733 The association of endoplasmic reticulum (ER) stress with labor and evidence of placental vascular malperfusion

Abstract

To determine if the degree of ER stress, as measured by staining intensity via glucose regulatory protein 78(GRP78), correlates with clinical outcomes of pregnancy; if there is a unique pattern of maternal (MVM) and fetal vascular malperfusion (FVM) lesions and if there is a correlation with duration of labor Women planning a pregnancy, were recruited between 2010-2014 (IRB approved). Chronic medical illnesses were excluded except chronic hypertension. Clinical or histopathologic evidence of chorioamnionitis(n=12) and missing data(n=5) were excluded resulting in 51 placentas(hypertensive n=14, normotensive n=37).Immunofluorescence was performed using GRP78 marker(CST ®) and staining was analyzed in the trophoblastic cytoplasm. Placentas were histologically classified and graded for individual MVM and FVM lesions, by a board-certified perinatal pathologist (blinded to clinical outcome), using the Amsterdam Placental Workshop Consensus Statement. Spearman’s correlation coefficients were used between GRP78 staining and labor duration, gestational age, birth weight, placental weight, MVM and FVM lesions. T-tests were used for dichotomous variables. Data is presented as mean ± SD with p<0.05 accepted for statistical significance. A positive correlation was noted between duration of second stage of labor and GRP78 staining(p=0.03) independent of hypertensive outcome. No significant associations were noted of GRP78 with total duration of labor, length of ruptured membranes, term or preterm preeclampsia or gestational hypertension. A statistically significant increase in GRP78 staining was noted with delayed villous maturation (1226+/-774 without vs w=1718+/-780 with; p=0.038).However, there were no associations between GRP78 staining and other individual MVM or FVM lesions, or their grades. The presence of ER stress in normal labor may confound the ability to elucidate its role in hypertensive disorders of pregnancy. The association between GRP78 and DVM is unexpected, since it is associated with macrosomia and gestational diabetes. Larger studies are needed to investigate this.View Large Image Figure ViewerDownload Hi-res image Download (PPT)