INTRODUCTION — HELLP is an acronym that refers to a syndrome in pregnant and postpartum individuals characterized by hemolysis with a microangiopathic blood smear, elevated liver enzymes, and a low platelet count [1]. It probably represents a severe form of preeclampsia (table 1A-B), but the relationship between the two disorders remains controversial. HELLP may be a separate disorder from preeclampsia because as many as 15 to 20 percent of patients with HELLP do not have antecedent hypertension or proteinuria [2-4].
Birth eventually leads to resolution of signs and symptoms of HELLP. Maternal complications are primarily related to bleeding, which can include hepatic hemorrhage. Neonatal complications are primarily related to the gestational age at birth, which is commonly preterm.
This topic will focus on the clinical presentation, diagnosis, differential diagnosis, and management of HELLP syndrome. Preeclampsia is reviewed in detail separately.
●(See "Preeclampsia: Clinical features and diagnosis".)
●(See "Preeclampsia: Antepartum management and timing of delivery".)
●(See "Preeclampsia with severe features: Expectant management remote from term".)
PREVALENCE — HELLP develops in 0.1 to 1.0 percent of pregnant people overall. Among patients with severe preeclampsia/eclampsia, 1 to 2 percent have microangiopathic hemolysis and thus can be considered to have HELLP.
RISK FACTORS — Risk factors include a previous history of preeclampsia or HELLP. (See 'Recurrence in subsequent pregnancies' below.)
A variety of genetic variants associated with an increased risk for HELLP has been reported, but they have no role in clinical management [5]. (See 'Pathogenesis' below.)
In contrast to preeclampsia, nulliparity is not a risk factor for HELLP [6]. Multiparous individuals account for ≥50 percent of affected patients.
PATHOGENESIS — The pathogenesis of HELLP is unclear. If it is a severe form of preeclampsia, it likely has the same origin (see "Preeclampsia: Pathogenesis"). If it is a separate entity, it can still have a similar origin, but it then diverges along a different pathway for unknown reasons such that there is greater hepatic inflammation and greater activation of the coagulation system than in preeclampsia [5,7,8].
A subset of HELLP may be related to thrombotic microangiopathy caused by complement dysregulation, which may be treatable without prompt delivery of the fetus. In a case report of a patients with severe early HELLP, treatment with eculizumab, a targeted inhibitor of complement protein C5, was associated with marked clinical improvement and complete normalization of laboratory parameters for 16 days, after which HELLP recurred [9]. The authors chose this intervention based on the hypothesis that severe preeclampsia/HELLP is a systemic inflammatory disorder and the complement cascade is a key mediator, and the observation that females with mutations in complement regulatory proteins appear to be at increased risk of severe preeclampsia [10]. Further research of possible benefits and harms is warranted [11].
In less than 2 percent of patients with HELLP, the underlying etiology appears to be related to fetal long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) deficiency [12,13]. In one case series, all six pregnancies with fetal LCHAD deficiency developed severe maternal liver disease (HELLP or acute fatty liver of pregnancy [AFLP]) [14]. These complications probably were not due to chance or maternal heterozygosity for LCHAD deficiency alone because three other pregnancies with unaffected fetuses among these mothers were uncomplicated. In another case series in which 19 fetuses had LCHAD deficiency, 15 mothers (79 percent) developed AFLP or the HELLP syndrome during their pregnancies [15]. Although these findings inform theories about the pathogenesis of HELLP, evaluation for genetic variants associated with LCHAD deficiency has no role in clinical management of patients with HELLP. (See "Acute fatty liver of pregnancy", section on 'Fetal long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) deficiency'.)
PATHOPHYSIOLOGY — Microangiopathy and activation of intravascular coagulation can account for all of the laboratory findings in HELLP syndrome. Hepatic histology may show microvascular fibrin deposition, neutrophilic infiltrate, fatty infiltration, lobular necrosis, and periportal hemorrhage (picture 1) [16]. Although renal dysfunction is not an essential diagnostic criterion, microvascular dysfunction may also occur in the kidney and may increase its vulnerability to an ischemic insult [17].
PATIENT PRESENTATION
Signs and symptoms — HELLP has a variable presentation (table 2) [18]. The onset of symptoms is usually rapid, and the symptoms progressively worsen.
Abdominal pain, which may be colicky, is the most common symptom and is present in most patients. It may be localized to the midepigastrium, right upper quadrant, or below the sternum and the area may be tender on physical examination [19]. Many patients also have nausea, vomiting, and generalized malaise, which may be mistaken for a nonspecific viral illness or viral hepatitis, particularly if the serum aspartate aminotransferase and lactate dehydrogenase levels are markedly elevated. Less common symptoms include headache, visual changes, jaundice, and ascites.
On physical examination, hypertension (defined as blood pressure ≥140/90 mmHg) and proteinuria are present in approximately 85 percent of cases, but it is important to note that either or both may be absent in patients with otherwise severe HELLP syndrome [18].
