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Labor: Diagnosis and management of an abnormal first stage

Labor: Diagnosis and management of an abnormal first stage
Literature review current through: Jan 2024.
This topic last updated: Jan 29, 2024.

INTRODUCTION — Recognizing abnormal labor progression and initiating appropriate intervention are important because prolonged labor is associated with increased risks for operative delivery and maternal and neonatal morbidity.

This topic will discuss diagnosis and management of abnormalities of the active phase of the first stage of labor. An overview of labor progress, risk factors for protraction and arrest disorders, diagnosis and management of abnormalities of the latent phase and second stage, and management of normal labor and delivery are reviewed separately:

(See "Labor: Overview of normal and abnormal progression".)

(See "Labor: Diagnosis and management of the latent phase".)

(See "Labor: Diagnosis and management of a prolonged second stage".)

(See "Labor and delivery: Management of the normal first stage".)

DIAGNOSIS OF ACTIVE PHASE PROTRACTION AND ARREST — By 6 cm cervical dilation, the vast majority of laboring patients will have transitioned from the latent phase to the active phase labor. (See "Labor: Diagnosis and management of the latent phase".) The diagnosis of active phase protraction and arrest disorders is based on deviation (>95th percentile) from contemporary norms in the active phase. (See "Labor: Overview of normal and abnormal progression", section on 'Contemporary observations'.)

Protraction — We make the diagnosis of a protracted active phase in nulliparous or parous patients at ≥6 cm dilation who dilate <1 to 2 cm over two hours, acknowledging that rates of dilation are slightly faster in parous patients and in those at greater dilation. Although criteria for active phase protraction were not directly addressed by the Consortium of Safe Labor, these criteria are practical for clinical management and generally consistent with the Consortium of Safe Labor data for the median 95th percentile for the time to dilate 1 cm, as shown in the table (table 1).

Arrest — We make the diagnosis of active phase arrest and consider cesarean birth in nulliparous or parous patients with ruptured membranes, cervical dilation ≥6 cm, and one of the following [1,2]:

No cervical change for ≥4 hours despite adequate contractions (assessed qualitatively or objectively defined as >200 Montevideo units [MVU] in patients with an intrauterine pressure catheter in place)

No cervical change for ≥6 hours of oxytocin administration with inadequate contractions

These criteria were proposed by both the Society for Maternal-Fetal Medicine and American College of Obstetricians and Gynecologists [2]. In the setting of no cervical change despite adequate contractions for four hours, oxytocin augmentation is not a requirement to establish the diagnosis of active phase arrest in the first stage. However, most patients with slow cervical dilation will have been started on oxytocin by this time. Our practice is to augment labor with oxytocin in patients whose membranes are ruptured and who have protracted labor even with adequate contractions, as long as the fetal heart rate tracing is reassuring. (See 'Management' below.)

The criteria were based on data from the following studies, which showed that oxytocin augmentation for at least four hours, rather than the historical standard of two hours, before diagnosing arrest is safe for the mother and fetus and increases the chances of achieving a vaginal birth. The data also showed that vaginal birth is often possible despite levels of uterine activity and rates of cervical dilation below the range historically considered necessary for success.

Evidence:

A prospective study of 542 patients in spontaneous labor at term with active phase labor arrest (defined as ≤1 cm change in dilation over four hours in a patient with cervical dilation ≥4 cm) evaluated a protocol in which oxytocin was routinely administered at diagnosis of arrest and cesarean birth for this indication was prohibited until the patient experienced at least four hours of uterine contractions >200 MVUs or, if this contraction pattern could not be achieved, the patient experienced a minimum of six hours of oxytocin augmentation [3]. Major findings were:

Only 12 percent of patients did not achieve the target 200 MVUs.

Among parous patients with cervical examinations, 46 of 233 (19.7 percent) had not made labor progress after two hours of oxytocin, but this number fell to 16 of 245 (6.5 percent) after four hours.

The eventual vaginal birth rate for parous patients was 97 percent.

-Among those who had not progressed at two hours, the eventual vaginal birth rate was 91 percent.

-Among those who had not progressed at four hours, the eventual vaginal birth rate was 88 percent.

Among nulliparous patients with cervical examinations, 80 of 239 (33.5 percent) had not made labor progress after two hours of oxytocin, but this number fell to 27 of 265 (10.2 percent) after four hours.

The eventual vaginal birth rate for nulliparous patients was 88 percent.

-Among those who had not progressed at two hours, the eventual vaginal birth rate was 74 percent.

-Among those who had not progressed at four hours, the eventual vaginal birth rate was 56 percent.

