Postpartum haemorrhage

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Your Organisational Guidance

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Multidisciplinaire richtlijn Postpartumzorg in de eerste lijn (deel 1)Published by: Werkgroep Ontwikkeling Richtlijnen Eerste Lijn (Worel)Last published: 2022Guideline multidisciplinaire des soins postnatals dans la première ligne de soins (partie 1)Published by: Groupe de Travail Développement de recommmandations de première ligneLast published: 2022Multidisciplinaire richtlijn Postpartumzorg in de eerste lijn (deel 2)Published by: Werkgroep Ontwikkeling Richtlijnen Eerste Lijn (Worel)Last published: 2024Guideline multidisciplinaire des soins postnatals dans la première ligne de soins (partie 2)Published by: Groupe de Travail Développement de recommmandations de première ligneLast published: 2024

General principles

PPH is an obstetric emergency.

Early diagnosis relies on accurate quantification of blood loss as well as frequent assessment of patient-specific risk factors, vital signs, and clinical symptoms and signs of haemorrhage.[3][4][52]

The goal is to recognise PPH before any deterioration in vital signs and ensure timely intervention to control blood loss.
Early identification of high-risk patients during the antenatal period is vital in mitigating potential delays in delivering appropriate care and enabling swift responses during critical situations, thereby fostering improved maternal outcomes.

Since derangements of vital signs may only become apparent in later stages of PPH, continued meticulous assessment of ongoing blood loss is paramount.[3][4][36][53]

Ensure frequent ongoing monitoring of vital signs to assess for haemodynamic instability and hypovolaemic shock.
Manage any signs of hypovolaemic shock with emergent resuscitation measures.

Primary PPH occurs within 24 hours of delivery and accounts for the vast majority of cases. Secondary PPH occurs >24 hours and up to 12 weeks postpartum and accounts for 1% to 2% of cases.[3][21]

History

Make a clinical diagnosis of primary PPH based on an estimated blood loss (EBL) ≥500 mL within 24 hours of birth.[4][5][36]

Categorise PPH as minor (EBL 500-1000 mL) or major (EBL >1000 mL).
Major PPH may be moderate (EBL 1000-2000 mL) or severe (EBL >2000 mL).

Be aware that the degree of EBL that warrants a diagnosis of primary PPH varies between guidelines. Check your local protocol.

Primary PPH was traditionally defined as EBL >1000 mL following caesarean delivery or >500 mL after a vaginal birth.[1][2][3]
Guidelines from the UK Royal College of Obstetricians and Gynaecologists (RCOG) define primary PPH as the loss of ≥500 mL from the genital tract within 24 hours of birth.[4] This definition is endorsed by the World Health Organization (WHO).[5]
By contrast, the American College of Obstetricians and Gynecologists (ACOG) now endorses the reVITALIZE criteria for diagnosing primary PPH.[3] These criteria define primary PPH as an EBL ≥1000 mL regardless of mode of delivery OR any volume of blood loss accompanied by signs and symptoms of hypovolaemia within 24 hours of birth.[6] These updated diagnostic criteria are intended to promote early detection of PPH by tackling visual underestimation of EBL and placing equal focus on clinical symptoms and signs of haemorrhage.[1][6]

Ensure your assessment of PPH incorporates both EBL and clinical signs/symptoms of blood loss. Do not rely solely on either alone.[3][4][36][70]

Be aware that assessment of vital signs remains a crucial element in early detection of PPH since visual estimation of blood loss often underestimates the extent of haemorrhage.[4][71]
- The following are all signs of acute blood loss: tachycardia (heart rate >100 beats per minute); hypotension (systolic blood pressure [SBP] <90 mmHg); tachypnoea (respiratory rate >20 breaths per minute); decreased urine output; decreased pulse pressure (the difference between systolic and diastolic pressures: normally 35-45 mmHg).[3][6][72]
Conversely, if PPH is clinically suspected based on EBL, start immediate treatment even if the patient has normal vital signs.[3][70]
- The association between vital sign thresholds and degree of haemorrhage is more variable in obstetric patients compared with the general adult population because of the physiological increase in circulating blood volume.[4] Derangements of vital signs are often a late manifestation of significant blood volume loss and hypovolaemic shock.[73][74]
- In pregnancy, traditional signs of hypovolaemia such as heart rate and blood pressure are normally maintained in the normal range until blood loss exceeds 1000 mL; tachycardia, tachypnoea, and a slight fall in SBP occur with blood loss of 1000-1500 mL; a SBP <80 mmHg, associated with worsening tachycardia, tachypnoea, and altered mental state, usually indicates a PPH >1500 mL.[4][36]

