Postpartum haemorrhage is excessive bleeding that occurs after childbirth, affecting between 1 and 5 out of every 100 women who give birth. Though it’s a serious medical emergency that can be life-threatening, early recognition and quick treatment usually lead to full recovery.

Epidemiology

Postpartum haemorrhage occurs in approximately 1 to 5 percent of all deliveries worldwide, making it one of the most common complications following childbirth. Despite being relatively common, most cases are not life-threatening when treated promptly. The condition affects women globally, though its impact varies significantly across different regions and healthcare settings.^[1][7]

The global burden of postpartum haemorrhage is substantial. Worldwide, an estimated 14 million women experience this condition each year, resulting in around 70,000 deaths. This tragic statistic means that approximately one woman dies every six minutes from bleeding after childbirth. Most of these deaths occur in low and middle-income countries where access to immediate medical care and blood products may be limited.^[17]

In the United States, postpartum haemorrhage is responsible for slightly more than 10 percent of maternal deaths, translating to approximately 1.7 deaths per 100,000 live births. It’s worth noting that the rate of postpartum haemorrhage in the United States increased by 26 percent between 1994 and 2006, primarily due to increased rates of uterine atony (when the uterus fails to contract properly after birth). However, maternal mortality from postpartum haemorrhage has decreased since the late 1980s, likely due to improved recognition and treatment strategies including more frequent use of blood transfusions.^[3]

Haemorrhage that requires blood transfusion is the leading cause of severe maternal morbidity in the United States. The condition doesn’t discriminate based on race or age, though certain demographic groups may face higher risks due to underlying health conditions or access to care issues.^[3]

Causes

Understanding why postpartum haemorrhage happens requires knowing what normally occurs after birth. During pregnancy, the placenta (the organ that provides oxygen and nutrients to the baby) attaches to the wall of the uterus. After the baby is born, the uterus continues to contract, which helps deliver the placenta and compress the blood vessels where the placenta was attached. When this process doesn’t work as it should, excessive bleeding can occur.^[1]

Healthcare professionals often remember the causes of postpartum haemorrhage using a helpful memory tool called the “Four T’s.” This refers to tone, tissue, trauma, and thrombin, which represent the four main categories of causes.^[5]

The most common cause, accounting for up to 80 percent of cases, is problems with tone. This means the uterus doesn’t contract strongly enough after delivery. When the muscle fibers of the uterus fail to tighten and compress the blood vessels at the site where the placenta was attached, these vessels continue to bleed freely. This condition is called uterine atony.^[1][4]

Tissue-related causes involve problems with the placenta itself. If small pieces of the placenta or membranes remain attached to the uterine wall after delivery, this retained tissue prevents the uterus from contracting effectively and leads to continued bleeding. Additionally, abnormal placentation such as placenta accreta spectrum (when the placenta attaches too deeply into the uterine wall) can cause the placenta to fail to detach properly, resulting in severe haemorrhage.^[5]

Trauma during delivery represents another major cause. For women who have vaginal births, tears or cuts in the cervix, vagina, or perineum can lead to significant bleeding. Deliveries that require the use of forceps or vacuum assistance carry higher risk of these injuries. Caesarean deliveries can also contribute to trauma if blood vessels or organs in the abdomen are accidentally injured during surgery, particularly in emergency situations or when there are dense adhesions from previous surgeries.^[5]

The fourth category, thrombin, refers to problems with blood clotting. Some women have pre-existing clotting disorders such as von Willebrand disease or idiopathic thrombocytopenic purpura that can contribute to excessive bleeding. Others may develop clotting problems during pregnancy or labor, such as disseminated intravascular coagulation (a serious condition where blood clots form throughout the body), which can occur secondary to complications like placental abruption, severe preeclampsia, or sepsis.^[5]

Risk Factors

While any woman can experience postpartum haemorrhage, certain conditions and circumstances increase the likelihood of this complication occurring. It’s crucial to understand that approximately 20 percent of postpartum haemorrhage cases happen in women with no identifiable risk factors, which is why healthcare providers must be prepared to manage this condition at every delivery.^[9]

