Abnormal Labor
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To define abnormal labor, a definition of normal labor must be understood and accepted. Normal labor is defined as uterine contractions that result in progressive dilation and effacement of the cervix. By following thousands of labors resulting in uncomplicated vaginal deliveries, time limits and progress milestones have been identified that define normal labor. Failure to meet these milestones defines abnormal labor, which suggests an increased risk of an unfavorable outcome. Thus, abnormal labor alerts the obstetrician to consider alternative methods for a successful delivery that minimize risks to both the mother and the infant.
Dystocia of labor is defined as difficult labor or abnormally slow progress of labor. Other terms that are often used interchangeably with dystocia are dysfunctional labor, failure to progress (lack of progressive cervical dilatation or lack of descent), and cephalopelvic disproportion (CPD).
Friedman’s original research in 1955 defined the following three stages of labor [1] :
The first stage starts with uterine contractions leading to complete cervical dilation and is divided into latent and active phases. In the latent phase, irregular uterine contractions occur with slow and gradual cervical effacement and dilation. The active phase is demonstrated by an increased rate of cervical dilation and fetal descent. The active phase usually starts at 3-4 cm cervical dilation and is subdivided into the acceleration, maximum slope, and deceleration phases.
The second stage of labor is defined as complete dilation of the cervix to the delivery of the infant.
The third stage of labor involves delivery of the placenta.
See images below for the normal labor curves of both nulliparas and multiparas. The following table shows abnormal labor indicators.
Table. Abnormal Labor Indicators (Open Table in a new window)
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.)
Abnormal labor constitutes any findings that fall outside the accepted normal labor curve. However, the authors hesitate to apply the diagnosis of abnormal labor during the latent phase because it is easy to confuse prodromal contractions for latent labor. In addition, the original labor curve, as defined by Friedman, may not be completely applicable today. [2, 3, 4, 5]
Contemporary practice with supporting data suggest that the duration of labor appears longer today than in the past. For both nulliparous and multiparous women, labor may take longer than 6 hours to progress from 4 cm to 5 cm and longer than 3 hours to progress from 5 cm to 6 cm of dilation. Cervical dilation of 6 cm appears to be a better landmark for the start of the active phase. The 95th percentile for duration of the second stage in a nulliparous woman with conduction anesthesia is closer to 4 hours. [6] Note the charts below.
As stated above, first stage of labor is divided into latent and active phases. According to Friedman et al., latent stage considered to be prolonged if takes >20 hours for nulliparous women and >14 hours for multiparous women. However, prolonged latent phase does not usually lead to any clinically significant adverse events for mother or the infant. Therefore, diagnosis of abnormal labor during the latent phase is uncommon and is not relevant for clinical practice.
Around the time uterine contractions cause the cervix to become 3-4 cm dilated, the patient usually enters the active phase of the first stage of labor, according to the traditional definition. Abnormalities of cervical dilation (protracted dilation and arrest of dilation) as well as descent abnormalities (protracted descent and arrest of descent) as described historically are outlined in the Table above.