The same investigators subsequently used a standardized protocol to manage 501 consecutive, term, spontaneously laboring patients with slow labor progress [4]. The protocol involved administration of oxytocin to achieve at least 200 MVUs for four hours before considering cesarean birth.

In this study, 95 percent of parous and 80 percent of nulliparous patients eventually had a vaginal birth, whether or not they were able to achieve and/or maintain the MVU goal. Mean (fifth percentile) rates of cervical dilation in nulliparous and parous patients were 1.4 cm/hour (0.5) and 1.8 cm/hour (0.5), respectively.

In a study that analyzed data from the Consortium on Safe Labor to determine whether the degree of cervical dilation (6 versus 7 versus 8 versus 9 cm) when arrest occurs is associated with a difference in maternal and neonatal outcomes, allowing more than four hours for labor to progress 1 cm was not associated with an increased risk of maternal or neonatal morbidity at cervical dilation of 6 to 7 cm, but was associated with an increased risk of adverse outcome at 8 to 9 cm [5].

MANAGEMENT

Protraction

Oxytocin and amniotomy

Oxytocin – For patients with a protracted active phase not already on oxytocin for induction, we administer oxytocin based on extensive experience and data attesting to its safety and efficacy. Oxytocin augmentation is reasonable even in the absence of documented hypocontractile uterine activity, given that qualitative assessment of uterine activity is imprecise and quantitative measurement is invasive and of unproven benefit [6]. (See 'Oxytocin dosing' below.)

An intrauterine pressure catheter can be useful in patients with a protracted active labor or contractions that cannot be accurately monitored externally [2]. (See "Use of intrauterine pressure catheters".)

Amniotomy – We also proceed with amniotomy (if membranes are not already ruptured) as long as fetal descent is sufficient to minimize the risk of cord prolapse. If the head is not well applied to the cervix, we begin oxytocin but delay performing amniotomy. If oxytocin alone does not result in adequate progress within four to six hours, we perform an amniotomy at that time. If the head is still high and not well applied to the cervix, we perform a "controlled amniotomy" to minimize the risk of cord prolapse. (See "Umbilical cord prolapse", section on 'Minimizing risk from obstetric maneuvers'.)

Role of expectant management – Although maternal satisfaction tends to be higher with intervention in this setting [7,8] and meta-analyses of randomized trials have shown that the mean duration of labor can be shortened by intervention (eg, by 1.57 hours [95% CI -2.15 to -1.00] with early oxytocin and amniotomy [9]), cesarean birth and assisted vaginal birth rates were only minimally affected (cesarean birth RR 0.87, 95% CI 0.77-0.99 [9]) [9,10]. Thus, expectant management is also reasonable as long as at least some progress is occurring from hour to hour, especially in patients who prefer to avoid intervention. However, allowing a protracted first stage of labor in anticipation of vaginal birth should be weighed against the increased risk of composite maternal and neonatal morbidity (maternal morbidity at >95th versus <90th percentile: 24.5 and 14.1 percent, respectively; neonatal morbidity at >95th versus <90th percentile: 19.5 and 9.2 percent, respectively) [11].

Arrest – As long as labor is progressing, either slowly or normally, we continue oxytocin at the dose required to maintain an adequate uterine contraction pattern. If an arrest occurs, we proceed with a cesarean birth. (See 'Diagnosis of active phase protraction and arrest' above.)

Oxytocin dosing — Oxytocin is typically dosed to effect since predicting a patient's response to a particular dose is not possible [12]. Numerous oxytocin dosing protocols that vary in initial dose, incremental dose increase, and time interval between dose increases have been studied (table 2). Low-dose regimens were developed, in part, to avoid uterine tachysystole and are based upon the observation that it takes 40 to 60 minutes to reach steady-state oxytocin levels in maternal serum [13]. We generally do not exceed 40 milliunits/minute as the maximum dose, but others have used upper thresholds of 20 to 40 milliunits/minute (see "Induction of labor with oxytocin", section on 'Dose titration').

Compared with standard dosing, a high-dose regimen resulted in shorter labors (9.1 versus 10.5 hours) and lower incidence of chorioamnionitis incidence (10.4 versus 15.6 percent; RR 0.67, 95% CI 0.48–0.92) with no difference in cesarean birth rates in a double-blind randomized trial of over 1000 nulliparous patients [14]. However, tachysystole is more common with high-dose regimens [15,16] and the ability to quickly identify and respond to tachysystole may vary among labor and delivery units. Either a high- or low-dose oxytocin regimen is acceptable and should depend on local factors, with one important exception: a high-dose regimen is not used in patients who have had a previous cesarean birth because of the risk for uterine rupture [2,3,17,18].

