Abnormalities of the First and Second Stages of Labor

https://doi.org/10.1016/j.ogc.2005.01.007Get rights and content

Section snippets

Diagnosis and terminology

Dystocia (literally: δυς, abnormal or difficult, and τοκος, labor or delivery, in ancient Greek) is characterized by slow progress or (eventual) arrest of labor. When it results in a CD, the diagnosis is usually described as cephalopelvic disproportion (CPD) or failure to progress. Originally, CPD described obstructed labors occurring as a result of pelvic contracture caused by rickets. Fortunately today, true pelvic contracture is rare and CPD is a subjective diagnosis based on a clinical

Abnormalities of the first stage

The first stage of labor begins with the onset of labor and ends at complete cervical dilatation. It is divided into a latent, early phase, followed by an active phase. Abnormalities of the first stage of labor have been reported in 8% to 11% of women in labor [4], [5]. Sheiner et al [6] studied 92,918 term, singleton, vertex pregnancies, and found that independent risk factors for CD for failure to progress were induction, maternal age greater than 35, fetal weight greater than 4 kg,

Defining the beginning of labor

Friedman [4] defined the beginning of the latent phase (the onset of labor) as the time at which the mother recognizes regular contractions. This definition is overly inclusive because pregnant women may perceive painful contractions at any time in pregnancy, especially near term. If a more strict definition of labor, such as painful contractions associated with cervical change (effacement and dilatation), is used, a similar problem is encountered because effacement and dilatation may occur

Active phase disorders

Disorders of the active phase are common and can be seen in up to 25% of nulliparous labors and in 15% of labors in multiparas [25]. Progress of active labor is usually assessed with vaginal examinations every 2 to 3 hours (try to keep to less than seven to eight examinations total). Given the high interobserver variability of digital cervical examinations, cervical examination by vaginal ultrasound has been advocated for assessment of the adequacy of labor. One study has demonstrated that the

Disorders of the active phase

The disorders of the active phase have been divided into a number of overlapping categories by various investigators. The three major categories are:

  • 1.

    Protracted or prolonged active phase, also called primary dysfunctional labor

  • 2.

    Arrest of dilatation or descent, also called secondary arrest

  • 3.

    Combined disorder

A protracted active phase means that, after entering what should be the active phase (3–4 cm), the rate of cervical dilatation is slow. This is defined statistically as less than the fifth

Management of active phase disorders

Box 2 presents a summary of management of active phase disorders.

Intrapartum strategies to reduce the risk of dystocia

A number of additional, general labor strategies have been studied in an effort to reduce the risk of dystocia (Box 3). These include ambulation, maternal position in labor, continuous support, hydration, and judicious anesthesia.

Second stage of labor (arrest of descent)

Descent and rotation are the primary labor processes in the second stage (Box 4). A large study by Fraser et al found that risk factors for a “difficult delivery” in nulliparas in the second stage of labor were abnormal fetal position; high fetal station at full dilatation (above −2 station); advanced maternal age (>35 years); and maternal height less than 160 cm [47], [47a]. Epidural use was also associated with a difficult delivery, but only if it was placed before 3 cm or after 5 cm. If the

Summary

Abnormalities of the first and second stage of labor are common. Aside from the recommendations of Rouse et al to allow longer oxytocin augmentation in the active phase, there are currently no evidence-based, uniform definitions or guidelines for the management of abnormal labor [21], [38], [40], [41], [53]. Based on the work of various investigators and the authors' own experience, this article summarizes the important considerations and management options for the various phases of labor. The

First page preview

First page preview
Click to open first page preview

References (54)

  • M. Gardberg et al.

    Intrapartum sonography and persistent occiput posterior position: a study of 408 deliveries

    Obstet Gynecol

    (1998)
  • T.J. Garite et al.

    A multicenter controlled trial of fetal pulse oxymetry in the intrapartum management of nonreassuring fetal heart rate patterns

    Am J Obstet Gynecol

    (2000)
  • D. Rouse et al.

    Active phase labor arrest: revisiting the 2-hour minimum

    Obstet Gynecol

    (2001)
  • D. Rouse et al.

    Active-phase labor arrest: oxytocin augmentation for at least 4 hours

    Obstet Gynecol

    (1999)
  • T. Garite et al.

