What is the best description of the active phase in the first stage of labor?

The active phase of the first stage of labor is defined as the period when the cervix dilates from 4 cm to 7 cm. During this phase, labor progresses more rapidly compared to the earlier stage, known as the latent phase, when dilation occurs more slowly, typically from 0 to 3 cm.

In the active phase, contractions become more frequent, regular, and intense, which facilitates further cervical dilation and effacement. Monitoring during this stage is critical, as it is when significant changes in the laboring woman's condition can occur, leading to the later stages of labor.

The other stages of cervical dilation mentioned do not pertain to the active phase. The transition from 0 to 3 cm is part of the latent phase, while 8 to 10 cm indicates the transition phase as labor approaches delivery. Additionally, complete effacement, while significant, describes the state of the cervix rather than the degree of dilation that characterizes the active phase.