Which stage of labor encompasses the latent and active phases and ends with complete cervical dilation and effacement?

• A. Second stage
• B. Third stage
• C. First stage
• D. Fourth stage

Answer: (C)

Staging of labor is defined by cervical changes during contractions. The first stage spans from the onset of true labor to the moment the cervix is fully dilated and effaced. It comprises two phases: latent, where dilation progresses gradually from around 0 to about 3 cm with milder, irregular contractions; and active, where dilation speeds up toward complete dilation as contractions become stronger and more regular. The end point of this stage is complete cervical dilation (10 cm) with full effacement, after which pushing begins in the next stage. The second stage runs from full dilation to the baby’s birth, the third stage from birth to placental delivery, and the fourth stage refers to the immediate postpartum period.