Meconium-stained liquor during labor is associated with raised neonatal cord blood 8-iso-prostaglandin F2α concentration

Objective The purpose of this study was to compare the umbilical arterial 8-iso-prostaglandin F2α, concentrations between pregnancies that were complicated by moderate or thick meconium-stained liquor and those with clear liquor. Study design Umbilical cord arterial blood samples were collected from 247 singleton pregnancies with either moderate or thick meconium-stained liquor at any stage of labor or clear liquor at all stages of labor for the determination of the total 8-iso-prostaglandins F2α concentration. Results The median total 8-iso-prostaglandins F2α concentration of the meconium-stained liquor group was significantly higher than that of the control group (719.2 vs 115.8 pg/mL). Among the meconium-stained liquor group, those who had a change from “clear liquor” at early labor to “moderate/ thick meconium-stained liquor” at late first stage or at delivery (late meconium-stained liquor group) had higher 8-iso-prostaglandins F2α concentration, compared with those who had moderate/ thick meconium-stained liquor since early labor (early meconium-stained liquor group; 959.8 vs 499.9 pg/mL). With the use of multiple regression analysis, meconium-stained liquor, duration of second stage of labor, and abnormal fetal heart tracings were independent determinants of cord blood 8-iso-prostaglandins F2α concentration. Conclusion Moderate or thick meconium-stained liquor is an independent factor for increased oxidative stress in pregnancy.