Serious maternal morbidity may be present at initial presentation or develop shortly thereafter. This includes placental abruption, acute kidney injury, pulmonary edema, subcapsular or intraparenchymal liver hematoma, and retinal detachment [19]. Disseminated intravascular coagulation (DIC), if present, is usually seen in association with abruption, severe peripartum bleeding, or fulminant liver failure. (See 'Maternal outcome' below.)
Thrombocytopenia-related bleeding (mucosal, hematuria, petechial hemorrhages, ecchymosis) is an unusual presentation [18].
Gestational age at onset — Symptoms typically develop between 28 and 37 weeks of gestation, but onset in the late second trimester or at term/postpartum is also common. In a large series including over 440 pregnancies complicated by the HELLP syndrome, 70 percent occurred before birth, approximately 80 percent of these cases occurred before <37 weeks, and fewer than 3 percent occurred between 17 and 20 weeks [19].
In the 30 percent of cases that occurred postpartum, most were diagnosed within 48 hours after birth, but occasionally as long as seven days; 80 percent had evidence of preeclampsia before birth. Why some cases of HELLP and preeclampsia develop postpartum is unknown and confusing since delivering the placenta initiates resolution of the disease in most patients.
DIAGNOSTIC EVALUATION — In pregnant individuals with characteristic symptoms of HELLP (eg, right upper quadrant/midepigastric pain, nausea, vomiting, generalized malaise) and/or new onset hypertension in the second half of pregnancy or first postpartum week, we obtain the laboratory tests that establish/exclude the diagnosis of HELLP. Because pain may precede laboratory abnormalities by several hours, repeating the laboratory tests in four to six hours can be helpful unless another cause for pain has been determined [20].
Laboratory work-up includes [18]:
●Complete blood count
●Peripheral smear
●Aspartate aminotransferase, alanine aminotransferase, bilirubin
●Creatinine
●In patients with elevated liver chemistries, the author also obtains haptoglobin and lactate dehydrogenase levels and coagulation studies (fibrinogen, prothrombin time, activated partial thromboplastin time).
DIAGNOSIS — The diagnosis of HELLP is based upon the presence of all of the laboratory abnormalities comprising its name (hemolysis with a microangiopathic blood smear [fragmented red blood cells; ie, schistocytes, burr cells], elevated liver enzymes, and low platelet count) in a pregnant/postpartum patient.
Pregnant/postpartum patients who have some of the typical laboratory abnormalities but do not meet all of the laboratory criteria described below are considered to have partial HELLP [6]. These patients may progress to meet all criteria.
Laboratory criteria for diagnosis — We require the presence of all of the following criteria to diagnose HELLP (Tennessee classification) [21]:
●Hemolysis, established by at least two of the following:
•Peripheral smear with schistocytes and burr cells (picture 2)
•Serum bilirubin ≥1.2 mg/dL (20.52 micromol/L)
•Low serum haptoglobin (≤25 mg/dL) or lactate dehydrogenase (LDH) ≥2 times the upper level of normal (based on laboratory-specific reference ranges)
•Severe anemia, unrelated to blood loss
●Elevated liver enzymes:
•Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥2 times the upper level of normal (based on laboratory-specific reference ranges)
●Low platelets: <100,000 cells/microL
The use of twice the upper limit of normal threshold was chosen, in part, to avoid problems related to differences in assays, which may result in an elevated absolute value in one hospital that is considered near normal in another.
In HELLP, an elevated LDH level is a nonspecific marker that can be associated with severe hemolysis, acute hepatocellular injury, or both. The total bilirubin level is increased as a result of an increase in the indirect (unconjugated) fraction from hemolysis. Haptoglobin level is a specific marker of hemolysis: 25 mg/dL provides the best cutoff between hemolytic and non-hemolytic disorders. (See "Diagnosis of hemolytic anemia in adults", section on 'High LDH and bilirubin; low haptoglobin'.)
Severe anemia in pregnancy can be defined as hemoglobin level <8 to 10 g/dL, depending on the trimester. (See "Anemia in pregnancy", section on 'Definition of anemia'.)
