Could Low Molecular Weight Heparin Prevent Preeclampsia?
سه شنبه 1395/9/23








Pregnant women at high risk for preeclampsia who were given low molecular weight heparin (LWMH) showed improvement in endothelial function, thus apparently reducing their cardiovascular disease risk, researchers found.

In vitro experiments also showed that, when LMWH was added to the serum of high-risk women, angiogenic activity was increased to the point where it became similar to that seen in untreated serum from low-risk women, the authors wrote in Hypertension.

"We demonstrate for the first time that [low molecular weight heparin] acutely improves endothelium-dependent vascular function in pregnant women at high risk of [preeclampsia]," they wrote. "These results illustrate a potential mechanisms whereby LMWH could exert a beneficial effect on maternal endothelial function, as previously demonstrated in patients with [coronary artery disease]."


The authors noted that previous research had found that administering heparin throughout pregnancy prevented the rise of systolic and diastolic blood pressure and resistance of uterine arteries in pregnant women at high risk of preeclampsia.

This small trial examined data from 20 pregnant women considered at low risk for preeclampsia and 25 pregnant women at high risk, evaluated at 22-26 weeks gestation. The women were then randomized to receive either LMWH or saline. High-risk women unsurprisingly had higher levels of systolic, diastolic and mean arterial blood pressure and heart rate, though the authors noted that no women were clinically hypertensive. Their baseline radial artery flow-mediated dilation was also significantly lower than low-risk women (6.5 ± 0.9% versus 9.7 ± 1.0%, P=0.03).

High-risk women had significantly lower levels of angiogenic proteins, with significantly lower levels of plasma and urine placental growth factor.

But compared to high-risk women randomized to placebo, those randomized to LMWH showed significant increases in plasma levels of placenta growth factor (PIGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and myeloperoxidase (MPO).

In the in vitro experiments, serum from the high-risk group "significantly arrested" angiogenesis in human umbilical vein endothelial cells, which was abolished when LMWH was added to the high-risk group serum. Neither effect was seen with serum from low-risk patients.

The authors cited their findings as evidence that an "adequately powered" trial to determine the effectiveness of low-molecular weigh heparin in preventing early onset preeclampsia in high-risk women, noting that it has demonstrated a good safety profile with no obvious maternal or fetal side effects.

"In this capacity, LWMH could potentially avert serious maternal vascular dysfunction during pregnancy, leading to improved clinical outcomes," they concluded.



sorce: Cancer network

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