Conditions affecting the placenta significantly increase risk. Placental abruption (when the placenta detaches from the uterus before delivery) and placenta previa (when the placenta covers or sits near the cervical opening) are both associated with higher rates of postpartum bleeding. Women with these conditions are typically identified during pregnancy through ultrasound examinations.^[4][7]

An overdistended uterus creates conditions that make it harder for the uterus to contract effectively after delivery. This can occur when there’s too much amniotic fluid surrounding the baby, when carrying twins or triplets, or when the baby is particularly large (especially over 4,000 grams or 8.8 pounds). The stretched uterine muscle simply doesn’t contract as efficiently after birth.^[4]

Labor-related factors also play a role. Women who experience prolonged labor or very rapid labor face increased risk. Those whose labor is induced or augmented with medications like oxytocin may be at higher risk, particularly if the medication is used for an extended period. Having had many previous births can also affect how well the uterus contracts after delivery.^[5][9]

Other medical conditions that affect bleeding and clotting also increase risk. Pre-existing bleeding disorders need to be identified and managed before delivery. Antepartum haemorrhage (bleeding during pregnancy) suggests potential problems that may continue after birth. First-time mothers appear to face slightly higher risk compared to women who have given birth before, though the reasons for this aren’t entirely clear.^[9]

Interestingly, some risk factors are related to ethnicity, though the underlying reasons require further study. Women of Asian or Hispanic ethnic background have been noted to have somewhat higher rates of postpartum haemorrhage, though this may reflect a complex interaction of genetic, healthcare access, and other social factors.^[8]

Symptoms

Recognizing the signs of postpartum haemorrhage quickly is essential for ensuring prompt treatment and preventing serious complications. The symptoms can develop immediately after delivery or may not appear until hours or even weeks later, which is why it’s important to know what to watch for even after leaving the hospital.^[1]

The most obvious symptom is persistent, excessive vaginal bleeding after delivery. While some bleeding is completely normal after giving birth, with postpartum haemorrhage the bleeding is much heavier than expected and doesn’t slow down. Women may pass large blood clots, and anything larger than a golf ball should be considered a warning sign that needs immediate medical attention.^[1]

As blood loss continues, the body begins to show signs that it’s losing too much blood. Women may experience dizziness or feel like they’re going to faint. Vision can become blurry, making it difficult to focus on objects. These symptoms occur because the drop in blood pressure reduces blood flow to the brain and other vital organs.^[1]

The heart tries to compensate for blood loss by beating faster, so an increased heart rate is another common symptom. Women might notice their heart racing or pounding in their chest. The skin may become pale or feel cold and clammy to the touch as the body redirects blood flow to vital organs.^[1][8]

Some women experience pain and swelling in the vaginal or perineal area. This can occur when blood collects outside of blood vessels in the tissues, forming what’s called a hematoma. The pain may be severe and the swelling visible or palpable.^[1]

Less common symptoms include nausea and vomiting. Some women feel extremely weak or tired beyond the normal exhaustion of childbirth. They may feel confused or have trouble thinking clearly. In severe cases, women can develop shortness of breath or chest pain as the body struggles with decreased blood volume and oxygen delivery.^[7]

For secondary or late postpartum haemorrhage, which occurs more than 24 hours after delivery, symptoms may include a sudden return of heavy bleeding after it had slowed down, or the passage of tissue or large clots. Some women may develop a fever if infection is contributing to the bleeding. Any concerning symptoms in the days or weeks after giving birth warrant immediate contact with a healthcare provider.^[1]

Prevention

While it’s not possible to prevent all cases of postpartum haemorrhage, there are proven strategies that significantly reduce its occurrence and severity. These preventive measures are now considered standard practice in most modern delivery settings.^[9]

The most important preventive intervention is called active management of the third stage of labor. The third stage refers to the time between delivery of the baby and delivery of the placenta. Active management involves giving a medication that helps the uterus contract immediately after the baby is born, typically as the baby’s anterior shoulder is being delivered. This practice has been shown to decrease the risk of postpartum haemorrhage significantly.^[9]

The medication most commonly used for prevention is oxytocin, which is more effective than other options and has fewer side effects. Oxytocin helps the uterus contract strongly, which compresses the blood vessels where the placenta was attached and reduces bleeding. This medication has been proven effective even in women who already received oxytocin during labor for induction or augmentation.^[9]