Early warning criteria

Various maternal early warning scores exist and can provide an obstetric-specific set of abnormal parameters that indicate the need for urgent bedside evaluation to identify and recognise obstetric emergencies, including haemorrhage. Check your local protocol for details of which score to use.

Examples of maternal early warning scores include:

NHS England’s national Maternity Early Warning Score (MEWS), which started roll-out in 2023 to replace a variety of modified scores used in different institutions.[75] The scoring system and response triggers are summarised in the diagrams below.[76]
[Figure caption and citation for the preceding image starts]: NHS England Maternity Early Warning ScoreNHS England. National Patient Safety Improvement Programmes: early Recognition and Management of Deterioration of Women and Babies (https://www.patientsafetyoxford.org); used with permission [Citation ends].
Scotland has its own national Maternity Early Warning System.[77]
In the US, the Maternal Early Warning Criteria encompass changes in blood pressure (systolic or diastolic), heart rate, respiratory rate, oxygen saturation, urine output, and maternal confusion or unresponsiveness.[78]

In addition, the shock index (SI) can serve as a predictive indicator of haemodynamic changes resulting from acute blood loss, even when blood pressures remain within the normal range.[4][74][79][80]

The SI is calculated by dividing the maternal heart rate by the SBP.
SI values above 0.9 have been associated with an increased risk of requiring massive transfusion, admission to the intensive care unit, and adverse outcomes related to PPH.

Risk factors for PPH

Consider the following risk factors for PPH based on the patient's history and clinical course:[3][7][21][36][53]

Placenta previa/low lying placenta
Placenta accreta spectrum
Thrombocytopenia
Active bleeding during labour and delivery
Maternal coagulopathy (inherited or acquired)
History of PPH >1000 mL or requiring blood transfusion in prior delivery
Prior caesarean delivery, uterine surgery, or multiple laparotomies
Uterine overdistension: multiple gestation, polyhydramnios, fetal macrosomia with estimated fetal weight (EFW) >4000 g
Grand multiparity (>4 prior births)
Large uterine myomas
Class III obesity (BMI >40 kg/m²)
Known maternal anaemia
Prolonged labour or precipitous delivery
Labour induction or augmentation with prolonged use of oxytocin
Magnesium sulfate use
Caesarean delivery
Operative (assisted) vaginal delivery
Placental abruption
Current use of therapeutic anticoagulation
Severe pre-eclampsia or HELLP syndrome
Intrauterine fetal demise (IUFD)
Intrapartum infection (chorioamnionitis or endometritis)
Use of a selective serotonin-reuptake inhibitor or serotonin-noradrenaline reuptake inhibitor (SSRI/SNRI) antidepressant in the month before delivery.

Be aware that many birthing patients who experience PPH do not have any of these risk factors.[3][21]

It is important to assess risk on an ongoing basis both antenatally and upon admission, with adjustments made as additional risk factors emerge during labour or the postpartum period.[52] For more details on risk assessment tools, see Primary prevention.

See Risk factors.

Presentation of secondary PPH

Secondary PPH is defined as excessive bleeding that occurs more than 24 hours after delivery and up to 12 weeks postpartum.[4] It may be associated with:[3]

Subinvolution of the placental site
Retained products of conception
Infection
Inherited coagulation defects (e.g., factor deficiency such as von Willebrand). In some cases, secondary PPH may be the first presentation of a bleeding disorder.

