Medical Care
A prolonged latent phase (see Table in Background) is not indicative of dystocia in itself because this diagnosis cannot be made in the latent phase. Gabbe and colleagues state the following: [20]
For those in the latent phase, the treatment of choice is rest for several hours. During this interval, uterine activity, fetal status, and cervical effacement must be evaluated to determine if progress to the active phase has occurred. Approximately 85% of patients so treated progress to the active phase. Approximately 10% will cease to have contractions, and the diagnosis of false labor may be made. For the approximately 5% of patients in whom therapeutic rest fails and in patients for whom expeditious delivery is indicated, oxytocin infusion may be used.
Use of oxytocin for active management of labor is described in the Medication section.
Limited studies have shown improvement in dysfunctional labor with use of a beta-blocker. In cases of dysfunctional labor resulting from functional dystocia or an abnormal uterine contractility pattern and in which oxytocin implementation has not improved the outcome, a beta-blocker may be considered. Low-dose administration of intravenous propranolol in abnormal labor augmented with oxytocin reduced the need for cesarean delivery, particularly among patients with inadequate uterine contractility. [21, 22]
Anecdotal reports have stated that simply repositioning the patient frequently relieves a seemingly obstructed labor. Although not studied rigorously, there appears to be little harm in this maneuver. In theory, it may unseat an asynclitic or malrotated presenting part and allow it to engage in the pelvis more effectively.
Some studies looked at the use of the “peanut ball”, which is an exercise ball shaped like a peanut, and found that use of it during labor significantly decreased the length of first stage of labor in nulliparous women. [23] Another study on the same topic found that both first and second stages of labor were shortened by 29 min and 11 min respectively, and cesarean delivery rate was significantly reduced. [24] Overall, given the low risk of such intervention, it appears to be worth trying in prolonged labor, particularly in nulliparous women.
Induction of labor
In a large cohort of nulliparous women who delivered singleton live births at 39-42 weeks, Cheng et al observed that induction of labor was not associated with an increased risk of cesarean delivery compared with delivery at a later gestational age. [25] Additionally, the risk of labor dystocia for women who were induced at 39 weeks (5.93%) was lower than for those expectantly managed and delivered later (6.71%; aOR, 0.88). Labor dystocia was also less likely for women who had induction at 40 weeks compared with delivery later. Additionally, no difference in risk of operative vaginal delivery, including forceps or vacuum-assisted vaginal delivery, was reported.
While these data support that induction may provide improved perinatal outcomes, without impacting labor dystocia or increasing cesarean delivery rate, the authors caution generalized implementation and recommend future large prospective, randomized, clinical trials to further assess the potential benefit in low-risk populations. [25]
Surgical Care
Amniotomy is often used and has become an accepted practice once the patient has reached the active phase of labor, although it has not been shown to result in shorter labor. [26] This practice is not recommended in the latent phase of labor because it may only serve to increase the risk of intrauterine infection or cord prolapse.
In the case of the prolonged second stage due to fetal malposition, the operator may attempt manual rotation of the fetal occiput. Studies have shown significant decrease in the rate of cesarean delivery with no increase in adverse neonatal outcomes with this maneuver [27, 9, 28]
If one of the arrest or protraction disorders is identified and fails to respond to conservative measures, or if the fetal heart pattern is nonreassuring, expedient delivery is justified; this includes operative vaginal delivery (if appropriate) or cesarean delivery as indicated. Operative delivery with use of forceps or vacuum must be performed by an experienced provider. One should be aware of the increased associations for shoulder dystocia and neonatal injury with operative vaginal delivery in the setting of abnormal labor. [29, 30]
Diet and Activity
Diet
Most institutions have standing orders that patients in labor have nothing by mouth as a precaution should the need for an emergent cesarean delivery arise.
Some institutions permit ice chips, and others permit a clear liquid diet.
If patients have been carefully selected as low risk for labor obstruction, a regular diet may be ordered.
Pregnant women have delayed gastric emptying, and aspiration is a very serious concern in the event of an anesthetic induction.
Activity
For patients in labor, remaining active and mobile while in the latent and early active phase is best. However, once rupture of membranes has occurred or signs of fetal nonreassurance exist, then bed rest and continuous fetal monitoring is appropriate.
Some clinicians allow ambulation throughout labor as long as the fetal head is well applied (minimizing risk of cord prolapse) and evidence of fetal well-being exists (monitoring for 20 min/h without signs of fetal compromise).
-
Labor curve for nulliparas.
-
Labor curve for nulliparas versus multiparas.
-
Abnormal labor curve.
-
Average labor curves by parity in singleton term pregnancies with spontaneous onset of labor. Reprinted from Seminars in Perinatology, Vol 36(5), El-Sayed YY, Diagnosis and Management of Arrest Disorders: Duration to Wait, pgs 374-8, Oct 2012, with permission from Elsevier.
-
The 95th percentiles of cumulative duration of labor from admission among singleton term nulliparous women with spontaneous onset of labor, vaginal delivery, and normal neonatal outcomes. Reprinted from Seminars in Perinatology, Vol 36(5), El-Sayed YY, Diagnosis and Management of Arrest Disorders: Duration to Wait, pgs 374-8, Oct 2012, with permission from Elsevier.
Tables
Indication |
Nullipara |
Multipara |
Prolonged latent phase |
>20 h |
>14 h |
Average second stage |
50 min |
20 min |
Prolonged second stage without (with) epidural |
>2 h (>3 h) |
>1 h (>2 h) |
Protracted dilation |
< 1.2 cm/h |
< 1.5 cm/h |
Protracted descent |
< 1 cm/h |
< 2 cm/h |
Arrest of dilation* |
>2 h |
>2 h |
Arrest of descent* |
>2 h |
>1 h |
Prolonged third stage |
>30 min |
>30 min |
*Adequate contractions >200 Montevideo units [MVU] per 10 minutes for 2 hours. (Please refer to the Pathophysiology for information regarding adequate contractions.) |
||