The American College of Obstetricians and Gynecologists suggests slightly different diagnostic criteria and acknowledges the absence of clinical consensus among experts [22]:
●LDH ≥600 IU/L, and
●AST and ALT elevated more than twice the upper limit of normal, and
●Platelet count <100,000 cells/microL
Subclassification — Although not commonly used, some clinicians subclassify HELLP based on severity of thrombocytopenia (Mississippi classification) [23]:
●Class 1 – Platelet count ≤50,000 cells/microL plus LDH >600 IU/L and AST or ALT ≥70 IU/L
●Class 2 – Platelet count >50,000 but ≤100,000 cells/microL plus LDH >600 IU/L and AST or ALT ≥70 IU/L
●Class 3 – Platelet count >100,000 but ≤150,000 cells/microL plus LDH >600 IU/L and AST or ALT ≥40 IU/L
DIFFERENTIAL DIAGNOSIS — HELLP may occasionally be confused with other diseases complicating pregnancy. The four major disorders in differential diagnosis are acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, pregnancy-related hemolytic-uremic syndrome, and systemic lupus erythematosus (table 3A-B). There is also overlap with preeclampsia with severe features, which may not be a separate disease. In HELLP, angiopathy and liver dysfunction are marked, and the magnitude of hypertension is not highly correlated with the level of angiopathy and liver dysfunction. By contrast, most cases of severe preeclampsia have severe hypertension; thrombocytopenia and liver dysfunction, although present, are not as markedly abnormal as in HELLP. However, the clinical and histologic features are so similar that establishing the correct diagnosis may not be possible; furthermore, HELLP can occur concurrently with these disorders.
Likewise, SARS-CoV-2 infection during pregnancy has been associated with a significant increase in the odds of preeclampsia with severe features, eclampsia, and HELLP syndrome [24]. The laboratory abnormalities of COVID-19 and HELLP can overlap, making diagnosis of HELLP difficult in infected patients. (See "COVID-19: Overview of pregnancy issues", section on 'Risk of preeclampsia'.)
Differential diagnosis is discussed in more detail separately. (See "Hypertensive disorders in pregnancy: Approach to differential diagnosis".)
MANAGEMENT OF PATIENTS PRESENTING BEFORE DELIVERY — The initial steps in management are to evaluate the patient as described above (see 'Diagnostic evaluation' above), stabilize those who are unstable, and assess fetal status (nonstress test and ultrasound examination for biophysical profile and fetal presentation).
Because of the potential for severe maternal complications, which can develop rapidly, patients with HELLP should be managed at a tertiary care center with appropriate levels of maternal and neonatal intensive care, when possible.
Patients requiring urgent assessment or intervention
●Patients with severe hypertension should receive antihypertensive therapy (eg, intravenous labetalol (table 4)) promptly to reduce the risk of stroke. The approach to antihypertensive therapy is the same as that for preeclampsia. (See "Treatment of hypertension in pregnant and postpartum patients", section on 'Acute therapy of severe hypertension'.)
●Patients with an abnormal fetal heart rate tracing or low biophysical profile score should be managed according to usual clinical standards. (See "Intrapartum category I, II, and III fetal heart rate tracings: Management" and "Biophysical profile test for antepartum fetal assessment".)
●Patients with severe right upper quadrant/epigastric pain may have hepatic bleeding or hepatic swelling portending liver rupture. The pain may be associated with hypotension and tachycardia; shoulder, back, or neck pain; dyspnea or pain on inspiration; nausea/vomiting; and/or abdominal distention beyond that expected for the pregnant state [25,26]. In a review of 93 cases of hepatic rupture in which almost all were associated with HELLP, 77 percent were associated with abdominal pain, specifically with epigastric and right hypochondrium pain in 64 percent; 24 percent had vomiting, chest, or back pain; 28 percent presented with hemodynamic instability, which was the first clinical manifestation in 29 percent [27]. In a series of 33 HELLP patients complaining of severe right upper quadrant abdominal pain and either shoulder pain, neck pain, or relapsing hypotension, imaging studies revealed an abnormal liver in 45 percent, most commonly subcapsular hematoma and intraparenchymal hemorrhage (image 1 and image 2) [25]. In the overall population of patients with HELLP, however, the incidence of subcapsular hematoma is much less, estimated to be 0.9 to 1.6 percent [19,28].
The aminotransferases in patients with hepatic bleeding are usually modestly elevated, but values of 4000 to 5000 IU/L can occasionally be seen. Because the correlation between the magnitude of laboratory abnormalities and hepatic histology is poor [16], patients with severe symptoms should undergo an appropriate imaging study expeditiously to look for hepatic bleeding, even if liver enzymes are not severalfold above the normal range [21,25,26]. Bedside ultrasound screening (focused assessment with sonography for trauma) is a good initial study, followed by formal ultrasound examination and computed tomography (CT) or magnetic resonance imaging (MRI), when needed for clinical decision making. Imaging using CT or MRI is more dependable than ultrasonography for detecting hepatic hematoma and rupture (image 3 and image 4) but may not be as readily available and CT exposes the fetus to ionizing radiation. (See "Diagnostic imaging in pregnant and nursing patients".)
The hematoma may remain contained, or rupture, with resulting hemorrhage into the peritoneal cavity. Rupture is a life-threatening complication for both the mother and fetus, especially if diagnosis and treatment are delayed. The management of a hematoma is to support the patient with volume replacement and transfusion of blood and blood products, as needed. Prompt delivery is indicated once is the patient is hemodynamically stable and severe anemia and coagulopathy, if present, have been corrected. We stabilize the mother before birth, even in cases with nonreassuring fetal heart rate patterns or a low biophysical profile score.
