Prediction of placental inflammation In cases of preterm premature rupture of membranes: the role of antepartum fetal surveillance modalities

ABSTRACT

To assess the values of various modalities of fetal surveillance namely the nonstress test [NST]. modified fetal biophysical profile [FBP] and umbilical artery Doppler velocimetry study [S/D ratio] as predictors of placental inflammation in cases of preterm premature rupture of membranes [PROM]. Forty-three pregnant women with singleton fetuses between 27 and 34 weeks gestation and with preterm PROM were included in the study. AU cases were subjected to daily NST, modified FEP and umbilical artery S/D ratios till delivery was indicated for completion of 34 weeks, start of onset of labor or evidence of fetal compromise. After delivery, the placentas were send for histopathologic evaluation and were classified into two groups according to absence [group I] or presence [group II] of placental inflammation. The last NST, modified FBP and longitudinal trends of umbilical artery S/D ratios In the last 3 days before, delivery were correlated to placental histopathologic findings. There was no statistically significant difference between both groups regarding the incidence of reactive or non-reactive NST [P-NSL A statistically significant higher incidence of modified FBP sensitivity, specificity, positive and negative predictive values and overall accuracy of these modalities were 64.3%, 65.5%, 47.4%, 79.2% and 65.1% for NST, 71.4%, 75.9%, 58.8%, 84.6% and 74.4% for modified FBP and57.1%, 82.8%. 61.5%. 80% and 74.4% for combined modified FBP and NST. There was no statistically significant difference in the longitudinal trends of umbilical artery S/D ratios in the last 3 days before delivery in each group or the last day before delivery between the two groups [P=NS]. Combined abnormal modified FBP and non-reactive NST or normal FBP and reactive NST are quite reliable in prediction or exclusion of placental inflammation in cases of preterm PROM if done on daily basis. In cases of subtle combinations of abnormal FBP and reactive NST or normal FBP and non-reactive NST, prediction of placental inflammation should be relied on the results of FBP and not on that of NST. Further studies are required to evaluate the role of umbilical artery S/D ratio in prediction of placental inflammation