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

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

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.

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).

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.