A team experienced in liver trauma surgery should be consulted during maternal stabilization and prior to delivery [29]. A stable contained hematoma may be managed conservatively. Operative management of an expanding or ruptured hematoma includes packing, drainage, hepatic artery ligation, and/or resection of affected areas of the liver. For patients with intractable hemorrhage despite these interventions, administration of recombinant factor VIIa has been successful in case reports [30]. Liver transplantation because of massive spontaneous hepatic rupture or acute liver failure has been life-saving in case reports [31-34].
Repeat ultrasound evaluation of the liver is performed 48 hours after birth. If stable, repeat testing is performed again in one week and at six weeks postpartum. In general, most patients will be discharged by one week postpartum if the images are stable. If laboratory abnormalities are resolving after birth, the patient may be discharged home with outpatient follow-up. It may take months for a hematoma to resolve completely [21,25].
Surgical intervention in patients who develop a hematoma after birth is indicated in those with hemodynamic instability, persistent bleeding, increasing pain, or continued expansion of the hematoma on serial ultrasound examinations [35]. Percutaneous embolization of the hepatic arteries is a reasonable first-line therapy in patients who are hemodynamically stable [36,37].
There are no ongoing hepatic sequelae following recovery.
●Patients with disseminated intravascular coagulation (DIC), pulmonary edema, or acute kidney injury should be stabilized and delivered.
•(See "Acute respiratory failure during pregnancy and the peripartum period", section on 'Pulmonary edema'.)
•(See "Acute kidney injury in pregnancy".)
Our approach — Our approach is illustrated in the algorithm (algorithm 1).
Intravenous fluids are administered as in patients with preeclampsia. (See "Preeclampsia: Intrapartum and postpartum management and long-term prognosis", section on 'Fluids'.)
Candidates for prompt delivery — The cornerstone of therapy for HELLP occurring during pregnancy is delivery, which is the only effective treatment. There is consensus among experts that prompt delivery is indicated after maternal stabilization for any of the following settings [18,38]:
●Pregnancies ≥34 weeks of gestation.
●Pregnancies that have not reached a stage of fetal maturity that ensures a reasonable chance of extrauterine survival. (See "Periviable birth (limit of viability)".)
●Fetal demise.
●Placental abruption.
In the absence of any of these three scenarios or the urgent clinical scenarios described above (hepatic bleeding, DIC, pulmonary edema, acute kidney injury, abnormal fetal heart rate pattern), delivery may be delayed until a course of antenatal corticosteroids has been administered and completed (ie, 48 hours after the first injection of betamethasone). (See 'Management of candidates for 48 hour delay before delivery' below.)
Magnesium sulfate is given intravenously to patients on the labor and delivery unit to prevent convulsions and for fetal/neonatal neuroprotection in pregnancies between 24 and 32 weeks of gestation with a live fetus. (See "Neuroprotective effects of in utero exposure to magnesium sulfate" and "Preeclampsia: Intrapartum and postpartum management and long-term prognosis", section on 'Regimen'.)
We do not manage patients with HELLP syndrome expectantly at any gestational age and consider conservative management for more than 48 hours investigational. There are few studies on the outcome of expectant management of HELLP syndrome. In these studies, the laboratory abnormalities of HELLP syndrome reversed in a subset of patients managed expectantly, and serious maternal complications were uncommon with careful maternal monitoring and timely intervention. However, the aim of expectant management is to improve neonatal morbidity and mortality. There is no evidence demonstrating improvement in overall perinatal outcome with expectant management compared with pregnancies delivered after a course of antenatal corticosteroids and no maternal benefits from expectant management. The following studies support our approach:
●In a study that treated 128 patients with HELLP <34 weeks of gestation with volume expansion and pharmacologic vasodilation under invasive hemodynamic monitoring, delivery was necessitated in 22 out of 128 (17 percent) of patients within 48 hours; the remaining patients had a median prolongation of pregnancy of 15 days [39]. Although there was no maternal mortality or serious maternal morbidity and more than one-half (55 out of 102) of the patients had complete reversal of their laboratory abnormalities with expectant management, 11 fetal and 7 neonatal deaths occurred.
●In another series, 41 patients with HELLP <35 weeks of gestation were managed expectantly [40]. Delivery was required within 48 hours in 14/41 (34 percent), the remaining patients had a median prolongation of pregnancy of three days, and more than one-half (15/27) had compete reversal of their laboratory abnormalities [40]. However, there were 10 fetal deaths.
Management of candidates for 48 hour delay before delivery
●Betamethasone administration to promote fetal pulmonary maturity – When both the maternal and fetal status are reassuring and the gestational age is above the lower limit of viability and <34 weeks of gestation, we administer a course of betamethasone before delivering pregnancies complicated by HELLP [18,38]. Although a short delay in delivery for betamethasone administration does not appear to increase maternal or fetal morbidity or mortality [41], we advise not attempting to delay delivery beyond 48 hours because disease progression usually occurs, sometimes with rapid maternal deterioration.