Both American College of Obstetrics and Gynecology (ACOG) and the Consortium on Safe Labor have proposed extending the minimum period before diagnosing active-phase arrest. The Consortium on Safe Labor defines 6 hours as the 95th percentile of time to go from 4 cm to 5 cm dilation, with the active phase defined as beginning at 6 cm (instead of 4 cm). According to this study, the 95th percentile of rate of dilation in active phase is 0.5 cm/hr to 0.7 cm/hr for nulliparous women and from 0.5 cm/h to 1.3cm/hr for multiparous women. [7] ACOG has also stated that extending the time from 2 to 4 hours with oxytocin augmentation appears effective. Irrespective of the duration, maternal and fetal well-being status must be confirmed. In another study it was found that extending oxytocin augmentation for an additional 4 hours, up to 8 hours total, in patients who were dilated at least 3cm and had unsatisfactory progress resulted in a greater number of vaginal deliveries (38% delivered vaginally) without any evidence of fetal compromise. [8]
According to the most recent evidence, arrest of labor in the first stage should be defined as more than or equal to 6cm dilation with ruptured membranes and one of the following: 4 hours or more of adequate contractions (>200 MVU) or 6 hours or more of inadequate contractions and no cervical change. [9]
The maternal risk of a first stage greater than the 95th percentile (>30 h) is associated with a higher cesarean delivery rate (adjusted odds ratio [aOR]: 2.28) and chorioamnionitis (aOR: 1.58). The neonatal risk is associated with a higher incidence of neonatal ICU admissions in the absence of any other of the major morbidities (aOR: 1.53). [6] These results were again confirmed by another study, which established that prolonged first stage of labor lead to increased risks of a prolonged second stage, maternal fever, shoulder dystocia, and admission to a level 2-3 nursery [10]
The Consortium on Safe Labor also addressed the 95th percentile for the second stage for nulliparous women; it was 2.8 hours (168 min) without regional anesthesia and 3.6 hours (216 min) with regional anesthesia. For multiparous women, the 95th percentiles for second-stage duration with and without regional anesthesia remained around 2 hours and 1 hour, respectively. [6, 7] However, other studies demonstrate the risks of both maternal and perinatal adverse outcomes rising with increased duration of the second stage, particularly for durations longer than 3 hours in nulliparous women and 2 hours in multiparous women. [11] One study found that if nulliparous women delivered after prolonged second stage, they were twice as likely to have operative vaginal delivery, three times as likely to develop chorioamnionitis, have higher odds of having episiotomy and 3rd or 4th degree lacerations, and one day longer median hospital stay. [12] .Thus, careful clinical assessment of fetal and maternal well-being must be confirmed when extending the duration of the first and second stages of labor.
The third stage of labor is the time from delivery of the infant to placental delivery. Historically, the duration of a normal third stage of labor was defined as less than 30min. This threshold was established by the study conducted by Combs et al. in 1991, in which 75% of placentas were delivered by 10 minutes and maternal morbidity and mortality increased if the third stage was increased beyond 30 min. However, a recently published article by Frolova et al, puts this definition into a question. In this study, the researchers found that in a modern cohort, 90% of placentas are delivered within 10 minutes and the risk of postpartum hemorrhage almost doubles by the time the duration of third stage reaches twenty minutes. [13] Therefore, the traditional definition of prolonged third stage being >30 min, may be outdated and in need of revision.
In general, abnormal labor is the result of problems with one of the following three P’ s:
Passenger (infant size, fetal presentation [occiput anterior, posterior, or transverse])
Pelvis or passage (size, shape, and adequacy of the pelvis)
Power (uterine contractility)
A prolonged latent phase may result from oversedation or from entering labor early with a thickened or uneffaced cervix. It may be misdiagnosed in the face of frequent prodromal contractions. Protraction of active labor is more easily diagnosed and is dependent upon the 3 P’ s.
The first P, the passenger, may produce abnormal labor because of the infant’s size (eg, macrosomia) or from malpresentation.
The second P, the pelvis, can cause abnormal labor because its contours may be too small or narrow to allow passage of the infant. Both the passenger and pelvis cause abnormal labor by a mechanical obstruction, referred to as mechanical dystocia.
With the third P, the power component, the frequency of uterine contraction may be adequate, but the intensity may be inadequate. Disruption of communication between adjacent segments of the uterus may also exist, resulting from surgical scarring, fibroids, or other conduction disruption. Whatever the cause, the contraction pattern fails to result in cervical effacement and dilation. This is called functional dystocia. Uterine contractile force can be quantified by the use of an intra-uterine pressure catheter. Use of this device allows for direct measurement and calculation of uterine contractility per each contraction and is reported in Montevideo units (MVUs). For uterine contractile force to be considered adequate, the force produced must exceed 200 MVUs during a 10-minute contraction period. Arrest disorders cannot be properly diagnosed until the patient is in the active phase and had no cervical change for 2 or more hours with the contraction pattern exceeding 200 MVUs. Uterine contractions must be considered adequate to correctly diagnose arrest of dilation. [14]
United States
Of all cephalic deliveries, 8-11% are complicated by an abnormal first stage of labor. Dystocia occurs in 12% of deliveries in women without a history of prior cesarean delivery. Dystocia may account for as many as 60% of cesarean deliveries.
