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Hamilton EF, Romero R, Tarca AL, Warrick PA. The evolution of the labor curve and its implications for clinical practice: the relationship between cervical dilation, station, and time during labor. Am J Obstet Gynecol 2023; 228:S1050-S1062. [PMID: 37164488 PMCID: PMC10445404 DOI: 10.1016/j.ajog.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 03/18/2023]
Abstract
The assessment of labor progress is germane to every woman in labor. Two labor disorders-arrest of dilation and arrest of descent-are the primary indications for surgery in close to 50% of all intrapartum cesarean deliveries and are often contributing indications for cesarean deliveries for fetal heart rate abnormalities. Beginning in 1954, the assessment of labor progress was transformed by Friedman. He published a series of seminal works describing the relationship between cervical dilation, station of the presenting part, and time. He proposed nomenclature for the classification of labor disorders. Generations of obstetricians used this terminology and normal labor curves to determine expected rates of dilation and fetal descent and to decide when intervention was required. The analysis of labor progress presents many mathematical challenges. Clinical measurements of dilation and station are imprecise and prone to variation, especially for inexperienced observers. Many interrelated factors influence how the cervix dilates and how the fetus descends. There is substantial variability in when data collection begins and in the frequency of examinations. Statistical methods to account for these issues have advanced considerably in recent decades. In parallel, there is growing recognition among clinicians of the limitations of using time alone to assess progress in cervical dilation in labor. There is wide variation in the patterns of dilation over time and most labors do not follow an average dilation curve. Reliable assessment of labor progression is important because uncertainty leads to both over-use and under-use of cesarean delivery and neither of these extremes are desirable. This review traces the evolution of labor curves, describes how limitations are being addressed to reduce uncertainty and to improve the assessment of labor progression using modern statistical techniques and multi-dimensional data, and discusses the implications for obstetrical practice.
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Affiliation(s)
- Emily F Hamilton
- Department of Obstetrics and Gynecology, McGill University, Montreal, Canada; PeriGen Inc, Cary, NC.
| | - Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, and Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI; Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI; Department of Obstetrics and Gynecology, Detroit Medical Center, Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI
| | - Adi L Tarca
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, and Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI; Department of Computer Science, Wayne State University College of Engineering, Detroit, MI
| | - Philip A Warrick
- PeriGen Inc, Cary, NC; Department of Biomedical Engineering, McGill University, Montreal, Canada
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Shindo R, Aoki S, Misumi T, Nakanishi S, Umazume T, Nagamatsu T, Masuyama H, Itakura A, Ikeda T. Spontaneous labor curve based on a retrospective multi-center study in Japan. J Obstet Gynaecol Res 2021; 47:4263-4269. [PMID: 34622514 PMCID: PMC9291815 DOI: 10.1111/jog.15053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/12/2021] [Accepted: 09/24/2021] [Indexed: 11/27/2022]
Abstract
Aim In Japan, the criteria of the latent and active phases of the first stage of labor have not been decided. The Japan Society of Obstetrics and Gynecology (JSOG) Perinatal Committee conducted a study to construct a spontaneous labor curve in order to determine the point of onset of the active phase. Methods The participants were women who had spontaneous deliveries at four health facilities in Japan between September 1, 2011, and September 31, 2019. Spontaneous delivery was defined as the spontaneous onset of labor at term (37 weeks, 0 days to 41 weeks, 6 days) with vaginal delivery of a mature fetus in a cephalic position without uterotonic agents or epidural analgesia. The time points for each “cm” of dilation were collected starting from the time of full dilation retrogradely. The relationship between time since labor onset and cervical dilation was expressed as a curve using a smoothing B‐spline. Results A total of 4215 primiparous and 5266 multiparous women were included in this study. The spontaneous labor curve showed that in both primiparous and multiparous women, labor progress was slow until 5 cm cervical dilation, accelerating between 5 and 6 cm dilation, and steadily progressed after 6 cm dilation. Conclusion We propose that the active phase of the first stage of labor be defined as starting at 5 cm dilation of the cervix, and that it be divided into an acceleration phase (5–6 cm dilation) and a maximal phase (>6 cm dilation).
