Defining and Managing Normal and Abnormal First Stage of Labor

New definitions, old complications: The association between duration of transition from latent to active labor and adverse obstetrical outcomes

OBJECTIVE

To explore the relationship between the duration of transition from latent to active labor and various obstetric, maternal, fetal, and neonatal outcomes.

METHODS

A retrospective cohort study was conducted on term, singleton deliveries at Soroka University Medical Center from 2013 to 2018. Data were extracted from electronic medical records. The exposure variable was defined as prolonged transition, which was itself defined as the upper 10th centile of dilation duration from 4 to 6 cm. Clinical and demographic characteristics were compared using χ2 test. Multivariate logistic regression was used to estimate the contribution of a prolonged transition with each adverse outcome adjusting for potential confounders.

RESULTS

In all, 12 104 deliveries met the inclusion criteria. The mean ± standard deviation of duration of dilation from 4 to 6 cm was 03:07:58 ± 03:03:42 (hours:minutes:seconds). Progress curves varied significantly among patients with different obstetrical and demographic characteristics. Prolonged transition was significantly linked to an increased risk of cesarean delivery (adjusted odds raito 2.607, 95% confidence interval 2.171-3.130, area under the curve 0.689) and higher rates of maternal and neonatal morbidity.

CONCLUSIONS

Patients experiencing transition phases exceeding the 90th centile faced an elevated risk of cesarean delivery and postpartum complications. Future studies should focus on interventions during the transition phase to improve pregnancy outcomes and enhance patient safety.

Host-microbiome interactions in distinct subsets of preterm labor and birth

Preterm birth, the leading cause of perinatal morbidity, often follows premature labor, a syndrome whose prevention remains a challenge. To better understand the relationship between premature labor and host-microbiome interactions, we conducted a mechanistic investigation using three preterm birth models. We report that intra-amniotic delivery of LPS triggers inflammatory responses in the amniotic cavity and cervico-vaginal microenvironment, causing vaginal microbiome changes and signs of active labor. Intra-amniotic IL-1α delivery causes a moderate inflammatory response in the amniotic cavity but increasing inflammation in the cervico-vaginal space, leading to vaginal microbiome disruption and signs of active labor. Conversely, progesterone action blockade by RU-486 triggers local immune responses accompanying signs of active labor without altering the vaginal microbiome. Preterm labor facilitates ascension of cervico-vaginal bacteria into the amniotic cavity, regardless of stimulus. This study provides compelling mechanistic insights into the dynamic host-microbiome interactions within the cervico-vaginal microenvironment that accompany premature labor and birth.

The effect of ultrasonographically measured fetal adipose tissue components on labor

AIM

To investigate whether increased fetal adiposity diagnosed ultrasonographical is associated with labor dystocia, and increased risk of operative delivery.

METHOD

This was a prospective study and included 400 pregnant women between 37 and 41 weeks of gestation. In addition to standard ultrasonographic measurements, we evaluated fetal soft tissue thickness before delivery. We also recorded data on delivery method, shoulder dystocia, fetal birthweight and labor duration. We considered the period between 6 and 10 cm cervical opening as the active phase, and the period from full dilation to birth as the second stage.

RESULTS

While the vaginal delivery rate was 77.3%, a cesarean was performed in 22.7% of pregnant women. We found a positive correlation between fetal adipose tissue components and durations of the active phase and second-stage labor and the baby's birthweight. Also, we examined and determined that cesarean section and labor dystocia increased as the fetus adipose tissue thickness increased. We investigated the effect of parameters on the study results with logistic regression analysis and possible threshold values with receiver operating characteristics analysis.

CONCLUSION

Our study evaluated the fetal adipose tissue complex during delivery was significant in terms of labor dystocia and operative delivery. We think it may be a guide for future studies in the literature.

The 90% Effective Dose of Sufentanil for Epidural Analgesia in the Early First Stage of Labor: A Double-blind, Sequential Dose-Finding Study

PURPOSE

Epidural analgesia in the latent phase of the first stage of labor has been recognized and accepted by anesthesiologists worldwide. However, there is no unified consensus on the exact dosage of sufentanil with the combination of ropivacaine in the induction of epidural analgesia in the early first stage of labor. In this sequential dose-finding study, the 90% effective dose (ED₉₀) of sufentanil for epidural administration in the early first stage of labor was estimated to minimize the adverse effects of using higher doses.

