Reevaluation of Friedman's Labor Curve: A Pilot Study

New insights on labor progression: a systematic review

The past 20 years witnessed an invigoration of research on labor progression and a change of thinking regarding normal labor. New evidence is emerging, and more advanced statistical methods are applied to labor progression analyses. Given the wide variations in the onset of active labor and the pattern of labor progression, there is an emerging consensus that the definition of abnormal labor may not be related to an idealized or average labor curve. Alternative approaches to guide labor management have been proposed; for example, using an upper limit of a distribution of labor duration to define abnormally slow labor. Nonetheless, the methods of labor assessment are still primitive and subject to error; more objective measures and more advanced instruments are needed to identify the onset of active labor, monitor labor progression, and define when labor duration is associated with maternal/child risk. Cervical dilation alone may be insufficient to define active labor, and incorporating more physical and biochemical measures may improve accuracy of diagnosing active labor onset and progression. Because the association between duration of labor and perinatal outcomes is rather complex and influenced by various underlying and iatrogenic conditions, future research must carefully explore how to integrate statistical cut-points with clinical outcomes to reach a practical definition of labor abnormalities. Finally, research regarding the complex labor process may benefit from new approaches, such as machine learning technologies and artificial intelligence to improve the predictability of successful vaginal delivery with normal perinatal outcomes.

Middle-East OBGYN graduate education (MOGGE) foundation practice guidelines: use of labor charts in management of labor. Practice guideline no. 04-O-21

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.

Simulation model of the relationship between cesarean section rates and labor duration

Cesarean delivery is the most common major abdominal surgery in many parts of the world, and it accounts for nearly one-third of births in the United States. For a patient who requires a C-section, allowing prolonged labor is not recommended because of the increased risk of infection. However, for a patient who is capable of a successful vaginal delivery, performing an unnecessary C-section can have a substantial adverse impact on the patient's future health. We develop two stochastic simulation models of the delivery process for women in labor; and our objectives are (i) to represent the natural progression of labor and thereby gain insights concerning the duration of labor as it depends on the dilation state for induced, augmented, and spontaneous labors; and (ii) to evaluate the Friedman curve and other labor-progression rules, including their impact on the C-section rate and on the rates of maternal and fetal complications. To use a shifted lognormal distribution for modeling the duration of labor in each dilation state and for each type of labor, we formulate a percentile-matching procedure that requires three estimated quantiles of each distribution as reported in the literature. Based on results generated by both simulation models, we concluded that for singleton births by nulliparous women with no prior complications, labor duration longer than two hours (i.e., the time limit for labor arrest based on the Friedman curve) should be allowed in each dilation state; furthermore, the allowed labor duration should be a function of dilation state.

Efficacy of warm showers on labor pain and birth experiences during the first labor stage

OBJECTIVE

To determine the efficacy of warm showers on parturition pain and the birth experiences of women during the first stage of labor.

DESIGN

Randomized controlled trial (RCT).

SETTING/PARTICIPANTS

The study was conducted from July 10, 2010 to January 12, 2011 in the maternity ward of a Taipei City regional teaching hospital, site of approximately 220 to 250 births per month. Ninety-two expectant mothers were recruited (recruitment rate: 70.8%) and allocated by block randomization into the two arms of the study. In total, 80 women completed the trial: 41 in the control group and 39 in the experimental group.

METHODS

Participants in the experimental group received warm shower bath interventions. Each shower lasted 20 minutes. After a 5-minute full body or lower back shower, participants could spend 15 minutes directing shower water toward any body region that felt most comfortable. Facilities allowed participants to stand and sit as desired. Water was constantly monitored and maintained at a temperature of 37°C. Participants in the control group received standard childbirth care.

RESULTS

Labor pain and the birth experience were assessed using the Visual Analogue Scale for Pain (VASP) and the Labour Agentry Scale, respectively. After adjusting for demographic and obstetric data, experimental-group women who participated in warm showers reported significantly lower VASP scores at 4-cm and 7-cm cervical dilations, and higher birth experiences than the control group.

