Final answer:
In active labor, contractions typically occur every 1.5-2 minutes and last around one full minute. The intensity of contractions increases due to oxytocin secretion stimulated by cervical dilation. True labor contractions signal the progression of childbirth and are distinguishable from false labor by their increasing regularity and strength.
Step-by-step explanation:
The frequency, length, and intensity of contractions corresponding to active labor indicate the progression of childbirth. During the first stage of labor, uterine contractions may begin infrequently, occurring every 3-30 minutes and lasting 20-40 seconds. As labor progresses, these contractions become more regular, frequent, and intense. In the active phase, contractions often occur as frequently as every 1.5-2 minutes and may last for up to one full minute. True labor contractions do not abate with hydration or rest and are distinguished from false labor by their increasing frequency and intensity. The stretching of the myometrium and cervix, especially when the fetus is in the vertex position, stimulates these regular and powerful contractions. Additionally, cervical dilation causes an increase in the secretion of oxytocin, which further enhances the intensity of the contractions, contributing to the continuation of labor.
There are three stages in the labor process. In the second stage, after the cervix has fully dilated to about 10 centimeters, the baby is expelled. The third stage involves the passage of the placenta from the uterus. If labor stalls before the second stage is reached, synthetic oxytocin, known as Pitocin, may be administered to restart and maintain labor contractions.