Another preventive measure involves avoiding unnecessary episiotomy. An episiotomy is a surgical cut made in the perineum to widen the vaginal opening during delivery. Routine episiotomy has been shown to increase blood loss and the risk of serious tears that extend to the anal sphincter. Therefore, episiotomy should only be performed when urgent delivery is necessary and the perineum is thought to be limiting the baby’s birth.^[9]

For women at high risk of postpartum haemorrhage, planning is crucial. These women should be advised to give birth in a hospital setting that has immediately available surgical capabilities, intensive care units, and blood bank services. Having these resources readily accessible can be lifesaving if severe haemorrhage occurs.^[9]

Healthcare facilities can prepare for potential haemorrhage by having standardized protocols in place. This includes maintaining a haemorrhage cart with necessary medications, supplies, checklists, and instruction cards immediately available. Establishing a clear response team and ensuring everyone knows who to call when help is needed creates an environment where haemorrhage can be managed quickly and effectively.^[9]

During pregnancy, treating conditions like anaemia can help women tolerate blood loss better if it occurs. Women who are anaemic going into delivery have less reserve and are more vulnerable to the effects of even moderate blood loss. Identifying and treating bleeding disorders before delivery is also important for prevention.^[7]

Pathophysiology

Understanding what happens in the body during postpartum haemorrhage helps explain why this condition is so serious and why rapid treatment is essential. The pathophysiology involves a cascade of events that, if not interrupted quickly, can lead to life-threatening complications.^[1]

Normally, blood loss during childbirth is regulated by two main mechanisms: uterine contractions and the body’s natural blood clotting system (the coagulation cascade). After the baby is born, the uterus should contract firmly, squeezing shut the blood vessels where the placenta was attached. At the same time, the blood clotting system forms plugs in these vessels to stop bleeding. When either or both of these mechanisms fail, excessive bleeding occurs.^[2]

In cases of uterine atony, the uterine muscle fibers fail to contract adequately. Without this contraction, the blood vessels that supplied the placenta remain open and bleed freely. During pregnancy, approximately 500 to 800 milliliters of blood flows through the uterus every minute, so when these vessels aren’t compressed, blood loss can be massive and rapid.^[4]

As blood volume drops, the body experiences decreased blood pressure. Initially, the body tries to compensate by increasing heart rate and redirecting blood flow away from less critical areas like the skin and extremities toward vital organs like the heart and brain. This is why women with postpartum haemorrhage often have pale, clammy skin and rapid heartbeats.^[1]

If bleeding continues unchecked, the woman can develop hypovolemic shock, which occurs when organs don’t receive enough blood flow to function properly. The heart struggles to pump effectively with reduced blood volume. The brain doesn’t receive adequate oxygen, leading to confusion and loss of consciousness. The kidneys can fail, unable to filter blood and produce urine. The liver and other organs also begin to fail.^[1]

Massive blood loss can trigger a dangerous condition called dilutional coagulopathy. As the body loses blood, it’s replaced with intravenous fluids and blood products, but if the replacement isn’t balanced correctly, the concentration of clotting factors becomes diluted. This makes it even harder for the body to stop bleeding, creating a vicious cycle where blood loss worsens clotting ability, which leads to more blood loss.^[9]

The body’s response to haemorrhage involves multiple organ systems. The kidneys may stop producing urine as blood flow decreases. The lungs can develop acute respiratory distress syndrome (severe lung inflammation and fluid accumulation). The heart may experience ischemia (inadequate oxygen supply) if blood pressure drops too low. These complications explain why postpartum haemorrhage remains a leading cause of maternal death and severe maternal morbidity worldwide.^[3]

In cases where tissue retention contributes to haemorrhage, pieces of placenta or membranes remaining in the uterus prevent the organ from contracting effectively. These retained products also provide a surface for continued bleeding and can become a source of infection, further complicating recovery.^[4]

When trauma causes postpartum haemorrhage, the pathophysiology is more straightforward but equally serious. Tears in blood vessels or lacerations of the genital tract create direct pathways for blood loss. Large tears can damage major blood vessels, leading to rapid and severe haemorrhage. Hidden bleeding into tissues (hematomas) may not be immediately visible but can result in significant blood loss and compression of surrounding structures, causing pain and additional complications.^[5]