    A randomized controlled trial of the effect of increased intravenous hydration on the course of labor in nulliparous women

    Am J Obstet Gynecol

    (2000)
  • W.D. Fraser et al.

    Risk factors for difficult delivery in nulliparas with epidural analgesia in the second stage of labor

    Am J Obstet Gynecol

    (2002)
  • L. Hellman et al.

    The duration of the second stage of labor

    Am J Obstet Gynecol

    (1952)
  • S. Menticoglou et al.

    Perinatal outcome in relation to second stage: perinatal outcome in relation to second-stage duration

    Am J Obstet Gynecol

    (1995)
  • T. Myles et al.

    Maternal and neonatal outcomes in patients with a prolonged second stage

    Obstet Gynecol

    (2003)
  • B. Plunkett et al.

    Management of the second stage of labor in nulliparas with continuous epidural anesthesia

    Obstet Gynecol

    (2003)
  • S. Hansen et al.

    Active pushing versus passive fetal descent in the second stage of labor: a randomized controlled trial

    Obstet Gynecol

    (2002)
  • G.F. Cunningham et al.

    Section V. Abnormal labor

  • E. Friedman

    Labor: clinical evaluation and management

    (1978)
  • R. Philpott et al.

    Cervicographs in the management of labour in the primigravidae. I. The alert line for detecting abnormal labor

    J Obstet Gynaecol Br Commonw

    (1972)
  • E. Sheiner et al.

    Risk factors and outcome of failure to progress during the first stage of labor: a population based study

    Acta Obstet Gynecol Scand

    (2002)
  • C. Hendricks et al.

    Normal cervical dilatation pattern in late pregnancy and labor

    Am J Obstet Gynecol

    (1970)
  • S. Kilpatrick et al.

    Characteristics of normal labor

    Obstet Gynecol

    (1989)
  • Cited by (20)

    • Effect of hyoscine butyl-bromide on the duration of active phase of labor: A randomized-controlled trial

      2017, Taiwanese Journal of Obstetrics and Gynecology
      Citation Excerpt :

      In un-augmented labor, HBB did not produce any significant difference in the duration of labor when compared to placebo, among both multipara and primigravidae in the present study. These observations may be due to the fact that slow progress of labor among primigravidae is mostly due to uterine inertia [20] and oxytocin-augmentation would invariably correct this dystocia in most primigravid parturient. It is also well established that HBB has no effect on uterine contractions; its actions in labor are mainly on the cervix, as an antispasmodic agent [4].

    • Exercise during pregnancy and risk of cesarean delivery in nulliparous women: a large population-based cohort study

      2016, American Journal of Obstetrics and Gynecology
      Citation Excerpt :

      The most common indication for CD in nulliparous women is dystocia, which includes problems of uterine dysfunction, impaired cervical dilation, and/or fetal descent in the maternal pelvis.34 Dystocia is generally thought to be due to insufficient uterine contractions.35 Recently, athletics and heavy gardening have been found to be protective of dystocia in nulliparous women.36

    • What is normal progress in the first stage of labour? A vignette study of similarities and differences between midwives and obstetricians

      2016, Midwifery
      Citation Excerpt :

      While primary-care midwives are the initiators of a referral due to a prolonged first stage of labour, the expectations and actions of all the different care professionals need to be well attuned. Guidelines on a prolonged first stage of labour are readily available (Ness et al., 2005; NICE - National Institute for Health and Care Excellence, 2014). However, it is unclear what information different obstetrical professionals use to assess a prolonged first stage of labour and to decide when to refer to a clinical setting.

    • Proposed biological linkages between obesity, stress, and inefficient uterine contractility during labor in humans

      2011, Medical Hypotheses
      Citation Excerpt :

      Dystocia, a general term indicating difficult labor, includes the related labor problems of uterine dysfunction, and impaired cervical dilatation and/or delayed fetal descent in the maternal pelvis. For reasons that remain obscure, nulliparous women are particularly vulnerable to a diagnosis of dystocia during labor with inadequate uterine activity (i.e., uterine dysfunction) cited as the most common cause of dystocia in these women [5]. The occurrence of dystocia in the United States is apparently increasing, as reflected in the rising cesarean section rate among healthy nulliparous women at term with a single fetus in a head down position.

    • Evidence-based labor and delivery management

      2008, American Journal of Obstetrics and Gynecology
    View all citing articles on Scopus
    View full text