Ineffective and less well-studied approaches

Misoprostol – Augmentation of labor with misoprostol is not recommended as there are only limited data on its safety and efficacy for treatment of protraction disorders [19,20]. However, in low-resource settings where safe oxytocin infusion is not feasible, low-dose titrated misoprostol may be a reasonable alternative. (See "Induction of labor: Techniques for preinduction cervical ripening", section on 'Prostaglandin E1 (misoprostol)'.)

Ambulation may improve patient comfort and is not harmful, but there is no convincing evidence that this intervention prevents or treats protraction or arrest disorders [21].

Amniotomy alone – In meta-analyses of randomized trials, routine amniotomy alone versus intention to preserve the membranes (no amniotomy) did not clearly shorten the first stage [22], whereas the combination of early oxytocin augmentation and amniotomy had favorable effects [9]. However, most of the trials did not clearly distinguish between amniotomy for prevention versus treatment of dysfunctional labor. In the only trial that randomly assigned 60 patients at term making slow progress in the first stage to amniotomy alone, amniotomy plus oxytocin, or expectant management, only the combination of amniotomy plus oxytocin increased the rate of cervical dilation; the impact on the cesarean rate was difficult to assess because the trial was underpowered for this outcome [23].

Avoiding or delaying neuraxial anesthesia – The decision to place a neuraxial anesthetic should depend upon the patient's wishes with consideration of factors, such as parity, also taken into account [24]. It can be offered for pain relief during any stage of labor [2]. In particular, concern about current or future labor progress should not be a reason to require a patient to reach an arbitrary cervical dilation, such as 4 to 5 cm, before fulfilling their request to receive neuraxial anesthesia.

Active phase arrest — Patients with labor arrest in the active phase, as defined above (see 'Arrest' above), are managed by cesarean birth. The key issue is using appropriate criteria for diagnosing labor arrest. Some unnecessary cesareans will be performed if arrest is diagnosed too soon, and the risk for maternal complications (eg, uterine rupture) are likely to increase if arrest is diagnosed too late.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Labor".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

Basics topics (see "Patient education: Labor and childbirth (The Basics)")

SUMMARY AND RECOMMENDATIONS

Overview – The general approach to diagnosis and management of labor progress is shown in the algorithm (algorithm 1).

Diagnosis

Protraction – The diagnosis of a protracted active phase is made in patients at ≥6 cm dilation who dilate <1 to 2 cm over two hours. Slow cervical dilation before 6 cm reflects the shallow slope of the latent phase portion of the normal labor curve. (See 'Protraction' above.)

Arrest – The diagnosis of first-stage active phase arrest is made in patients at ≥6 cm cervical dilation with ruptured membranes and either (see 'Arrest' above):

-No cervical change for ≥4 hours despite adequate contractions, or

-No cervical change for ≥6 hours of oxytocin administration with inadequate contractions.

Management

Protraction

-We suggest oxytocin augmentation rather than expectant management (Grade 2C) for all patients with a protracted active phase, regardless of baseline uterine activity.

We also perform amniotomy, except when the head is not well-applied to the cervix. In these cases, we begin oxytocin but delay performing the amniotomy. If oxytocin alone for four to six hours does not result in adequate progress, we consider an amniotomy at that time. A controlled amniotomy is performed if the head is still not well-applied to the cervix. (See 'Oxytocin and amniotomy' above.)

-Either a high- or low-dose oxytocin regimen is acceptable (table 2) regardless of parity, except in patients who have had a previous cesarean birth (these patients receive low-dose oxytocin). (See 'Oxytocin dosing' above.)

-In pregnancies with reassuring maternal and fetal status, if labor is progressing, either slowly or normally, we continue oxytocin at the dose required to continue cervical change. Cesarean birth is performed if arrest occurs. (See 'Oxytocin and amniotomy' above.)

Arrest – Labor arrest in the active phase is managed by cesarean birth. It is important to use appropriate criteria for diagnosis. (See 'Active phase arrest' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Robert M Ehsanipoor, MD, who contributed to earlier versions of this topic review.