We do not give betamethasone for fetal lung maturity in pregnancies with gestational age ≥34 weeks since no patients with HELLP were enrolled in randomized trials of the efficacy of steroids after 34 weeks. During administration of betamethasone, all patients are kept in the labor and delivery unit with continuous fetal monitoring. (See "Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery", section on 'Long-term harms'.)
●Magnesium sulfate is initiated at the time of admission and continued through delivery and the postpartum period to prevent maternal seizures and for fetal/neonatal neuroprotection. (See "Neuroprotective effects of in utero exposure to magnesium sulfate" and "Preeclampsia: Intrapartum and postpartum management and long-term prognosis", section on 'Seizure prophylaxis'.)
●Antihypertensive medication is administered to control severe hypertension (table 4), if present. (See "Treatment of hypertension in pregnant and postpartum patients".)
●The author repeats the complete blood count and platelet count at 24 and 48 hours after administering steroids and more often if clinical deterioration is suspected. The American College of Obstetricians and Gynecologists recommends laboratory testing at least at 12 hour intervals until birth and in the postpartum period [22].
This information is useful when considering whether to administer red blood cell transfusions, whether neuraxial anesthesia can be performed safely (see "Adverse effects of neuraxial analgesia and anesthesia for obstetrics", section on 'Neuraxial analgesia and low platelets'), and whether platelet transfusion is indicated.
Indications for transfusion of blood products
●Red cell transfusion – We transfuse red blood cells if the hemoglobin is <7 g/dL and/or if the patient has ecchymosis, severe hematuria, or suspected abruption.
●Platelet transfusion – Actively bleeding patients with thrombocytopenia should be transfused with platelets. Platelet transfusion may be indicated to prevent excessive bleeding during birth if the platelet count is less than 20,000 cells/microL, but the threshold for prophylactic platelet transfusion in this setting is controversial. The decision depends on patient-specific factors; consultation with the hematology service may be helpful. It is also useful to notify the blood bank that platelet transfusions may be required.
If cesarean birth is planned, platelet transfusion may be required. Some experts recommend platelet transfusion to achieve a preoperative platelet count greater than 40,000 to 50,000 cells/microL [18], but the minimum count before a neuraxial procedure is controversial and depends on factors in addition to platelet concentration. (See "Platelet transfusion: Indications, ordering, and associated risks", section on 'Preparation for an invasive procedure' and "Adverse effects of neuraxial analgesia and anesthesia for obstetrics", section on 'Neuraxial analgesia and low platelets'.)
●Role of therapeutic plasma exchange – Therapeutic plasma exchange has no benefit in patients with HELLP, but is the mainstay of treatment for patients with thrombotic thrombocytopenic purpura (TTP). Because patients with HELLP and those with TTP have both microangiopathic hemolysis and thrombocytopenia, making the correct diagnosis and, in turn, initiating the appropriate treatment can be challenging. Differential diagnosis is discussed in more detail separately. (See "Hypertensive disorders in pregnancy: Approach to differential diagnosis", section on 'Thrombotic microangiopathy: TTP and HUS'.)
Choosing the route of birth — Vaginal birth is desirable in the absence of standard indications for cesarean birth (eg, breech, nonreassuring fetal status). We induce patients with HELLP regardless of gestational age when the cervix is favorable. When the cervix is unfavorable, we believe cesarean birth is probably preferable to induction in pregnancies less than 30 to 32 weeks of gestation, especially if there are signs of fetal compromise (growth restriction, oligohydramnios). Induction of these pregnancies, even with use of cervical ripening agents, generally has a high failure rate and is often prolonged, thereby potentially exposing the mother and fetus to a higher risk of complications from severe HELLP syndrome [18]. (See "Induction of labor with oxytocin" and "Induction of labor: Techniques for preinduction cervical ripening".)
Anesthesia/analgesia — Thrombocytopenia and coagulation abnormalities may preclude use of neuraxial anesthesia for labor and birth. The minimum platelet count necessary to safely perform neuraxial anesthesia is unknown, and practice varies. Use of neuraxial and general anesthesia for these patients is reviewed separately. (See "Anesthesia for the patient with preeclampsia", section on 'Coagulation'.)
Opioids administered intravenously provide some pain relief without risk of maternal bleeding, which may occur with intramuscular administration or with placement of neuraxial anesthesia, removal of a neuraxial catheter, or placement of a pudendal nerve block. However, there is no contraindication to perineal infiltration of an anesthetic for performing an episiotomy or repairing the perineum. (See "Pharmacologic management of pain during labor and delivery".)
