The factors that affect the process of labor and birth, known commonly as the five Ps, include all except:

Choice A rationale
Fetal sleep cycles cause temporary decreased variability in FHR, typically lasting 20 minutes or less. FHR baseline remains normal. Normal FHR variability is 6-25 bpm.
Choice B rationale
Head compression during contractions leads to early decelerations in FHR, not decreased variability. Early decelerations are a normal response to pressure on the fetal head.
Choice C rationale
Fetal hypoxemia causes decreased variability but usually persists for longer than 20 minutes. It indicates compromised oxygen supply, requiring immediate intervention.
Choice D rationale
Umbilical cord compression leads to variable decelerations in FHR rather than decreased variability. These decelerations vary in onset, duration, and intensity.

Choice A rationale
The tocodynamometer detects both the frequency and intensity of uterine contractions by measuring the pressure changes on the abdomen. It provides real-time data on contraction patterns during labor.
Choice B rationale
Repeating the frequency and intensity of contractions is redundant. The tocodynamometer accurately measures these parameters, providing essential information for managing labor progress.
Choice C rationale
While the tocodynamometer can infer uterine resting tone, it is not designed to measure hypertonus directly. Other methods, like intrauterine pressure catheters, offer more accurate assessments of uterine tone.
Choice D rationale
The tocodynamometer measures the duration of contractions, but it does not solely focus on this parameter. It captures comprehensive data, including frequency and intensity, for effective labor management.