Comparison of clinical features and pregnancy outcomes in early- and late-onset preeclampsia with HELLP syndrome: a 10-year retrospective study from a tertiary hospital and referral center in China.

BACKGROUND: Early-onset preeclampsia (EO-PE) and late-onset preeclampsia (LO-PE) are different subtypes of preeclampsia. We conducted this study to analyze the similarities and differences in the clinical features and pregnancy outcomes in EO- and LO-PE with HELLP syndrome. METHODS: This was a retrospective study in a tertiary hospital. Eighty-three parturients with HELLP syndrome were allocated into two groups based on the timing of preeclampsia onset: EO-PE with HELLP (n = 47) and LO-PE with HELLP (n = 36). RESULTS: In total, 31.9% and 63.9% of women in the EO-PE with HELLP and LO-PE with HELLP groups, respectively, were asymptomatic at diagnosis (P = 0.004, OR = 0.265 (0.106-0.662)). Headache or visual symptoms were more frequent in the EO-PE group than in the LO-PE group (48.9% vs. 25%, P = 0.026, OR = 0.348 (0.135-0.896)). Women in the EO-PE with HELLP group had higher SBP and DBP than those in the LO-PE with HELLP group. Laboratory tests, including platelets, liver function, and hemolysis, which are the main indicators for the diagnosis of HELLP syndrome, showed almost no significant differences between the two groups, with kidney function being the only difference observed. Women in the EO-PE with HELLP group had higher Scr than those in the LO-PE with HELLP group. The degree of proteinuria was higher in the EO-PE group than in the LO-PE with HELLP group. The incidence of severe maternal complications was significantly higher in the EO-PE group than in the LO-PE with HELLP group (25.5% vs. 5.6%, P = 0.016, OR = 0.172 (0.036-0.824)). In total, 57.4% and 8.3% of neonates in the EO-PE and LO-PE with HELLP groups were admitted to the NICU, and the difference was statistically significant, even after adjustment for the delivery week (P = 0.009, OR = 0.830 (0.729-0.944)). Postpartum HELLP syndrome was more common in the LO-PE group than in the EO-PE group (30.6% vs. 4.3%, P = 0.001, OR = 9.9 (2.031-48.256)). CONCLUSIONS: Compared with LO-PE with HELLP patients, EO-PE with HELLP patients have more obvious kidney damage, higher blood pressure and a higher risk of adverse maternal and neonatal outcomes. Patients with LO-PE need to be alerted to the occurrence of HELLP syndrome after delivery.

Recurrent Placental Transcriptional Profile With a Different Histological and Clinical Presentation: A Case Report.

Statistically, patients with severe pregnancy complications are at risk of recurrent complications, but it is less understood if patients present with similar or different placental pathologies in subsequent pregnancies. In this case report, we describe 2 consecutive adverse pregnancies in the same woman 4 years apart. The first pregnancy was diagnosed as early-onset preeclampsia and hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, with placental maternal vascular malperfusion features, such as syncytial knots and accelerated villous maturity. In contrast, the second pregnancy was associated with normotensive fetal growth restriction and placental "immunological" lesions, such as massive perivillous fibrin deposition and chronic intervillositis. However, based on the expression of FLT1, LIMCH1, and TAP1 by quantitative polymerase chain reaction, the placentas from both pregnancies were found to exhibit an "immunological" transcriptional signature. This suggests that this small panel of gene expression markers may be able to predict the future reoccurrence of an immunological placental pathology despite no histological evidence within the first pregnancy. These results call for more studies looking at paired pregnancies of individuals with recurrent obstetric complications and confirm the importance of assessing matched transcriptional and histopathological placental information.

Color vision abnormality as the sole manifestation of posterior reversible encephalopathy due to post-partum HELLP syndrome.

Posterior reversible encephalopathy syndrome (PRES) is associated with several symptoms; of those, visual acuity loss, light oversensitivity (photophobia), and light flashes (photopsia) are known as PRES-related eye symptoms. We report a post-partum woman with PRES associated with hemolysis, elevated liver enzymes, and low platelets syndrome (HELLP), in whom color vision abnormality (achromatopsia) was the sole manifestation. Cesarean section was performed at 28 weeks due to headache, epigastralgia, and severe hypertension. HELLP became evident after delivery. On post-partum day 1, she complained of achromatopsia, stating: "all things look brownish-gray". Ophthalmologic examination was normal, but brain magnetic resonance imaging showed occipital lobe lesions, indicative of PRES, and, interestingly, also color vision center (area V4) lesions, suggesting that the achromatopsia had been caused by brain damage. It may be prudent to question HELLP patients concerning achromatopsia.

