The role of hepatic sinusoidal obstruction in the pathogenesis of the hepatic involvement in HELLP syndrome: Exploring the literature.

AIM: This study aims to determine, based on existing data, whether the mechanism resulting in liver dysfunction in HELLP syndrome resembles that in Sinusoidal Obstruction Syndrome (SOS). BACKGROUND: HELLP syndrome is a serious pregnancy disorder with high maternal and perinatal morbidity and mortality rates. Because of poor insight in its pathophysiology, particularly that of the liver involvement, clinical management is limited to symptomatic treatment, often followed by termination of pregnancy. SOS is a rare, potentially life-threatening complication of radio and/ or chemotherapy in the preparation of hematopoietic cell transplantation. The etiology of liver dysfunction in SOS is - unlike that in HELLP syndrome - better-understood and seems to be initiated by direct toxic damage and demise of endothelial cells, causing hepatic sinusoidal obstruction and ischemia. METHODS: We searched Pubmed, Embase and Cochrane for reports on the etiology of HELLP and SOS. This yielded 73 articles, with 14 additional reports from the references listed in these articles. RESULTS: The dysfunctional placenta in women developing HELLP initiates a cascade of events that eventually results in liver dysfunction. The placenta releases, besides anti-angiogenetic factors, also necrotic debris and cell-free DNA, a mixture that not only induces systemic endothelial dysfunction as in preeclampsia, but also a systemic inflammatory response. The latter aggravates the endothelio-toxic effects in the systemic cardiovascular bed, amplifying the already increased pro-thrombotic conditions. Particularly in microcirculations with extremely low shear forces, such as in the hepatic sinusoids, this will facilitate microthrombi formation and fibrin deposition eventually resulting in obstruction of the sinusoids similar as in SOS. The latter causes ischemic damage and progressive demise of hepatocytes. CONCLUSION: The available information supports the concept that the liver damage in HELLP and SOS results from sinusoidal ischemia, presumably resulting from partially overlapping pathophysiological mechanisms.

Early-Pregnancy Circulating Antioxidant Capacity and Hemodynamic Adaptation in Recurrent Placental Syndrome: An Exploratory Study.

BACKGROUND/AIMS: Placental syndromes (PS) refer to pregnancy complications that include gestational hypertension, (pre)eclampsia, HELLP syndrome, and/or placental insufficiency-induced fetal growth restriction. These disorders are characterized by increased oxidative stress. This study aims to test the hypothesis that the abnormal hemodynamic adaptation to pregnancy, typical for early PS pregnancy, is accompanied by abnormal maternal levels of antioxidants relative to those in normal pregnancy. METHODS: Before, and at 12, 16, and 20 weeks pregnancy, we measured trolox equivalent antioxidant capacity (TEAC), uric acid (UA), and TEACC (TEAC corrected for UA) in maternal serum of former PS patients, who either developed recurrent PS (rPS; n = 16) or had a normal next pregnancy (non-rPS; n = 23). Concomitantly, we also measured various hemodynamic variables. RESULTS: rPS differed from non-rPS by higher TEACC levels before pregnancy (178 vs. 152 µM; p = 0.02) and at 20 weeks pregnancy (180 vs. 160 µM; p = 0.04). Only non-rPS responded to pregnancy by significant rises in hemodynamic measures. CONCLUSION: These data indicate that rPS pregnancies are preceded by an increase in antioxidant capacity, presumably induced by subclinical vascular injury and low-grade chronic inflammation.

Reliability and Validity of a Smartphone-Paired Pulse Oximeter for Screening of Critical Congenital Heart Defects in Newborns.

BACKGROUND: Barriers to widespread implementation of pulse oximetry screening of critical congenital heart defects (CCHD) in newborns include increasing trends of out-of-hospital births and cost of equipment. In recent years, smartphone-compatible pulse oximeters have appeared on the market, but the validity of such devices in the setting of CCHD screening has not been evaluated. OBJECTIVES: To compare the performance in CCHD screening of a smartphone-paired pulse oximeter (Masimo iSpO2-Rx™) and a hospital-grade pulse oximeter (Masimo Radical-7™). METHODS: Preductal (right hand) and postductal (either foot) saturations were determined in a population of 201 term newborns by 2 independent teams, one using the Radical-7 and the other using the iSpO2-Rx. Bland-Altman analysis was applied to calculate mean bias and 95% limits of agreement between the 2 pulse oximeters. RESULTS: For the preductal oxygen saturation, the mean bias (Radical-7 minus iSpO2-Rx) was -0.08 (SD 1.76) and the lower and upper limits of agreement were -3.52 and 3.36, respectively. For the postductal oxygen saturation, the mean bias was -0.11 (SD 1.68) and the lower and upper limits of agreement were -3.49 and 3.18, respectively. In addition, the iSpO2-Rx provided reliable measurements of saturations below 95% in a group of 12 infants admitted to the neonatal intensive care unit. CONCLUSIONS: Our data suggest that CCHD screening with the Masimo iSpO2-Rx is feasible and accurate. The use of reliable smartphone-paired pulse oximeters may contribute to the extension of CCHD screening to home births and low resource settings.

Circulating Fibronectin and Plasminogen Activator Inhibitor-2 Levels as Possible Predictors of Recurrent Placental Syndrome: An Exploratory Study.

BACKGROUND/AIM: Placental syndromes (PS) are characterized by endothelial dysfunction complicating placental dysfunction. Possible markers for endothelial dysfunction and amount of trophoblast are fibronectin and plasminogen activator inhibitor-2 (PAI-2), respectively. We aimed (1) to determine whether in women with recurrent PS (rPS), this complication is preceded by deviating fibronectin- and PAI-2-levels, and (2) whether this is dependent on pre-pregnant plasma volume (PV). METHODS: In 36 former patients, we determined fibronectin- and PAI-2-levels in blood-samples collected preconceptionally and at 12-16 weeks in their next pregnancy. Differences were analyzed between pregnancies with rPS (n = 12) and without rPS (non-rPS, n = 24) using linear mixed models, with subanalyses based on pre-pregnant normal or subnormal PV. RESULTS: We observed higher fibronectin-levels at 12-16 weeks (p < 0.05 and p < 0.01, respectively) and lower PAI-2-levels at 16 weeks (p < 0.01) in the rPS subgroup, the intergroup differences being larger in women with subnormal PV. CONCLUSION: We showed that former PS patients who developed rPS have raised fibronectin- and reduced PAI-2-levels already in early/mid pregnancy. These deviations are even more prominent in women with subnormal pre-pregnant PV, supporting development of a 2-step screening program for former patients to identify the high-risk subgroup of women who may benefit from closer surveillance.

[Thromboprophylaxis in pregnant women should be individually tailored]. / Tromboprofylaxe bij zwangeren is maatwerk.

Roeters van Lennep et al. recently evaluated efficacy and safety of thromboprophylaxis with low dose low-molecular-weight heparin (LMWH) in women with intermediate and high risk of pregnancy-related venous thromboembolism (VTE). Lessons to be drawn from this study are that the risk of VTE should be estimated preconceptionally, that the current LMWH prophylaxis is sufficient during pregnancy and the post-partum period for women with an intermediate risk of VTE, that from a haemostatic point of view the post-partum period does not end at 6 weeks but at 3 months, and that the prophylactic LMWH dosage is insufficient in 1 out of 20 women with a high risk of VTE.