Strongly suspect endometritis as the cause if the woman presents with uterine tenderness and a low-grade fever or other signs of infection.[3][21]

Physical examination

Ensure a meticulous physical examination of the uterus, cervix, vagina, vulva, and perineum to facilitate an accurate diagnosis and prompt treatment of the underlying cause of PPH.[3][4]

Be aware of the most common causes of PPH, which are classified by the 'four Ts' mnemonic:[3][4][20]

Tone - uterine atony is the most common cause of PPH, accounting for approximately 70% to 80% of cases.[3][20] It can be associated with intrapartum infection (chorioamnionitis or endometritis).[21]
Trauma - is the second most common cause of PPH, present in 20% to 30% of cases.[20] Maternal trauma is indicated by the presence of obstetric lacerations, expanding haematomas, or suspected uterine rupture.[3]
Tissue - retained placenta/membrane or placenta accreta spectrum is the third most common cause of PPH, present in 10% of cases.[3][20]
Thrombin - acquired or inherited coagulopathy accounts for <1% of cases of PPH.[3][20]
Note that more than one of the above causes can be present in any individual case of PPH.

Suspect uterine atony first as the most likely underlying aetiology of PPH.[3]

However, if bleeding is ongoing and uncontrolled, do not delay the decision to move the patient to the operating room for better visualisation and/or administration of anaesthesia as a traumatic cause may be present.

Perform a bimanual examination with abdominal fundal palpation to evaluate the tone of the uterus.[5]

A soft, poorly contracted (boggy) uterus above the level of the umbilicus despite uterine massage is diagnostic for uterine atony.[3]
Uterine rupture may be diagnosed postpartum through palpation of a uterine defect on bimanual examination. Note that the most common prior intrapartum symptoms associated with uterine rupture include acute-onset persistent abdominal pain, vaginal bleeding, tachysystole on tocometry, loss of fetal station, and/or a non-reassuring fetal heart rate tracing in the setting of a prior uterine scar.[81]
If the uterine fundus cannot be palpated during a PPH, consider evaluating for uterine inversion, as incomplete or partial uterine inversion may not be immediately recognised on initial examination. A mass may or may not be palpated within the uterus, or visualised protruding from the vagina, representing the uterine fundus. These patients may experience significant shock or hypotension out of proportion to the degree of blood loss, due to vasovagal stimulation.[82]

Ensure a thorough examination of the abdomen and pelvis that allows for proper visualisation of the cervix and the entire length of the vaginal walls.[3][36]

A detailed pelvic examination is required to identify unrepaired cervical, sulcal, or perineal lacerations, as well as expanding pelvic haematomas. Early intervention is paramount to prevent worsening of PPH.
It is important to note that PPH resulting from some forms of trauma (e.g., cervical or high vaginal lacerations) may only be detected during an examination under anaesthesia in the operating room.[83]

Assess for retained products of conception, which complicates approximately 2% to 3% of all births.[84]

Retained placental tissue is diagnosed with careful bimanual examination upon postpartum palpation of placental tissue or membranes within the uterine cavity. Bedside ultrasonography can be used to assess the endometrial stripe for the presence of intrauterine placental tissue.[3]
Inspect the placenta itself to ensure intact placental delivery, and to assess for the presence of missing placental tissue or membranes.[3][21]
- Placenta accreta spectrum (PAS) disorder (placenta accreta, increta, or percreta) may have been diagnosed antenatally on ultrasound and appropriate preparations for delivery should have been made. Have a high suspicion for PAS disorder in any case of morbidly adherent placenta suspected intraoperatively, an inability of the placenta to separate after delivery, or the presence of adherent portions of placental tissue despite manual removal.