Placental expression of vimentin, desmin and ultrastructural changes in the villi in patients with HELLP syndrome.

OBJECTIVES: To examine placental expression of vimentin and desmin in relation to ultrastructural changes within the placental villi in cases of HELLP syndrome. STUDY DESIGN: Formaldehyde-fixed and paraffin-embedded specimens of 15 healthy pregnant and 13 Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome, placentas were used for Harris hematoxylin staining, vimentin and desmin immunohistochemistry, and transmission electron microscopy (TEM). RESULTS: Increased of fibrinoid necrosis in vascular wall and the periphery of villi were observed in sections of the placentas with HELLP syndrome. Increased expression of vimentin in the intravillous area and increased expression of desmin on blood vessel wall, were seen in placentas of patients with HELLP syndrome when compared to placentas of healthy pregnant. CONCLUSIONS: Augmentation of intermediate filaments, desmin, vimentin may disturb normal movements of endothelial cells, and may display placental dysfunction that is unable to compensate the endothelial instability and the related hypertension in HELLP syndrome. Further studies are needed to get more definit results and also to compare HELLP syndrome with preeclampsia.

Spectrum of neurological complications in HELLP syndrome.

BACKGROUND: Hemolysis (H), elevated liver enzymes (EL), and low platelets (LP), HELLP syndrome is the extended spectrum of severe preeclampsia and is associated with high mortality. A large proportion of mortality can be attributed to catastrophic central nervous system events. AIMS: The purpose of this study was to access the clinical manifestations, radiological abnormalities and outcome in patients of HELLP syndrome with neurological manifestations. SETTING: Obstetric unit and neurology intensive critical unit (ICU) of an academic medical center. STUDY DESIGN: Retrospective study. SUBJECTS AND METHODS: Case records of all obstetrical patients who were admitted between January 2012 and December 2012 were screened and data was collected from those patients who were diagnosed with HELLP syndrome with neurological complications. It was entered into a structured performa and analyzed using percentages . RESULTS: During the study period; 1,166 deliveries were conducted, 108 patients had pregnancy-induced hypertension (PIH); and of the 12 patients with HELLP, eight (66%) patients had neurological complications. The presenting neurological features were seizures (four), focal neurological deficits (two), and encephalopathy (two). Of the eight patients, in six patients neuroimaging showed features of posterior reversible encephalopathy syndrome (PRES), three of them had associated hemorrhage, and two patients had isolated intracranial hemorrhage. All except two were discharged home. CONCLUSIONS: Neurological complications are not uncommon in patients with HELLP syndrome and a high index of suspicion is essential. Aggressive multidisciplinary approach is the key to reduce the morbidity and mortality.

Role of SOX9 and Hif-1α expression in placentas of patients with HELLP.

PURPOSE: In this study, we investigated the immunohistochemical staining of SRY-box transcription factor 9 (SOX9) and Hif-1α expression in placentas of pregnant woman with hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome. METHODS: Placentas of 20 normotensive and 20 women with HELLP syndrome were processed for routine histological tissue processing. The biochemical and clinical parameters of patients were recorded. Placentas were stained with hematoxylin-eosin and SOX9 and Hif-1α immunostaining. RESULTS: Normotensive placentas showed normal histology of placenta, however placentas of HELLP syndrome showed intense thrombosis, thinning of the villi membrane and vascular dilatation. In placentas of normotensive patients, SOX9 reaction was immunohistochemically negative, however placentas of HELLP group showed SOX9 expression in decidual cells, and syncytial regions of floating villi and inflammatory cells. In placentas of normotensive patients, Hif-1α reaction was mainly negative in vessels and connective tissue cells. Placentas of HELLP group showed increased Hif-1α expression in decidual cell and especially inflammatory cells in the maternal region. CONCLUSIONS: Hif-1α and SOX9 proteins can be used as a marker to show severity of preeclampsia and regulation of cell proliferation and angiogenesis during placental development.

Role of cited-1 and caspase-6 expression in HELLP syndrome.