Both maternal and fetal mortality and morbidity rates increase with abnormal labor. This is probably an effect-effect relationship rather than a cause-effect relationship. Nonetheless, identification of abnormal labor and initiation of appropriate actions to reduce the risks are matters of some urgency.
Friedman EA. Primigravid labor; a graphicostatistical analysis. Obstet Gynecol. 1955 Dec. 6(6):567-89. [Medline].
Zhang J, Troendle JF, Yancey MK. Reassessing the labor curve in nulliparous women. Am J Obstet Gynecol. 2002 Oct. 187(4):824-8. [Medline].
Rouse DJ, Owen J, Hauth JC. Criteria for failed labor induction: prospective evaluation of a standardized protocol. Obstet Gynecol. 2000 Nov. 96(5 Pt 1):671-7. [Medline].
Cheng YW, Hopkins LM, Caughey AB. How long is too long: Does a prolonged second stage of labor in nulliparous women affect maternal and neonatal outcomes?. Am J Obstet Gynecol. 2004 Sep. 191(3):933-8. [Medline].
Rinehart BK, Terrone DA, Hudson C, Isler CM, Larmon JE, Perry KG Jr. Lack of utility of standard labor curves in the prediction of progression during labor induction. Am J Obstet Gynecol. 2000 Jun. 182(6):1520-6. [Medline].
El-Sayed YY. Diagnosis and management of arrest disorders: duration to wait. Semin Perinatol. 2012 Oct. 36(5):374-8. [Medline].
Zhang J, Landy HJ, Branch DW, et al. Contemporary patterns of spontaneous labor with normal neonatal outcomes. Obstet Gynecol. 2010 Dec. 116(6):1281-7. [Medline]. [Full Text].
Arulkumaran S, Koh CH, Ingemarsson I, Ratnam SS. Augmentation of labour–mode of delivery related to cervimetric progress. Aust N Z J Obstet Gynaecol. 1987 Nov. 27 (4):304-8. [Medline].
American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine. Obstetric care consensus no. 1: safe prevention of the primary cesarean delivery. Obstet Gynecol. 2014 Mar. 123 (3):693-711. [Medline].
Harper LM, Caughey AB, Roehl KA, Odibo AO, Cahill AG. Defining an abnormal first stage of labor based on maternal and neonatal outcomes. Am J Obstet Gynecol. 2014 Jun. 210 (6):536.e1-7. [Medline].
Allen VM, Baskett TF, O’Connell CM, McKeen D, Allen AC. Maternal and perinatal outcomes with increasing duration of the second stage of labor. Obstet Gynecol. 2009 Jun. 113(6):1248-58. [Medline].
Laughon SK, Berghella V, Reddy UM, Sundaram R, Lu Z, Hoffman MK. Neonatal and maternal outcomes with prolonged second stage of labor. Obstet Gynecol. 2014 Jul. 124 (1):57-67. [Medline].
Frolova AI, Stout MJ, Tuuli MG, López JD, Macones GA, Cahill AG. Duration of the Third Stage of Labor and Risk of Postpartum Hemorrhage. Obstet Gynecol. 2016 May. 127 (5):951-6. [Medline].
Cunningham FG, Leveno KL, Bloom SL, et al. Abnormal labor. Williams Obstetrics. 22nd ed. Appleton & Lange; 2007. 415-434.
Anim-Somuah M, Smyth R, Howell C. Epidural versus non-epidural or no analgesia in labour. Cochrane Database Syst Rev. 2005 Oct 19. CD000331. [Medline].