In patients with refractory PPH, a laparotomy may be performed to further evaluate the pelvic and abdominal organs and to identify concealed haemorrhage sources such as broad ligament and retroperitoneal haematomas.[82]

Initial investigations

Quantification of blood loss

Use an objective method to measure blood loss (e.g., by weighing blood-soaked drapes or surgical sponges).[71]

Weighing blood-soaked drapes or sponges is a more precise and objective approach that minimizes the risk of underestimating blood loss and facilitates early identification and intervention for PPH.[71][85][86][87]
Visual estimation can result in underestimation of blood loss by 33% to 50%, particularly when large volumes are lost.[4][52]

Objective measurement of cumulative quantitative blood loss (QBL) - including the use of under-buttock drapes during vaginal births and real-time weight measurements of blood-soaked materials - is advocated by the WHO and International Federation of Gynecology and Obstetrics (FIGO) as an essential part of an obstetric haemorrhage detection and management bundle.[12][55][71]

Some studies have cast doubt on the effectiveness of QBL measurements in preventing PPH or improving maternal outcomes.[88][89] There is no robust evidence that specifically demonstrates a reliable correlation between QBL measurements and postpartum haemoglobin measurements.[90]
The E-MOTIVE trial, published in 2023, assessed use of a calibrated drape for early detection of excessive blood loss following vaginal birth among 210,132 women in four African nations. Use of the drapes triggered an immediate treatment bundle for any woman with blood loss of ≥500 mL (as indicated by a red action line on the drapes) or with blood loss ≥300 mL (yellow warning line) together with hypotension or tachycardia. This combined PPH early detection and treatment bundle was associated with a 60% reduction in the composite primary outcome of severe PPH (blood loss ≥1000 mL), or laparotomy or maternal death from PPH (risk ratio 0.40, 95% CI 0.32 to 0.50; P <0.001) when compared with usual care.[91]
In response to the E-MOTIVE findings, the WHO commissioned a systematic review on methods to assess postpartum blood loss. This led to a recommendation to use an objective method to quantify blood loss in all women giving birth, such as calibrated drapes for those having vaginal birth.[71]
The WHO highlighted that to be effective in improving outcomes, objective approaches to quantifying blood loss must be combined with a standardised protocol to ensure prompt initiation of treatment immediately on detection of PPH.[71]
In guidance that predates publication of the E-MOTIVE trial results and the WHO recommendation, the UK RCOG states that use of blood collection drapes for vaginal deliveries and the weighing of swabs is an option to address visual underestimation of blood loss.[4]

The ACOG has published tips for quantification of blood loss following vaginal and caesarean delivery.[92]

Create a list of dry weights for delivery items that may become blood-soaked. These weights can then be subtracted from the wet weight to quantify blood loss. Assume 1 gram weight = 1 mL blood loss volume.
During vaginal delivery
- Begin quantification of blood loss immediately after the infant's birth (before delivery of the placenta) and assess and record the amount of fluid collected in a calibrated under-buttocks drape.
- Be aware that most fluid collected before placenta delivery is amniotic fluid, urine, and faeces, whereas most of that collected after placenta delivery is blood. If irrigation is used, subtract that from the total fluid collected.
- Record the total volume collected in the under-buttocks drape.
- Subtract the pre-placental from the post-placental fluid volume to determine blood loss more accurately.
- Weigh all blood-soaked materials and clots and convert to mL of blood loss.
- Add the fluid volume collected in the drapes to the blood volume measured by weighing soaked items to quantify the blood loss.
During caesarean birth
- Begin quantification of blood loss when the amniotic membranes are ruptured or after the infant is born.
- Suction and measure all amniotic fluid within the suction canister of collected fluid before placental delivery.
- After placental delivery, measure the amount of blood loss in the suction canister and drapes. Document the amount of blood loss in mL.
- Ensure the scrub team communicates when irrigation is beginning. Remember some of the saline will be absorbed into tissues, hence not all the fluid will be suctioned from the abdomen and accounted for. To suction the irrigation fluid, either continue to suction into the same canister and measure the amount of irrigation fluid or use another suction tube to collect the irrigation in a separate container.
- Weigh all blood-soaked materials and clots and convert to mL of blood loss. Note that lap pads dampened with saline contain minimal fluid, hence treat them in the same way as other dry item weights.
- Add the volume of blood collected in the drapes and other items to the volume of blood in the suction canister to quantify total blood loss.