OBJECTIVE: In this study, we investigated the immunohistochemical staining of cited-1 and caspase-6 expression in the placentas of pregnant women with HELLP syndrome. PATIENTS AND METHODS: Placentas of 20 normotensive patients and 20 women with HELLP syndrome were processed for routine histological tissue processing. The biochemical and clinical parameters of patients were recorded. Placentas were stained with hematoxylin-eosin and cited-1 and caspase-6 immunostaining. RESULTS: Placentas of normotensive patients showed normal histology. Placentas of women with HELLP syndrome showed degenerated cells, hyalinization and vacuolization. Cited-1 expression was negative in normotensive group; however, it was increased in HELLP group, especially in decidual cells, endothelial cells and other placental cells. Caspase-6 expression was negative in placental structures of normotensive groups. However, it was intense in decidual cells, vacuolar and hyalinized areas, inflammatory cells and connective tissue cells in HELLP group. CONCLUSIONS: Cited-1 and caspase-6 are a marker in determining the severity of HELLP syndrome.

Angiotensin-1 and vimentin expression and ultrastructural examination in severe preeclampsia complicated by HELLP syndrome changes in the structure of the umbilical cord.

OBJECTIVE: The purpose of this study was to examine the histopathologic, ultrastructural and immunohistochemical changes in the umbilical cord in women diagnosed with HELLP syndrome. MATERIALS AND METHODS: Postpartum umbilical cords of 40 patients at the 35-38th week of pregnancy were included. 20 severe preeclamptic (HELLP) and 20 normal umbilical cords were used. After the follow-up of tissue parts of 10% formaldehyde solution for histopathology and immunohistochemistry, histopathological and angiopoietin-1 and vimentin antibodies were examined as immunohistochemical after routine paraffin follow-up. For electron microscope analysis, umbilical cord samples were taken into 2.5% glutaral aldehyde solution. RESULTS: In the statistical comparison, mean difference in increased diameter and additional anomaly on the ultrasound of preeclamptic patients was statistically different compared to control patients. In the HELLP group, hyperplasia and degenerative changes, pyknosis of the endothelial cell nuclei of the vessels and apoptotic changes in some regions were observed. Immunohistochemical analysis showed that endothelial cells, basal membrane and fibroblast cells in the HELLP group expressed high levels of vimentin. Angiotensin-1 expression was increased in amniotic epithelial cells, endothelial cells and some pericyte cells. CONCLUSIONS: As a result, it was observed that the signaling that started with trophoblastic invasion with the effect of hypoxia in severe preeclampsia and continued with dysfunction in endothelial cells was parallel to the increase in angiotensin and vimentin receptors. It is thought that the ultrastructural change in endothelial cells may cause disruption of the collagenized structure in Wharton gel, which supports this, and may cause adverse effects in fetal development and nutrition.

Regulation of the human endogenous retroviral Syncytin-1 and cell-cell fusion by the nuclear hormone receptors PPARγ/RXRα in placentogenesis.

Cytotrophoblast (CT) cell fusion into a syncytiotrophoblast is obligatory for placentation and mediated by the human endogenous retrovirus (HERV)-W envelope gene Syncytin-1. Abnormal placentation is associated with preeclampsia (PE), HELLP and intrauterine growth restriction (IUGR). In placentogenesis, the MAP-kinase p38α regulates PPARγ/RXRα signaling and target genes, like leptin, resistin, ABCG2, and hCG. The aim of this study was to analyze PPARγ/RXRα signaling and target gene regulation using primary CT cultures, the trophoblastic cell line BeWo and placental tissues from patients with normal and abnormal placentation. CT from four different human control placentae and BeWo cells demonstrated that Syncytin-1, other signaling members and CT cell fusions were regulated with PPARγ/RXRα activators troglitazone and 9-cis retinoic acid, via protein kinase A and p38α inhibition. Significant discordant regulations between CTs and BeWo were found. Two PPARγ/RXRα-response-elements from upstream regulatory elements and the 5'LTR of HERV-W were confirmed with DNA-protein binding assays using nuclear extracts and recombinant PPARγ/RXRα proteins. These promoter elements were validated with luciferase assays in the presence of PPARγ/RXRα modulators. Furthermore, troglitazone or 9-cis retinoic acid treatment of siRNA-PPARγ and siRNA-RXRα transfected BeWo cells proved the requirement of these proteins for Syncytin-1 regulation. Thirty primary abnormal placentae from PE, HELLP and IUGR patients compared to 10 controls showed significant deregulation of leptin RNA and protein, p38α, phospho-p38α, PPARγ, ABCG2, INSL4 and Syncytin-1. Our study characterized PPARγ/RXRα signaling in human CT and cell fusions identifying Syncytin-1 as a new target gene. Based on these results, a disturbed PPARγ/RXRα pathway could contribute to pathological human pregnancies.