  1. Zhang J, Landy HJ, Branch DW, et al. Contemporary patterns of spontaneous labor with normal neonatal outcomes. Obstet Gynecol 2010; 116:1281.
  2. First and Second Stage Labor Management: ACOG Clinical Practice Guideline No. 8. Obstet Gynecol 2024; 143:144.
  3. Rouse DJ, Owen J, Hauth JC. Active-phase labor arrest: oxytocin augmentation for at least 4 hours. Obstet Gynecol 1999; 93:323.
  4. Rouse DJ, Owen J, Savage KG, Hauth JC. Active phase labor arrest: revisiting the 2-hour minimum. Obstet Gynecol 2001; 98:550.
  5. Kawakita T, Gold SL, Huang JC, Iqbal SN. Refining the clinical definition of active phase arrest of dilation in nulliparous women to consider degree of cervical dilation as well as duration of arrest. Am J Obstet Gynecol 2021; 225:294.e1.
  6. Wei SQ, Luo ZC, Xu H, Fraser WD. The effect of early oxytocin augmentation in labor: a meta-analysis. Obstet Gynecol 2009; 114:641.
  7. Nachum Z, Garmi G, Kadan Y, et al. Comparison between amniotomy, oxytocin or both for augmentation of labor in prolonged latent phase: a randomized controlled trial. Reprod Biol Endocrinol 2010; 8:136.
  8. Selo-Ojeme DO, Pisal P, Lawal O, et al. A randomised controlled trial of amniotomy and immediate oxytocin infusion versus amniotomy and delayed oxytocin infusion for induction of labour at term. Arch Gynecol Obstet 2009; 279:813.
  9. Wei S, Wo BL, Qi HP, et al. Early amniotomy and early oxytocin for prevention of, or therapy for, delay in first stage spontaneous labour compared with routine care. Cochrane Database Syst Rev 2013; :CD006794.
  10. Bugg GJ, Siddiqui F, Thornton JG. Oxytocin versus no treatment or delayed treatment for slow progress in the first stage of spontaneous labour. Cochrane Database Syst Rev 2013; :CD007123.
  11. Blankenship SA, Raghuraman N, Delhi A, et al. Association of abnormal first stage of labor duration and maternal and neonatal morbidity. Am J Obstet Gynecol 2020; 223:445.e1.
  12. Satin AJ, Leveno KJ, Sherman ML, McIntire DD. Factors affecting the dose response to oxytocin for labor stimulation. Am J Obstet Gynecol 1992; 166:1260.
  13. Seitchik J, Amico J, Robinson AG, Castillo M. Oxytocin augmentation of dysfunctional labor. IV. Oxytocin pharmacokinetics. Am J Obstet Gynecol 1984; 150:225.
  14. Son M, Roy A, Stetson BT, et al. High-Dose Compared With Standard-Dose Oxytocin Regimens to Augment Labor in Nulliparous Women: A Randomized Controlled Trial. Obstet Gynecol 2021; 137:991.
  15. Wei SQ, Luo ZC, Qi HP, et al. High-dose vs low-dose oxytocin for labor augmentation: a systematic review. Am J Obstet Gynecol 2010; 203:296.
  16. Kenyon S, Tokumasu H, Dowswell T, et al. High-dose versus low-dose oxytocin for augmentation of delayed labour. Cochrane Database Syst Rev 2013; :CD007201.
  17. Satin AJ, Leveno KJ, Sherman ML, et al. High- versus low-dose oxytocin for labor stimulation. Obstet Gynecol 1992; 80:111.
  18. Satin AJ, Leveno KJ, Sherman ML, McIntire D. High-dose oxytocin: 20- versus 40-minute dosage interval. Obstet Gynecol 1994; 83:234.
  19. Oppenheimer LW, Labrecque M, Wells G, et al. Prostaglandin E vaginal gel to treat dystocia in spontaneous labour: a multicentre randomised placebo-controlled trial. BJOG 2005; 112:612.
  20. Vogel JP, West HM, Dowswell T. Titrated oral misoprostol for augmenting labour to improve maternal and neonatal outcomes. Cochrane Database Syst Rev 2013; :CD010648.
  21. Bloom SL, McIntire DD, Kelly MA, et al. Lack of effect of walking on labor and delivery. N Engl J Med 1998; 339:76.
  22. Smyth RM, Markham C, Dowswell T. Amniotomy for shortening spontaneous labour. Cochrane Database Syst Rev 2013; :CD006167.
  23. Blanch G, Lavender T, Walkinshaw S, Alfirevic Z. Dysfunctional labour: a randomised trial. Br J Obstet Gynaecol 1998; 105:117.
  24. American College of Obstetrics and Gynecology. ACOG practice bulletin. Obstetric analgesia and anesthesia. Number 36, July 2002. American College of Obstetrics and Gynecology. Int J Gynaecol Obstet 2002; 78:321.
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References

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