Other initial investigations

Order a blood test in all patients with suspected PPH including full blood count plus blood type and cross-match.[4][21][53]

Send a stat blood sample for type and cross-match for any patient with suspected PPH, to facilitate timely administration of blood product replacement, if indicated.
Notify the blood bank so that at least 2 units of blood can be type and cross-matched for the patient.[21]
Bear in mind that on admission to labour and delivery, an initial type and screen should have been ordered for any patient deemed to be at medium risk for PPH and a type and cross should have been sent for any patient deemed high risk.[7][8]

Request coagulation profile analysis in any case of significant PPH.[2][4][53] Early identification of coagulation abnormalities can aid in the timely administration of appropriate blood products or adjunctive medical therapies.[21]

Thrombin (clotting factor deficiency) is the underlying cause of <1% of cases of PPH.[3][20]
Fibrinogen levels increase during pregnancy to around 4-6 g/L by the time of delivery, hence a level of 2-3 g/L (which would be reassuring in a non-pregnant patient) indicates significant blood loss in PPH.[2]
If disseminated intravascular coagulation (DIC) or another acquired or inherited coagulopathy is suspected, evaluation of the patient's coagulation status is especially crucial.[21] Request serum profiles to assess prothrombin time (PT), partial thromboplastin time (PTT), international normalised ratio (INR), and fibrinogen to confirm the diagnosis.

Further investigations

Uterine ultrasound can be used to assess for retained products of conception, although the diagnosis of retained products is unreliable.[3][4][93]

Bedside ultrasonography can be used to assess the endometrial stripe for an echogenic mass, strongly indicating the presence of intrauterine placental tissue.[3]
Ultrasound is particularly important in investigation of secondary PPH, which can be caused by retained products of conception.

[Figure caption and citation for the preceding image starts]: Ultrasound image showing retained product of conception within the endometrial cavity (measuring 20 x 8mm) in a woman with secondary PPH. The image was taken on day 22 post-deliveryDu R, et al. BMJ Case Reports CP 2021;14:e245009; used with permission [Citation ends]. com.bmj.content.model.Caption@2807a75e

In haemodynamically stable patients in whom conventional medical treatment has failed to stop the bleeding, further evaluation with computed tomography (CT) with intravenous contrast can be considered, particularly in suspected intra-abdominal haemorrhage or post-surgical complications.[93]

In women presenting with secondary PPH, ensure an assessment of vaginal microbiology with high vaginal and endocervical swabs.[4]

Emerging investigations

Thromboelastography (TEG) and rotational thromboelastometry (ROTEM®) are rapid point-of-care tests that can aid in the evaluation of coagulopathy. They are increasingly used in obstetric facilities to guide transfusion needs and elucidate the underlying factors contributing to coagulopathy in patients experiencing PPH.[94][95]

Standard coagulation assays performed on plasma have limitations in assessing clinically significant coagulopathy caused by ongoing blood loss and specific coagulation factors such as factor XIII, platelet function, and fibrinolytic system activity.[94][95]
TEG and ROTEM® offer distinct advantages over standard assays by enabling the evaluation of coagulation using whole blood, including assessment of platelet function and the timing and extent of fibrinolysis. This rapid and precise detection of coagulation abnormalities can be invaluable in cases of ongoing PPH.[96][97][98]
However, the use of TEG and ROTEM® is currently limited by the absence of standardised normal reference ranges, making it challenging to interpret results and compare them between different healthcare settings. Variations in baseline parameters for specific obstetric populations further contribute to the complexity of accurate interpretation.[96][97][98][99]

Innovative app-based techniques supported by artificial intelligence (e.g., the US Food and Drug Administration-approved Triton System™) have emerged to enhance the measurement of ongoing blood loss. Leveraging mobile monitoring capabilities, the Triton System™ captures images of blood-soaked surgical materials and employs feature extraction technology to provide accurate haemoglobin measurements.[100][101] While the potential benefits of this technology are promising, its long-term efficacy in the context of obstetric care requires further evaluation.