Long-term cerebral imaging after pre-eclampsia.

OBJECTIVE: Formerly eclamptic women demonstrate cerebral white matter lesions (WMLs) several years following the index pregnancy. The pathophysiology is unclear and may be related to the predisposition for cerebrovascular/cardiovascular disease in such women and/or the occurrence of posterior reversible encephalopathy syndrome whilst pregnant. The aim of this study was to assess the presence and severity of WMLs and their relationship with the severity of the neurological symptoms during the index pregnancy and several current cardiovascular risk factors in formerly pre-eclamptic women. DESIGN: This was a retrospective cohort study. SETTING: The Neuroimaging Centre at the School for Behavioural and Cognitive Neurosciences, Groningen, the Netherlands. POPULATION: Seventy-three formerly pre-eclamptic women were matched for age (37 ± 6 years) and elapsed time since index pregnancy (5.1 ± 3.7 years) with parous control women. METHODS: Cerebral magnetic resonance imaging scans were performed on cases and controls. Scans were rated by a neuroradiologist blind to the patient category. MAIN OUTCOME MEASURES: The presence and severity of cerebral WMLs. RESULTS: Formerly pre-eclamptic women had WMLs significantly more often (37%) and more severely (mean, 0.11; median, 0.00; range, 0-2.34 ml) than controls (21%, P = 0.04; mean, 0.015; median, 0.00; range, 0-0.13 ml; P = 0.02). Current hypertension and a history of early-onset pre-eclampsia (<37 weeks) were independently associated with the presence of WMLs (ß = 1.34, P = 0.02 and ß = 1.73, P = 0.01, respectively). CONCLUSIONS: Our findings indicate that pre-eclampsia might be a risk marker for early cerebrovascular damage. The predisposition of formerly pre-eclamptic women to later cardiovascular and cerebrovascular disease may be an important factor for the development of cerebral WMLs. Whether a history of posterior reversible encephalopathy syndrome may be an additive risk factor for the development of these lesions remains unknown.

Comparison of placental pathology between severe preeclampsia and HELLP syndrome.

OBJECTIVE: This study was performed to evaluate and compare the placental pathology in patients with severe pre-eclampsia (PE) and HELLP syndrome. Moreover, neonatal birth weight was compared between the two groups. MATERIALS AND METHODS: This cross-sectional prospective study was conducted in Alzahra and Beheshti Hospitals (Isfahan, Iran) between 2007 and 2009. Placentas from 32 patients having severe pre-eclampsia without HELLP (referred to as preeclampsia group) and 25 patients having severe preeclampsia with HELLP syndrome (referred to as HELLP group) were evaluated. The studied parameters included placental weight, chorioamnionitis (either acute or chronic), retroplacental hematoma, placental infarction, intervillous thrombosis, and decidual arteriopathy. Birth weight adjusted for gestational age was also compared between the two groups. RESULTS: We found statistically more significant frequency of retroplacental hematoma in the PE group compared to the HELLP group (P value 0.00). Despite the relatively high frequency of accelerated villous maturation and decidual arteriopathy in both groups, the difference between the two groups regarding these two parameters was not statistically significant. Other placental features did not show any significant difference between the two groups either. The frequency of small for gestational age births showed no statistically significant difference between the two groups. CONCLUSION: Retroplacental hematoma was the only placental pathology that showed statistically significant different frequencies between the two groups. Although this may suggest different underlying pathogenetic mechanisms in these two conditions, further studies are needed to confirm this hypothesis.

Placental protein 13 (PP13/galectin-13) undergoes lipid raft-associated subcellular redistribution in the syncytiotrophoblast in preterm preeclampsia and HELLP syndrome.

