“…No significant associations were reported between prolonged second stage in multiparous women and umbilical artery pH < 7.0, umbilical artery pH < 7.10, umbilical artery base excess ≥12, meconium aspiration, shoulder dystocia, prolonged neonatal stay, advanced neonatal resuscitation, birth depression, minor or major trauma or any perinatal morbidity. After combining two studies [19,29], only an increase in the risk of meconium staining was observed (OR, 1.29; 95%CI, 1.01-1.66), and an increase in composite neonatal morbidity (OR,1.97; 95% CI, 1.39-2.80) was observed after another two studies were combined [19,23] (Table 3).…”