause of postpartum hemorrhage and the initiation of treatment should be made simultaneously. Transfer to an operating suite with anesthesia assistance may be indicated for help with a difficult laceration repair, to correct uterine inversion, to help provide analgesia if needed for removal of retained products, or if surgical exploration is indicated.

If the postpartum hemorrhage is due to uterine atony, treatment modalities include medical management with uterotonic agents, uterine tamponade, pelvic artery embolization, and surgical management.

Medical management with uterotonic and pharmacologic agents is typically the first step if uterine atony is identified. While oxytocin is given routinely by most institutions at the time of delivery (see prevention), additional uterotonic medications may be given with bimanual massage in an initial response to hemorrhage. Uterotonic agents include oxytocin, ergot alkaloids, and prostaglandins. Commonly used uterotonics include:

• Oxytocin: A hormone naturally produced by the posterior pituitary works rapidly to cause uterine contraction with no contraindications and minimal side effects.

• Methylergonovine: Semi-synthetic ergot alkaloid. It works rapidly for sustained uterine contraction. It is contraindicated in patients with hypertension.

• Carboprost: Synthetic prostaglandin analog of PGF contraindicated in severe hepatic, renal, and cardiovascular disease, may cause bronchospasm in patients with asthma.

• Misoprostol: Prostaglandin E1 analog. More delayed onset than the above medications.

If bimanual massage and uterotonic medications are not sufficient to control hemorrhage, uterine tamponade may be considered. An intrauterine balloon tamponade system can be used, typically by filling an intrauterine balloon with 250 to 500 mL of normal saline. If there is not an intrauterine balloon readily available, the uterus may be packed with gauze, or multiple large Foley catheters may be placed concurrently. It is important to keep an accurate count of anything placed in the uterus to prevent retained foreign bodies.

Uterine artery embolization may be considered in a stable patient with persistent bleeding. Fluoroscopy is used to identify and occlude bleeding vessels. While the unstable patient is not a candidate for this modality, it has the benefit of uterine conservation and possible future fertility.

Exploratory laparotomy is typically indicated in the setting where less invasive measures for postpartum hemorrhage have failed or if the suspected reason for postpartum hemorrhage such as morbidly adherent placenta, demands it. A midline vertical abdominal incision should be considered to maximize exposure; however, if the patient had a cesarean delivery, the existing incision may be utilized. Vascular ligation sutures may be attempted to decrease pulse pressure at the uterus. Bilateral uterine artery ligation (O’Leary sutures) sutures may be placed as well as bilateral utero-ovarian ligament ligation sutures. Ligation of the internal iliac arteries may also be performed; however, as this entails a retroperitoneal approach, it is rarely used. Uterine compression sutures may also be used as a treatment for atony. The B-Lynch suture technique, the most commonly performed among the compression sutures, physically compresses the uterus looping from the cervix to the fundus. The definitive treatment for postpartum hemorrhage is a hysterectomy. A peripartum hysterectomy is associated not only with permanent sterility but also increased surgical risk with a higher risk of bladder and ureteral injury. Supracervical hysterectomy may be performed alternately as a faster surgery with potentially fewer complicated risks.

If the PPH has a cause other than atony, the treatment modality should be specifically tailored to the cause. Genital tract lacerations should be repaired or pressure/packing used. Retained products of conception should be removed manually or by dilation and curettage procedure. Hematomas can be managed by observation alone or may need fluoroscopy/embolization or surgical intervention if needed. If the uterine inversion is the cause of PPH, steady pressure with the fist is used to replace the uterus in the correct position. Uterine relaxants such as a halogenated anesthetic, terbutaline, magnesium sulfate, or nitroglycerine can be used during uterine repositioning, with oxytocin and other uterotonics given once the uterus is in normal anatomical position. Occasionally surgical correction of inversion must be undertaken via laparotomy. If a coagulation deficit exists, blood factor and product replacement may be used to correct the deficit.

Differential Diagnosis

The differential diagnosis for the causes of early PPH include:

• Uterine atony
• Lacerations
• Uterine inversion
• Retained placenta
• Uterine rupture

Prognosis

Postpartum hemorrhage is a leading cause of maternal and fetal morbidity in the United States. Correct and timely institution of treatment can vastly improve patient outcomes.

In addition, the females who have had a PPH in one delivery are at risk of having PPH in subsequent deliveries. The use of intramuscular or intravenous oxytocin correctly has improved patient outcomes.

Complications

As the loss of blood occurs in postpartum hemorrhage, the patient is at risk of hypovolemic shock. When the patient loses 20% of the blood, they develop tachycardia, tachypnea, narrowed pulse pressure, and delayed capillary refill. This may lead to ischemic injury to the liver, brain, heart, and kidney.

Sheehan syndrome or postpartum hypopituitarism is one of the complications of excessive blood loss seen in postpartum hemorrhage.

The complications related to management include the following:

• Transfusion-related acute lung injury
• Infections
• Hemolytic transfusion reactions

Consultations

An interprofessional approach is mandatory for the required outcomes in the management of a patient suffering from acute postpartum hemorrhage. There are some crucial consultations that are usually required in managing such patients:

• Obstetrics and gynecology
• General surgery
• Anesthetist
• Hematologist
• Labor and delivery nurses
• Laboratory personnel
• Interventional radiology

Deterrence and Patient Education

Preventative techniques can be used in patients to prevent atony and PPH, including active management of the third stage of labor with oxytocin administration, uterine massage, and umbilical cord traction. Identifying high-risk patients before delivery is one of the most important factors in preventing morbidity and mortality associated with PPH. This allows for planning appropriate routes and timing of delivery in the appropriate medical resource setting. Patients with previous cesarean delivery should have ultrasound evaluation antepartum to help determine the appropriate route and place of delivery. Treatment of patients with anemia by either oral or parenteral iron supplementation should be considered, especially in patients with hematocrit less than 30%. Additionally, consideration for erythropoietin stimulating agents with hematology consultation should be undertaken in high-risk patients, especially in those who do not accept a blood transfusion.

Standardized, multidisciplinary protocols have been used to help decrease severe maternal morbidity associated with postpartum hemorrhage that involves a focus on unit readiness, recognition and prevention, response, and reporting/systems learning. The nursing and anesthesia teams should be aware of the postpartum hemorrhage and be available to assist. Simulation activities can be utilized in event training in PPH and have been shown to improve outcomes.

Enhancing Healthcare Team Outcomes

Postpartum hemorrhage is one of the surgical emergencies in obstetrics. The condition is best managed by an interprofessional team that also includes laboratory personnel and labor and delivery nurses.

The treatment and management of postpartum hemorrhage are focused on resuscitation of the patient while identifying and treating the specific cause. However, in many cases, the cause is surgical. Maintaining the hemodynamic stability of the patient is important to ensure continued perfusion to vital organs. Ample intravenous (IV) access should be obtained. Careful direct assessment of cumulative blood loss is important, and a focus should be on the early initiation of protocols for the release of blood products and massive transfusion protocols. Rapid identification of the cause of postpartum hemorrhage and initiating treatment should be made simultaneously. To improve outcomes, the resuscitation should be done in an operating department setting as anesthesia assistance may be indicated for help with a difficult laceration repair, to correct uterine inversion, to help provide analgesia if needed for removal of retained products, or if surgical exploration is indicated.