Cesarean birth — In patients with severe laboratory abnormalities that are suggestive of liver hematoma, we perform a midline skin incision. After fetal extraction, if preoperative imaging was not performed, the liver may be palpated very gently to assess for the presence of an unruptured hematoma.
Because of the increased risk of subfascial and wound hematoma in patients with thrombocytopenia who undergo cesarean birth, the author places a subfascial drain and leaves the skin incision open for the first 48 postoperative hours [4]. Some surgeons place a subfascial and/or suprafascial drain and close the incision with staples, so it is easy to open partially if a hematoma develops. The management of the abdominal wall incision after cesarean should be individualized, depending on the surgeon's assessment of risk of hematoma/seroma development.
Is there a role for dexamethasone in treatment of HELLP? — We do not treat patients with HELLP syndrome with dexamethasone. The two largest, randomized, double-blind, placebo-controlled trials evaluating the use of dexamethasone to improve maternal outcome in patients with HELLP syndrome did not establish a benefit [42,43], in contrast to initial observational studies and small randomized trials that suggested more rapid improvement in maternal laboratory and clinical parameters [44-47].
In a meta-analysis of 11 trials (550 participants) comparing corticosteroid treatment with placebo/no treatment in HELLP, steroid administration did not lead to a convincing reduction in maternal death (risk ratio [RR] 0.95, 95% CI 0.28-3.21), maternal death or severe maternal morbidity (RR 0.27, 95% CI 0.03-2.12), or perinatal/infant death (RR 0.64, 95% CI 0.21-1.97), but the standardized mean difference in platelet count favored the steroid group (0.67, 95% CI 0.26-1.10) [48].
The use of dexamethasone rather than betamethasone to promote fetal pulmonary maturity is a separate issue. (See "Antenatal corticosteroid therapy for reduction of neonatal respiratory morbidity and mortality from preterm delivery", section on 'Betamethasone or dexamethasone?'.)
POSTPARTUM CARE AND COURSE
●Care – Patients who are critically ill or at substantial risk for developing serious complications can benefit from transfer to an intensive care setting, rather than a postpartum unit. Potential indications for intensive monitoring include threatened or actual liver rupture or fulminant liver failure, DIC, acute kidney injury, massive transfusion with concern about protecting the airway, transfusion-related acute lung injury, and cardiac ischemia or cardiomyopathy.
Magnesium sulfate is usually continued for 24 to 48 hours postpartum. (See "Preeclampsia: Intrapartum and postpartum management and long-term prognosis", section on 'Duration of therapy'.)
Supportive care may involve oxygenation and ventilation (ie, supplemental oxygen or mechanical ventilation), sedation, pain control, hemodynamic support (ie, vasopressors), monitoring, volume management (ie, intravenous fluids or diuretics), nutritional support, stress ulcer prophylaxis, and venous thromboembolism prophylaxis. (See "Critical illness during pregnancy and the peripartum period".)
●Resolution of laboratory results – Laboratory results may initially worsen in the 48 hours following birth (eg, platelet count usually decreases by 40 percent/day, hematocrit falls, and liver enzymes increase) [49], which is the reason that the American College of Obstetricians and Gynecologists recommends laboratory testing at least at 12 hour intervals in the postpartum period [22]. We stop checking laboratory values once they are clearly beginning to return to normal. Although liver enzymes return to normal or substantially decrease by the fourth postpartum day [42,43,49,50], in one report, total bilirubin levels were elevated in 20 percent of patients who had liver function tests checked 3 to 101 months after giving birth [51].
An upward trend in platelet count and a downward trend in lactate dehydrogenase (LDH) concentration are usually seen by the fourth postpartum day in the absence of complications. In a series of 158 patients with HELLP syndrome, platelet counts decreased until 24 to 48 hours after birth, while serum LDH concentration usually peaked at this time [49]. In all patients who recovered, a platelet count greater than 100,000 cells/microL was achieved by the sixth postpartum day or within 72 hours of the platelet nadir. Others have reported similar findings [50]. The platelet count rebound can overshoot; one group reported values of 413,000 to 871,000 cells/microL [52].
If the platelet count continues to fall and LDH continues to rise after the fourth postpartum day, then diagnoses other than HELLP syndrome (eg, primary thrombotic microangiopathy) should be considered [22]. However, recovery can be delayed in patients with particularly severe HELLP, such as those with disseminated intravascular coagulation (DIC), platelet count less than 20,000 cells/microL, renal dysfunction, or ascites [18,53]. These patients are at risk of developing pulmonary edema and acute kidney injury.