OBJECTIVE: To investigate placental protein 13 (PP13) localization in relation to cytoskeleton and lipid rafts in preeclampsia and HELLP syndrome. STUDY DESIGN: Placental cryosections from patients with preeclampsia and HELLP, and controls were stained for PP13, actin, PLAP (lipid raft marker), and CD71 (nonraft marker). BeWo cells exposed to stress conditions were stained for PP13 and actin. Protein localizations were investigated by confocal microscopy, PP13 concentrations by ELISA. RESULTS: PP13-actin colocalization was increased in syncytiotrophoblast juxtamembrane regions in term/preterm preeclampsia and HELLP. PP13-CD71 colocalization was decreased and PP13-PLAP proximity was increased in preterm but not term preeclampsia and HELLP. PP13-release from BeWo cells was inhibited by cytoskeleton disruption, and augmented by Ca2+-influx and ischemic stress. CONCLUSION: The actin cytoskeleton, probably in connection with lipid rafts, controls trophoblastic "nonclassical" PP13 export. PP13 is released from the syncytiotrophoblast in preterm preeclampsia and HELLP, mimicked in BeWo cells by ischemic stress, suggesting PP13 is a placental alarmin.

Apoptosis, proliferation and Fas ligand expression in placental trophoblast from pregnancies complicated by HELLP syndrome or pre-eclampsia.

OBJECTIVE: To investigate apoptosis, proliferation and Fas ligand expression of placental trophoblast in the hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome and in pre-eclampsia (PE), and to compare this with normal pregnancies. DESIGN: Prospective study. SETTING: University hospital in Croatia. SAMPLE: Placentae from women with HELLP syndrome (n=10), PE (n=10) and normal pregnancies (n=10). METHODS: The HELLP syndrome was diagnosed with platelets <100×10(9) /L, aspartate aminotransferase (AST) and alanine transaminase (ALT) >70 U/L and lactic acid dehydrogenase (LDH) > 600 U/L. Pre-eclampsia was diagnosed at blood pressure >140/90 mmHg, with proteinuria >300 mg/L/24 hours. For detection of apoptosis and proliferation in villous trophoblast, antibodies M30 and Ki-67 were used. Expression of Fas ligand was assessed using immunohistochemistry and the semiquantitative HSCORE method. MAIN OUTCOME MEASURES: Apoptosis, proliferation and Fas ligand expression in villous trophoblast. RESULTS: Apoptosis, proliferation and Fas ligand expression were higher in villous trophoblast in HELLP syndrome than in the PE group (p=0.015, p=0.018 and p=0.002, respectively) and the control group (p=0.000, p=0.012 and p=0.049, respectively). Placentae from the PE group had higher levels of apoptosis (p=0.019), lower Fas ligand expression (p=0.029) and no difference in proliferation (p=0.887) compared with the control group. CONCLUSIONS: There is an increase in apoptosis, proliferation and Fas ligand expression in placentae from women with HELLP syndrome compared with placentae from PE and normal pregnancies. Our findings indicate the possibility of differential mechanisms behind HELLP syndrome and PE.

Identification of Differential Expression Cytokines in Hemolysis, Elevated Liver Enzymes, and Low Platelet Syndrome by Proteome Microarray Analysis and Further Verification.

To screen the differential expression cytokines (DECs) in hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome, establish its differential cytokines spectra, and provide the clues for its diagnosis and pathogenic mechanism researches. Sera from four HELLP syndrome patients and four healthy controls were detected by proteome microarray. Then the analysis of Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) network were performed and possible hub proteins were selected out, further verified by Enzyme Linked Immunosorbent Assay (ELISA) in sera from 21 HELLP syndrome patients and 21 healthy controls. Thirty DECs were defined according to P-value and fold change between HELLP group and control group. GO enrichment analysis showed that DECs were mainly involved in the regulation of inflammatory response and have relationship to growth factor binding, transmembrane receptor protein kinase, and cytokine receptor activity. Seven possible hub proteins were defined by PPI analysis, including IGFBP-3/Follistatin-like 1/FLRG/Fetuin A and MMP-13/Thrombospondin-5/Aggrecan. ELISA showed higher serum levels of Fetuin A/IGFBP-3/FLGR/MMP-13/Thrombospondin-5 in HELLP group than those in controls, while the levels of Follistatin-like 1 and Aggrecan were lower in HELLP patients (all P < 0.05 or <0.01).The serological DECs spectra of HELLP syndrome was established and seven possible hub proteins that may be more closely related to the disease have been verified, providing new clues for its pathogenesis, diagnosis, and clinical treatment.

Vascularization in first-trimester chorionic villi in complicated and uncomplicated pregnancies.

