Pattern of uterine contractions can be evaluated using external monitoring as well as internal. With the start of
contractions and increase of intrauterine pressure, the height of the contraction curve increases and decreases
following reduced intrauterine pressure (Gonçalves, Pinto, Ayres-de-Campos, & Bernardes, 2014). One
landmark for evaluating quality of a contraction is F/R ratio which means the time that a contraction needs to
return from its peak to baseline (Fall) divided to the time for a contraction to rise to its peak (Rise). In the case of
a CPD, the interval between contractions increases and the height of the contraction curve is reduced, a warning
sign for re-evaluating the patient.