OUTCOME AND PROGNOSIS
Maternal outcome
Complications — The outcome for patients with HELLP is generally good; however, serious complications are relatively common. In the author's series of 437 patients with HELLP syndrome at a tertiary care facility, the following complications were observed [19]:
●Bleeding – 55 percent required transfusions with blood or blood products; 2 percent required laparotomies for major intraabdominal bleeding
●Disseminated intravascular coagulation (DIC) – 21 percent
●Placental abruption – 16 percent
●Acute kidney injury – 8 percent
●Pulmonary edema – 6 percent
●Subcapsular liver hematoma (or hepatic rupture) – 1 percent
●Retinal detachment – 1 percent
●Death – 1 percent
Many of these complications are interdependent (eg, abruption is a common obstetric etiology of DIC, which, in turn, may induce acute kidney injury, which may lead to pulmonary edema; massive bleeding from the liver, postpartum uterine atony, or lacerations could also lead to DIC).
Additional complications that have been reported in other series include adult respiratory distress syndrome, sepsis, stroke, cerebral hemorrhage and edema, and hepatic infarction (in patients with antiphospholipid syndrome) [6,54,55]. Wound complications secondary to bleeding and hematomas are common in patients with thrombocytopenia.
The risk of serious morbidity correlates with increasing severity of maternal symptoms and laboratory abnormalities [23,56]. In a report of four patients with aspartate aminotransferase levels >2000 IU/L and lactate dehydrogenase levels >3000 IU/L, all had disordered mental status, jaundice, intense hemolysis, and severe hypertension; one had multiorgan failure; and two died [56].
HELLP with or without acute kidney injury does not affect long-term renal function [57,58].
Recurrence in subsequent pregnancies — In a meta-analysis of individual patient data from 512 patients with HELLP who became pregnant again, 7 percent developed HELLP in a subsequent pregnancy [59]. In addition, 18 percent developed preeclampsia and 18 percent gestational hypertension.
In a subsequent Norwegian registry-based study of 577 patients with HELLP in their first pregnancy and then a second pregnancy, 24 percent developed hypertensive disorders of pregnancy that included either HELLP syndrome, preeclampsia, pregnancy-induced hypertension, or eclampsia in the second pregnancy compared with 3.6 percent of patients with no HELLP in their first pregnancy [60]. The study did not provide results for recurrent HELLP syndrome alone. The risk of recurrence of hypertensive disorders of pregnancy was higher in patients with preterm versus term HELLP in the first pregnancy (30.3 versus 16.5 percent).
Prevention — There is no evidence that any therapy prevents recurrent HELLP syndrome, but data are limited. The author considers HELLP syndrome a form of severe preeclampsia and prescribes low-dose aspirin during the second and third trimesters in future pregnancies to reduce the risk of preeclampsia. Evidence for use of low-dose aspirin for prevention of preeclampsia is discussed separately. (See "Preeclampsia: Prevention", section on 'Low-dose aspirin'.)
Fetal/neonatal outcome — Maternal laboratory parameters do not predict risk for fetal demise. The neonatal and long-term prognoses are most strongly associated with gestational age at birth and birth weight [61-69].
The overall perinatal mortality rate is 7 to 20 percent; complications of preterm birth, intrauterine growth restriction, and abruption are the leading causes of perinatal death [18,62].
Preterm birth is common (70 percent; with 15 percent of births before 27 weeks) [61]. Leukopenia, neutropenia, and thrombocytopenia may be observed in the neonate but appear to be related to intrauterine growth restriction, preterm birth, and maternal hypertension rather than HELLP [63]. Maternal HELLP does not affect fetal/neonatal liver function.
MANAGEMENT OF PATIENTS PRESENTING POSTPARTUM — All of the signs and symptoms of HELLP, including subcapsular hematoma and liver rupture, can initially appear in the postpartum period [70]. Management is similar to that of HELLP diagnosed before birth, except fetal status no longer needs to be considered.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hypertensive disorders of pregnancy".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topic (see "Patient education: HELLP syndrome (The Basics)" and "Patient education: High blood pressure and pregnancy (The Basics)")
SUMMARY AND RECOMMENDATIONS
●Prevalence – HELLP syndrome (hemolysis with a microangiopathic blood smear, elevated liver enzymes, and low platelet count) develops in 0.1 to 1 percent of pregnancies. (See 'Prevalence' above.)
●Clinical presentation – The most common clinical presentation is abdominal pain and tenderness in the midepigastrium, right upper quadrant, or below the sternum. Many patients also have nausea, vomiting, and malaise, which may be mistaken for a viral illness. Hypertension and proteinuria are present in approximately 85 percent of cases (table 2). Most cases of HELLP are diagnosed between 28 and 36 weeks of gestation, but symptoms may present up to 7 days postpartum. (See 'Patient presentation' above.)
●Diagnosis – The diagnosis of HELLP is based on the presence of all of the following criteria (Tennessee classification) (see 'Diagnosis' above):
•Hemolysis, established by at least two of the following:
-Peripheral smear with schistocytes and burr cells (picture 2)
-Serum bilirubin ≥1.2 mg/dL (20.52 micromol)
-Low serum haptoglobin or lactate dehydrogenase (LDH) ≥2 times the upper level of normal (based on laboratory-specific reference ranges)
-Severe anemia, unrelated to blood loss
•Elevated liver enzymes:
-Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≥2 times the upper level of normal (based on laboratory-specific reference ranges)
•Low platelets: <100,000 cells/microL.
