Final answer:
The transition phase of labor is identified by strong contractions that are about 1 to 2 minutes apart, significant cervical dilation (8 to 10 cm), and the client may experience increased pressure, shaking, or nausea.
Step-by-step explanation:
The assessment finding that reveals that the transition phase of labor has started is typically indicated by very strong and frequent contractions, usually about 1 to 2 minutes apart, lasting 60 to 90 seconds. The cervix will dilate to around 8 to 10 cm. The transition phase is the most intense and typically the shortest part of labor, leading up to the point where it's time to push and deliver the baby.
During the transition phase, the laboring client may also experience increased pressure in the back or rectum, shaking, nausea, and a desire to bear down or push. These signs accompany the physical findings that indicate the transition phase is underway, representing the final stage of cervical dilation before childbirth.
The nursing assessment finding that reveals the transition phase of labor has started is the regular contractions known as true labor. True labor contractions immediately precede childbirth, do not abate with hydration or rest, and become more frequent and powerful with time. This indicates that the cervix is progressively dilating and effacing, leading to the progress of labor.