Relationship between fetal station and successful vaginal delivery in nulliparous women.

In early studies by Friedman and Sachtleben, a high fetal station on presentation was associated with a dysfunctional labor pattern.1–4 Subsequent studies examined the relationship between fetal station and cesarean delivery and demonstrated that an unengaged vertex at the time of active labor is associated with a significantly increased chance of cesarean delivery.4–7 Yet, the relevance of these findings to the present day is uncertain as obstetric practice has been characterized by a decreased frequency of operative vaginal delivery and an increased frequency of cesarean delivery.8 The demographic characteristics of reproductive-aged women in the United States have also changed such that the pregnant women are more likely to be older and have a greater body mass index (BMI).9,10 Both of these factors have been linked to higher rates of cesarean delivery.11–13 Thus, in the context of the present obstetric population and the approach to medical care, the relationship between station at admission for labor and vaginal delivery remains uncertain. This secondary analysis of detailed labor data from the modern era was performed to estimate the association between fetal station at admission and subsequent vaginal delivery.