OBJECTIVE: The purpose of this study was to investigate possible altered chorionic vascularization patterns that are seen already in the first trimester of pregnancies that are complicated by hypertensive disorders or intrauterine growth restriction (IUGR) in the third trimester of pregnancy. STUDY DESIGN: After chorionic villous sampling, surplus of villi were stored, and a selection was made of pregnancies that were complicated further by hypertensive disorders (n = 26), normotensive IUGR (n = 13), and matched control subjects (n = 60). Vascular parameters of these villi were analyzed with a video-image-analysis system. RESULTS: In pregnancies that are complicated by early-onset hypertensive disorders and IUGR, the mean distance of the peripheral vessels to the intervillous space and the total of the distances (central and peripheral) are significantly smaller, compared with control subjects (9.3% and 13.8% for hypertensive disorders and 12.2% and 16.1% for IUGR, respectively). CONCLUSION: Differences in vascularization patterns in the placenta already in the first trimester of pregnancies that are complicated later by hypertensive disorders or IUGR confirm the hypothesis of early changes by means of more vessels and more peripheral vessels that are located in chorionic villi.

Severe early onset hemolysis, elevated liver enzyme, and low platelet-syndrome in 2 subsequent pregnancies: case report and review of the literature.

BACKGROUND: Pregnancies after a previous pregnancy complicated by hemolysis, elevated liver enzyme, and low platelet (HELLP) syndrome carry an increased risk of HELLP-syndrome. CASE REPORT: We report on a 35-year-old patient with both HELLP-syndrome and fatal neonatal outcome in two subsequent pregnancies with delivery by cesarean section in the 26th and 27th gestational weeks, respectively. The children were immediately admitted to the neonatal intensive care unit but died in their postpartum period. Before the second pregnancy testing for antiphospholipid-syndrome revealed normal results. CONCLUSION: In general, pregnancies after HELLP-syndrome carry increased risks for pregnancy-related complications. Evaluation of the immunologic status and application of immune-globulins could be diagnostic and therapeutic options in our case. Further research is recommended to evaluate the mechanisms of recurrence of HELLP-syndrome.

[Clinicopathologic characteristics of HELLP-syndrome].

HELLP-syndrome is one of the most severe variants of liver failure in pregnancy. The incidence among pregnant patients is 0.5-0.9%, and in presence of severe preeclampsia and eclampsy the incidence is 10-20%. Pathogenesis of HELLP-syndrome has common features with pathogenesis of preeclampsia, DIC-syndrome and fatty hepatosis of pregnant, this is confirmed by pathomorphological changes of liver in women with HELLP-syndrome. Efficacy of conservative therapy (corticosteroids, magnesium sulphate, hypotensive therapy, hepatoprotectors) and disintoxication methods (plasmapheresis, MARS-therapy) is not evident. Difficulties of timely diagnosing, symptomatic nature of treatment, severity of complications lead to high rates of maternal (up to 25%) and perinatal (up to 34%) mortality. The only radical and efficient method of HELLP-syndrome treatment available is a timely delivery. That's why the revelation and consideration of the slightest clinical and laboratorial manifestations is very important in pregnancy.

Clinical characteristics and pregnancy outcomes of atypical hemolysis, elevated liver enzymes, and low platelets syndrome: A case series.

RATIONALE: Hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome is a serious and rare disease, which is secondary to preeclampsia in most cases. Hypertension is usually considered as a premonitory symptom of HELLP syndrome. In some patients with HELLP syndrome; however, they develop hypertension very late, even after liver enzymes are elevated or platelet count is decreased. This condition is known as atypical HELLP syndrome. PATIENT CONCERNS: We screened and identified 4 cases of atypical HELLP syndrome in our hospital database from January 2007 to December 2018. All patients had a history of nonspecific symptoms for a few days before hospital admission, such as dizziness, nausea, and vomiting. They developed hypertension after abnormalities were noted in liver enzymes and platelet count. DIAGNOSES: They were diagnosed with atypical HELLP syndrome. INTERVENTIONS: These patients received same treatments as those with HELLP syndrome. Two patients took oral antihypertensive treatment to normalize the blood pressure. OUTCOMES: In our patients, both mothers and neonates had favorable outcomes. In follow-ups, they reported no incidences of high blood pressure after recovery from atypical HELLP syndrome. LESSONS: These cases provided additional clinical evidences of atypical HELLP syndrome. The incidence of atypical HELLP syndrome is extremely low. Hypertension is not essential for the diagnosis of HELLP syndrome, and can even appear after the onset of laboratory abnormalities. Advanced age, multiple pregnancies, hepatitis B virus infection, and obesity may be potential risk factors for atypical HELLP syndrome. Blood pressure should be monitored closely after delivery.