A 20-year-old G1 at 38 weeks’ gestation presents with regular painful contractions every 3 to 4 minutes lasting 60 seconds. On pelvic examination, she is 3-cm dilated and 90% effaced; an amniotomy is performed and clear fluid is noted. The patient receives epidural analgesia for pain management. The fetal heart rate (FHR) tracing is reactive. One hour later on repeat examination, her cervix is 5-cm dilated and 100% effaced.
For the description of labor, select the most appropriate next step in management.
Patient has normal labor; no intervention is needed at this time.
A 30-year-old G2P0 at 39 weeks is admitted in labor with spontaneous rupture of membranes occurring 2 hours prior to admission and regular uterine contractions. On examination, her cervix is 4-cm dilated and completely effaced. The fetal head is at 0 station and the fetal heart tracing is reactive. Two hours later, on repeat examination, her cervix is 5-cm dilated and the fetal head is at +1 station. Early decelerations are noted on the fetal heart tracing.
The patient has a protracted active phase of labor (cervical dilation < 1.2 cm/h). Either expectant management or Pitocin augmentation may be used for treatment.
You are following a 38-year-old G2P1 at 39 weeks in labor. She has had one prior vaginal delivery of a 3800-g infant. One week ago, the estimated fetal weight was 3200 g by ultrasound. Over the past 3 hours her cervical examination remains unchanged at 6 cm. The FHR tracing is reactive. An IUPC reveals two contractions in 10 minutes with amplitude of 40 mm Hg each.
The best evidence available indicates that this labor is hypotonic and that the contractions are inadequate. Two contractions of 40 mm Hg intensity during a 10-minute period equates to 80 MVUs. About 200 MVUs are needed to consider contractions to be adequate to affect delivery. Since the ultrasound indicates a fetus without obvious abnormalities and smaller than her first infant, we assume the absence of cephalopelvic disproportion (CPD). Oxytocin is the treatment of choice in this situation.
You are following a 22-year-old G2P1 at 39 weeks in labor. At 4-cm dilated she is given an epidural for pain management. Three hours later, her cervical examination is unchanged. Her contractions are now every 2 to 3 minutes, lasting 60 seconds. The FHR tracing is 120 beats per minute with accelerations and early decelerations.
Arrest of labor cannot be diagnosed during the first stage of labor until the cervix has reached 4-cm dilation and until adequate uterine contractions (both in frequency and intensity) have been documented. The actual pressure within the uterus cannot be measured via an external tocodynamometer; an IUPC needs to be placed. It is generally accepted that 200 MVUs (number of contractions in 10 minutes × average contraction intensity in mm Hg) are required for normal labor progress.
The patient is having adequate uterine contractions as determined by the IUPC. Therefore, augmentation with Pitocin is not indicated. The patient’s diagnosis is secondary arrest of labor, which requires cesarean delivery. In the active phase of labor, a multiparous patient should undergo dilation of the cervix at a rate of at least 1.5 cm/h if uterine contractions are adequate.
Click to expand