Gabbe SJ, O’Brien WF, Cefalo RC. Labor and delivery. Obstetrics: Normal and Problem Pregnancies. 5th ed. 2007. 322-326.
Sanchez-Ramos L, Quillen MJ, Kaunitz AM. Randomized trial of oxytocin alone and with propranolol in the management of dysfunctional labor. Obstet Gynecol. 1996 Oct. 88(4 Pt 1):517-20. [Medline].
Mitrani A, Oettinger M, Abinader EG, Sharf M, Klein A. Use of propranolol in dysfunctional labour. Br J Obstet Gynaecol. 1975 Aug. 82(8):651-5. [Medline].
Roth C, Dent SA, Parfitt SE, Hering SL, Bay RC. Randomized Controlled Trial of Use of the Peanut Ball During Labor. MCN Am J Matern Child Nurs. 2016 May-Jun. 41 (3):140-6. [Medline].
Tussey CM, Botsios E, Gerkin RD, Kelly LA, Gamez J, Mensik J. Reducing Length of Labor and Cesarean Surgery Rate Using a Peanut Ball for Women Laboring With an Epidural. J Perinat Educ. 2015. 24 (1):16-24. [Medline].
Cheng YW, Kaimal AJ, Snowden JM, Nicholson JM, Caughey AB. Induction of labor compared to expectant management in low-risk women and associated perinatal outcomes. Am J Obstet Gynecol. 2012 Dec. 207(6):502.e1-8. [Medline].
Smyth RM, Alldred SK, Markham C. Amniotomy for shortening spontaneous labour. Cochrane Database Syst Rev. 2007 Oct 17. CD006167. [Medline].
Le Ray C, Serres P, Schmitz T, Cabrol D, Goffinet F. Manual rotation in occiput posterior or transverse positions: risk factors and consequences on the cesarean delivery rate. Obstet Gynecol. 2007 Oct. 110 (4):873-9. [Medline].
Shaffer BL, Cheng YW, Vargas JE, Caughey AB. Manual rotation to reduce caesarean delivery in persistent occiput posterior or transverse position. J Matern Fetal Neonatal Med. 2011 Jan. 24 (1):65-72. [Medline].
Mollberg M, Hagberg H, Bager B, Lilja H, Ladfors L. Risk factors for obstetric brachial plexus palsy among neonates delivered by vacuum extraction. Obstet Gynecol. 2005 Nov. 106(5 Pt 1):913-8. [Medline].
Mehta SH, Bujold E, Blackwell SC, Sorokin Y, Sokol RJ. Is abnormal labor associated with shoulder dystocia in nulliparous women?. Am J Obstet Gynecol. 2004 Jun. 190(6):1604-7; discussion 1607-9. [Medline].
Shields SG, Ratcliffe SD, Fontaine P, Leeman L. Dystocia in nulliparous women. Am Fam Physician. 2007 Jun 1. 75(11):1671-8. [Medline].
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 May. 112(5):612-8. [Medline].
Butchart AG, Mathews M, Surendran A. Complex regional pain syndrome following protracted labour*. Anaesthesia. 2012 Nov. 67(11):1272-4. [Medline].
Treacy A, Robson M, O’Herlihy C. Dystocia increases with advancing maternal age. Am J Obstet Gynecol. 2006 Sep. 195(3):760-3. [Medline].
Zhu BP, Grigorescu V, Le T, et al. Labor dystocia and its association with interpregnancy interval. Am J Obstet Gynecol. 2006 Jul. 195(1):121-8. [Medline].
Zuo Z, Goel S, Carter JE. Association of cervical cytology and HPV DNA status during pregnancy with placental abnormalities and preterm birth. Am J Clin Pathol. 2011 Aug. 136(2):260-5. [Medline].
Cheng YW, Hopkins LM, Laros RK Jr, Caughey AB. Duration of the second stage of labor in multiparous women: maternal and neonatal outcomes. Am J Obstet Gynecol. 2007 Jun. 196(6):585.e1-6. [Medline].