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Affiliation(s)
- Ryosuke Shindo
- Perinatal Center for Maternity and Neonates, Yokohama City University Medical Center, Yokohama, Japan
| | - Shigeru Aoki
- Perinatal Center for Maternity and Neonates, Yokohama City University Medical Center, Yokohama, Japan
| | - Toshihiro Misumi
- Department of Biostatistics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Sayuri Nakanishi
- Perinatal Center for Maternity and Neonates, Yokohama City University Medical Center, Yokohama, Japan
| | - Takeshi Umazume
- Department of Obstetrics and Gynecology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Takeshi Nagamatsu
- Department of Obstetrics and Gynecology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hisashi Masuyama
- Department of Obstetrics and Gynecology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Atsuo Itakura
- Department of Obstetrics and Gynecology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Tomoaki Ikeda
- Department of Obstetrics and Gynecology, Mie University School of Medicine, Mie, Japan
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Shazly SA, Shawki AA, Ahmed MM, Monib FA, Radwan AA, Sedik AS, Said AE, Ali SS, Abouzeid MH, Sayed EG, Nassr AA, Eltaweel NA, Hortu I, Hassan RM, Abdelbadie AS. Middle-East OBGYN graduate education (MOGGE) foundation practice guidelines: use of labor charts in management of labor. Practice guideline no. 04-O-21. J Matern Fetal Neonatal Med 2021; 35:7280-7289. [PMID: 34470117 DOI: 10.1080/14767058.2021.1946787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Since the 50 s of the last century, labor charts have been proposed and appraised as a tool to diagnose labor abnormalities and guide decision-making. The partogram, the most widely adopted form of labor charts, has been endorsed by the world health organization (WHO) since 1994. Nevertheless, recent studies and systematic reviews did not support clinical significance of application of the WHO partogram. These results have led to further studies that investigate modifications to the structure of the partogram, or more recently, to reconstruct new labor charts to improve their clinical efficacy. This guideline appraises current evidence on use of labor charts in management of labor specially in low-resource settings.
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Affiliation(s)
- Sherif A Shazly
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Abdelrahman A Shawki
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Manar M Ahmed
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Fatma A Monib
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Ahmad A Radwan
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Ahmed S Sedik
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Aliaa E Said
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Shimaa S Ali
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Mostafa H Abouzeid
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Esraa G Sayed
- Department of Obstetrics and Gynecology, Assiut School of Medicine, Assiut, Egypt
| | - Ahmed A Nassr
- Department of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Nashwa A Eltaweel
- Department of Obstetrics and Gynecology, University hospitals of Coventry and Warwickshire, UK
| | - Ismet Hortu
- Department of Obstetrics and Gynecology, Ege University School of Medicine, Izmir, Turkey
| | - Rana M Hassan
- Department of Obstetrics and Gynecology, Maternity Hospital, Alexandria, Egypt
| | - Amr S Abdelbadie
- Department of Obstetrics and Gynecology, Aswan University, Aswan, Egypt
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Abstract
In a recent review by Cohen and Friedman, several statistical questions on modeling labor curves were raised. This article illustrates that asking data to fit a preconceived model or letting a sufficiently flexible model fit observed data is the main difference in principles of statistical modeling between the original Friedman curve and our average labor curve. An evidence-based approach to construct a labor curve and establish normal values should allow the statistical model to fit observed data. In addition, the presence of the deceleration phase in the active phase of an average labor curve was questioned. Forcing a deceleration phase to be part of the labor curve may have artificially raised the speed of progression in the active phase with a particularly large impact on earlier labor between 4 and 6 cm. Finally, any labor curve is illustrative and may not be instructive in managing labor because of variations in individual labor pattern and large errors in measuring cervical dilation. With the tools commonly available, it may be more productive to establish a new partogram that takes the physiology of labor and contemporary obstetric population into account.
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Affiliation(s)
- Jun Zhang
- Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - James Troendle
- National Heart Lung Blood Institute, National Institutes of Health, Maryland
| | - Katherine L Grantz
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Maryland
| | - Uma M Reddy
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Maryland
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