Labor and delivery in nulliparous women who present with an unengaged fetal head

Abstract

Objective: We assessed the relation of fetal station in early labor to subsequent patterns of dilation and descent and to the probability of cesarean delivery.

Study design: We evaluated 132 nulliparous women who were in spontaneous latent-phase labor with singleton, vertex-presenting, term fetuses. For each participant, pertinent variables relating to labor characteristics and mode of delivery and newborn characteristics were recorded. Labor curves were drawn and analyzed.

Results: Of the 132 participants, 29 (22%) presented with an engaged fetal head, and 103 (78%) presented with an unengaged fetal head. In the unengaged group, 15 (11%) presented with a floating fetal head (-3 station or above), and 88 (67%) presented with a dipping fetal head (-2 or -1 station). A floating head in latent-phase labor conferred a longer second stage (p = 0.02), a trend to more active-phase labor disorders (p = 0.06), and a greater risk of cesarean delivery. Overall, 12 patients (9%) underwent primary cesarean section: 2 (6.9%) from the engaged group, 6 (6.8%) from the dipping group, and 4 (27%) from the floating group (p = 0.042).

Conclusion: Most nulliparous women in this study presented in labor with an unengaged fetal head. Those with a floating fetal head demonstrated higher rates of cesarean section than those with dipping or engaged heads in early labor.