Friedman EA. Labor in multiparas; a graphicostatistical analysis. Obstet Gynecol. 1956 Dec. 8(6):691-703. [Medline].
Hoffman MK, Vahratian A, Sciscione AC, Troendle JF, Zhang J. Comparison of labor progression between induced and noninduced multiparous women. Obstet Gynecol. 2006 May. 107(5):1029-34. [Medline].
Vahratian A, Hoffman MK, Troendle JF, Zhang J. The impact of parity on course of labor in a contemporary population. Birth. 2006 Mar. 33(1):12-7. [Medline].
Wood S, Ross S, Sauve R. Cesarean section and subsequent stillbirth, is confounding by indication responsible for the apparent association? An updated cohort analysis of a large perinatal database. PLoS One. 2015. 10(9):e0136272. [Medline].
Chaiworapongsa T, Romero R, Whitten AE, et al. The use of angiogenic biomarkers in maternal blood to identify which SGA fetuses will require a preterm delivery and mothers who will develop pre-eclampsia. J Matern Fetal Neonatal Med. 2015 Aug 25. 1-15. [Medline].
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.)
Nina S Olsen, MD Resident Physician, Department of Obstetrics and Gynecology, Virginia Commonwealth University School of Medicine
Nina S Olsen, MD is a member of the following medical societies: American Academy of Family Physicians, American College of Obstetricians and Gynecologists, American College of Physicians, Virginia Academy of Family Physicians
Disclosure: Nothing to disclose.
Nicole W Karjane, MD Associate Professor, Department of Obstetrics and Gynecology, Virginia Commonwealth University Medical Center
Nicole W Karjane, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, Association of Professors of Gynecology and Obstetrics, North American Society for Pediatric and Adolescent Gynecology
Disclosure: Received income in an amount equal to or greater than $250 from: Merck<br/>Served as Nexplanon trainer for: Merck.
Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
John G Pierce, Jr, MD Associate Professor, Departments of Obstetrics/Gynecology and Internal Medicine, Medical College of Virginia at Virginia Commonwealth University
John G Pierce, Jr, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, Association of Professors of Gynecology and Obstetrics, Christian Medical and Dental Associations, Medical Society of Virginia, Society of Laparoendoscopic Surgeons
Disclosure: Nothing to disclose.
Ronald M Ramus, MD Professor of Obstetrics and Gynecology, Director, Division of Maternal-Fetal Medicine, Virginia Commonwealth University School of Medicine
Ronald M Ramus, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, Medical Society of Virginia, Society for Maternal-Fetal Medicine
Disclosure: Nothing to disclose.
Robert K Zurawin, MD Associate Professor, Chief, Section of Minimally Invasive Gynecologic Surgery, Department of Obstetrics and Gynecology, Baylor College of Medicine
Robert K Zurawin, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Society for Reproductive Medicine, Association of Professors of Gynecology and Obstetrics, Central Association of Obstetricians and Gynecologists, Society of Laparoendoscopic Surgeons, Texas Medical Association, AAGL, Harris County Medical Society, North American Society for Pediatric and Adolescent Gynecology
Disclosure: Received consulting fee from Ethicon for consulting; Received consulting fee from Bayer for consulting; Received consulting fee from Hologic for consulting.
Deborah Lyon, MD Director, Division of Gynecology, Associate Professor, Department of Obstetrics and Gynecology, University of Florida Health Science Center at Jacksonville
Deborah Lyon, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, Association of American Medical Colleges, Association of Professors of Gynecology and Obstetrics, Florida Medical Association
Disclosure: Nothing to disclose.
Saju Joy, MD, MS Associate Director, Division Chief of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Carolinas Medical Center
Saju Joy, MD, MS is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, Society for Maternal-Fetal Medicine, American Medical Association
Disclosure: Nothing to disclose.
Patricia L Scott, MD Tennessee Maternal-Fetal Medicine
Patricia L Scott, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, Tennessee Medical Association
Disclosure: Nothing to disclose.
Abnormal Labor
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