The comparison of umbilical cord artery pH in newborns with and without thick meconium stained amniotic fluid

Meconium-stained amniotic fluid (MSAF) affects 15-20% of term pregnancies. Recent studies have shown that MSAF has adverse effects on neonatal outcomes. There is no scientific consensus on the incidence of fetal distress in MSAF neonates, and most cesarean sections due to MSAF are unnecessary. The present study was conducted to assess umbilical artery blood pH in neonates with MSAF and to examine whether there is a relationship between MSAF and fetal distress. A clinical survey case-control was conducted on the neonates of 200 pregnant women admitted to a delivery unit of the obstetrics and Gynecology center in Amir al-Momenin Hospital, Zabol in 2014. Neonates born with MSAF made up the case group, and the control group consisted of neonates born with clear amniotic fluid. Umbilical cord arterial pH, gestational age, gender, mode of delivery, and one and five-minute Apgar scores were considered in both groups. The mean pH of the umbilical cord artery blood in the infants of the case group was 7.25, and the mean pH of the umbilical cord artery in the infants of the control group was 7.29 (P = 0.93). The mean gestational age in the case and control groups was 40.08 weeks and 38.32 weeks, respectively (P= 0.03). In this study, a cesarean delivery (P=0.001) and female gender (P= 0.016) were higher in the case group than in the control group. MSAF does not necessarily imply fetal distress, so urgent cesarean sections are unnecessary. This study showed that based on the acidity variables of the umbilical cord artery, there is no statistically significant correlation between the Apgar score at the 1st and 5th minute. While a significant difference has been observed between the type of delivery, gestational age and baby’s gender.