CONCLUSION

Apart from the positive physical hygiene effects, warm showers are a cost-effective, convenient, easy-to-deploy, nonpharmacological approach to pain reduction. This intervention helps women in labor to participate fully in the birthing process, earn continuous caregiver support, feel cared for and comforted, and have a more positive overall experience.

Length of the first stage of labor and associated perinatal outcomes in nulliparous women

OBJECTIVE

To estimate whether length of the first stage of labor is associated with adverse maternal and neonatal outcomes.

METHODS

This is a retrospective cohort study of nulliparous women with term, singleton gestations delivered in one academic center between 1990 and 2008. The length of the first stage was stratified into three subgroups: less than the 5th percentile, 5th to 95th percentile, and greater than the 95th percentile. Maternal and neonatal outcomes were compared using the χ test. Multivariable logistic regression models were used to control for confounders.

RESULTS

Of the 10,661 nulliparous women meeting study criteria, the median (50th percentile) length of the first stage was 10.5 hours. Compared with women with a first stage between 2.8 and 30 hours (5th to 95th percentile thresholds), the risk of cesarean delivery was higher (6.1% compared with 13.5%; adjusted odds ratio [OR], 2.28, 95% confidence interval [CI], 1.92-2.72) in women with a first stage longer than 30 hours (greater than the 95th percentile). These women also had higher odds of chorioamnionitis (12.5% compared with 23.5%; adjusted OR, 1.58; 95% CI, 1.25-1.98) and neonatal admission to the neonatal intensive care unit (4.7% compared with 9.8%; adjusted OR, 1.53; 95% CI, 1.18-1.97) but no other associated adverse neonatal outcomes.

CONCLUSION

Women with a prolonged first stage of labor have higher odds of cesarean delivery and chorioamnionitis, but their neonates are not at risk of increased morbidity.

LEVEL OF EVIDENCE

II.

Labor analgesia for patients with preterm premature rupture of membranes

OBJECTIVE

Cervical examination is relatively contraindicated in women with preterm premature rupture of membranes (PPROM), limiting our ability to determine the onset of labor by traditional definition (contractions with cervical change). We sought to determine whether two maternal requests for analgesia within 3 h predicted delivery within 24 h to allow appropriate epidural placement.

STUDY DESIGN

We performed a retrospective chart review of all patients with PPROM for a period of 18 months. Our primary outcome was the percentage of women with PPROM (<34 weeks) who delivered within 24 h from the second analgesia request.

RESULT

Among women with PPROM, 63% delivered within 24 h from their second request for analgesia and 98% delivered within 48 h.

CONCLUSION

Two medication requests within 3 h for regular, painful contractions can be used as an indicator of onset of labor in women with PPROM to allow for labor analgesia.

Evaluation of the labor curve in nulliparous Japanese women

OBJECTIVE

We sought to compare Japanese nulliparous labor progression with Friedman's classic 1955 curve and Zhang's 2002 curve.

STUDY DESIGN

We developed a labor curve using retrospective record reviews of 2369 Japanese nulliparas, at term, spontaneous labor onset and singleton vertex deliveries of normal birth weight infants.

RESULTS

The new Japanese Suzuki-Horiuchi labor curve with slower cervical dilation in the active phase was like Zhang's and differed from Friedman's curve. Labor length was approximately 5 hours occurring between 4-10 cm compared with Friedman's 2.5 hours and Zhang's 5.5 hours. Even at 10-cm dilation, labor lasted >2 hours at the 95th percentile of time interval.

CONCLUSION

Similar to Zhang's curve, the Suzuki-Horiuchi curve was smooth and more gradually sloped than Friedman's curve. Appraise "arrested or protracted labor" with these slower labor curves in mind using Friedman's curve cautiously.

The evidence supporting nursing management of labor

Although nursing practice is responsive to research findings, the practice site in which a nurse works has an impact on the ability to incorporate research changes into practice in a timely fashion. This review of the evidence base for nursing management of labor care focuses on care that typically falls within the nurses' domain and highlights the evidence in five areas in which there is research on patient preferences. These include management of admission and of progression during the first stage of labor, fetal monitoring, care and comfort practices during labor, and the management of second-stage labor. Directions for achieving progress toward practice change are highlighted.