The Correlation between Engagement Time of Fetal Head in Early Active Phase and Delivery Outcome in Primigravida Women

Engagement that is the passage of fetus head through the pelvic inlet is one of the main stages of delivery. There is a controversy about the engagement time in different resources. The main objective of this cross – sectional study is to determine a possible correlation between engagement time of fetal head and delivery outcome in primiparous women. This cross sectional study carried out on 471 primiparous women. The inclusion criteria were minimum height 145cm, documented term gestation 37-42 weeks, vertex presentation, single fetus, spontaneous onset of labor, cervical dilatation 4cm or less and lack of any complications. At the onset of active labor, 386 women had unengaged and 85 of them had an engaged fetal head. The data were analyzed by using t and X2 tests. Our results showed that unengagement of fetal head conferred a longer active phase as well as a longer second stage of labor (p=0.001). Furthermore, an increased need for oxytocin was observed in women with an unengaged fetal presentation (p=0.04), but the delivery method of labors, length of third stage of labor, first and fifth minute Apgar score in two groups showed no significant differences. This study showed that unengaged fetal head in early active phase although increases the duration of delivery but it does not increase delivery complications (cesarean section rate, fetal distress and low Apgar score).