●Differential diagnosis – The four major disorders in differential diagnosis are acute fatty liver of pregnancy, thrombotic thrombocytopenic purpura, pregnancy-related hemolytic-uremic syndrome, and systemic lupus erythematosus. All have features that overlap with HELLP (table 3A-B). (See 'Differential diagnosis' above.)
●Outcome/prognosis
•Maternal – The outcome for mothers with HELLP syndrome is generally good, but serious complications such as abruption, acute kidney injury, subcapsular liver hematoma or hepatic rupture, pulmonary edema, hemorrhage, retinal detachment, and death may occur. Maternal complications may be present on presentation or may develop because of delay in delivery due to diagnostic delay or waiting to complete a course of antenatal corticosteroids for fetal maturation. (See 'Maternal outcome' above.)
Future pregnancies are at increased risk of developing HELLP, preeclampsia, and gestational hypertension. (See 'Recurrence in subsequent pregnancies' above.)
•Pediatric – The short-term and long-term prognoses for the infant are primarily related to gestational age at delivery and birth weight: Preterm delivery and low birth weight are common. Maternal HELLP does not affect fetal/neonatal liver function. (See 'Fetal/neonatal outcome' above.)
●Management
•Initial management – The initial steps are to assess the mother, stabilize patients who are unstable, and assess gestational age and fetal status (nonstress test, ultrasound examination for biophysical profile and fetal presentation). Because of the potential for severe maternal complications, which can develop rapidly, patients with HELLP should be managed at a tertiary care center with appropriate levels of maternal and neonatal intensive care. Our general approach to management is illustrated in the algorithm (algorithm 1). (See 'Management of patients presenting before delivery' above.)
•Treatment of severe hypertension – Patients with severe hypertension should receive antihypertensive therapy (eg, intravenous labetalol (table 4)) promptly to reduce the risk of stroke. (See 'Patients requiring urgent assessment or intervention' above.)
•Treatment of hepatic bleeding – Although uncommon, severe right upper quadrant/epigastric pain may be due to hepatic bleeding, which may remain contained or rupture the liver capsule. The management of a hematoma is to support the patient with volume replacement and transfusion of blood and blood products, as needed. Prompt delivery is indicated once they are hemodynamically stable and severe anemia and coagulopathy, if present, have been corrected. A team experienced in liver trauma surgery should be consulted during maternal stabilization and prior to delivery. (See 'Patients requiring urgent assessment or intervention' above.)
•Magnesium sulfate – Magnesium sulfate is given intravenously to patients on the labor and delivery unit to prevent convulsions and for fetal/neonatal neuroprotection in pregnancies between 24 and 32 weeks of gestation with a live fetus. (See "Neuroprotective effects of in utero exposure to magnesium sulfate" and "Preeclampsia: Intrapartum and postpartum management and long-term prognosis", section on 'Regimen'.)
•Antenatal corticosteroids. – Antenatal corticosteroids to enhance fetal lung maturation are administered when the gestational age is above the lower limit of viability and <34 weeks of gestation. We recommend not administering dexamethasone for treatment of HELLP syndrome (Grade 1B). Dexamethasone does not accelerate resolution of laboratory abnormalities or reduce the risk of maternal complications. (See 'Is there a role for dexamethasone in treatment of HELLP?' above.)
●Timing of delivery
•Patients requiring urgent delivery – Patients with disseminated intravascular coagulation, pulmonary edema, or renal failure should be stabilized and delivered. (See 'Patients requiring urgent assessment or intervention' above.)
•For pregnancies ≥34 weeks of gestation in which maternal and fetal status are reassuring, we recommend delivery rather than expectant management (Grade 1C). In this population, the potential risks of preterm birth are outweighed by the risk of developing serious complication associated with HELLP syndrome. We also deliver pregnancies below the limit of viability because expectant management is associated with a high risk of developing maternal complications without significant improvement in perinatal prognosis. (See 'Our approach' above.)
•For pregnancies above the limit of viability and <34 weeks of gestation in which maternal and fetal status are reassuring, we suggest delivery after a course of betamethasone to accelerate fetal pulmonary maturity rather than expectant management or prompt delivery (Grade 2C). Although the laboratory abnormalities of HELLP syndrome will reverse in a subgroup of patients managed expectantly and serious maternal complications are uncommon with careful maternal monitoring, overall perinatal outcome is not improved with expectant management. (See 'Management of candidates for 48 hour delay before delivery' above.)
For pregnancies less than 30 to 32 weeks with an unfavorable cervix, we suggest cesarean birth (Grade 2C). These patients are likely to have a prolonged induction if vaginal birth is attempted. (See 'Choosing the route of birth' above.)