METHODS

Forty parturients with cervical dilatation of 2 to 4 cm who requested epidural analgesia were enrolled in this study. Parturients received 15 mL of a combination of ropivacaine 13 mg and the test dose of sufentanil. The initial dose of sufentanil in epidural administration was 1 μg, and the dose of sufentanil for the next parturient was based on the response of the preceding participant as per a biased coin up-and-down design. The primary outcome was the dose of sufentanil that resulted in successful epidural administration by maintaining the parturients' visual analog scale scores at ≤30 mm in the first 15, 30, and 45 minutes of induction. The ED₉₀ and 95% CIs were estimated using isotonic regression methods and bootstrapping.

FINDINGS

The estimated ED₉₀ of sufentanil in epidural administration in the early first stage of labor was 1.91 μg (95% CI, 1.82-2.35 μg) in this sequential dose-finding study.

IMPLICATIONS

Sufentanil at a dosage of 2 μg is recommended for the administration of epidural analgesia in parturients in the early first stage of labor. ChiCTR.org.cn identifier: 1900021683.

The impact of stage of labor on adverse maternal and neonatal outcomes in multiparous women: a retrospective cohort study

BACKGROUND

The correlation between stage of labor and adverse delivery outcomes has been widely studied. Most of studies focused on nulliparous women, it was not very clear what impact the stage of labor duration had on multiparous women.

METHODS

A retrospective cohort study was conducted among all the multiparous women of cephalic, term, singleton births, who planned vaginal delivery. The total stage of labor covered the first stage and the second stage in this study, and they were divided into subgroups. Adverse maternal outcomes were defined as referral cesarean delivery, instrumental delivery, postpartum hemorrhage, perineal laceration (III and IV degree), hospitalization stay ≥90th, and adverse neonatal outcomes as NICU, shoulder dystocia, Apgar score ≤ 7(5 min), neonatal resuscitation, assisted ventilation required immediately after delivery.

RESULTS

There were 7109 parturients included in this study. The duration of first stage was 6.2(3.6-10.0) hours, the second stage was 0.3(0.2-0.7) hour, the total stage was 6.9(4.1-10.7) hours in multiparous women. At the first stage, the rates of overall adverse outcome were 21, 23.4, 28.8, 35.5, 38.4% in subgroups < 6 h, 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥24 h, which increased significantly (X² = 57.64, P < 0.001), and ARR (95% CI) were 1.10 (0.92,1.31), 1.33 (1.04,1.70), 1.80 (1.21,2.68), 2.57 (1.60,4.15) compared with subgroup < 6 h (ARR = 1); At the second stage, the rates of overall adverse outcome were 20.0, 30.7, 38.5, 61.2, 69.6% in subgroups < 1 h, 1-1.9 h, 2-2.9 h, 3-3.9 h, ≥4 h (X² = 349.70, P < 0.001), and ARR (95% CI) were 1.89 (1.50, 2.39), 2.22 (1.55, 3.18), 10.64 (6.09, 18.59), 11.75 (6.55, 21.08) compared with subgroup < 1 h (ARR = 1)). At the total stage, the rates of overall adverse outcome were 21.5, 30.8, 42.4% in subgroups < 12 h, 12-23.9 h, ≥24 h (X² = 84.90, P < 0.001), and ARR (95% CI) were 1.41 (1.16,1.72), 3.17 (2.10,4.80) compared with subgroup < 12 h (ARR = 1).

CONCLUSIONS

The prolonged stage of labor may lead to increased adverse outcomes in multiparous women, it was an independent risk factor of adverse maternal and neonatal outcomes.

Intrauterine versus external tocodynamometry in monitoring labour: a randomised controlled clinical trial

OBJECTIVE

To investigate whether the use of intrauterine tocodynamometry versus external tocodynamometry (IT versus ET) during labour reduces operative deliveries and improves newborn outcome. As IT provides more accurate information on labour contractions, the hypothesis was that it may more appropriately guide oxytocin use than ET.

DESIGN

Randomised controlled trial.

SETTING

Two labour wards, in a university tertiary hospital and a central hospital.

POPULATION

A total of 1504 parturients with singleton pregnancies, gestational age ≥37 weeks and fetus in cephalic position: 269 women with uterine scars, 889 nulliparas and 346 parous women with oxytocin augmentation.

METHODS

Participants underwent IT (n = 736) or ET (n = 768) during the active first stage of labour.

MAIN OUTCOME MEASURES

Primary outcome: rate of operative deliveries.

SECONDARY OUTCOMES

duration of labour, amount of oxytocin given, adverse neonatal outcomes.

RESULTS

Operative delivery rates were 26.9% (IT) and 25.9% (ET) (odds ratio 1.05, 95% CI 0.84-1.32, P = 0.663). The ET to IT conversion rate was 31%. We found no differences in secondary outcomes (IT versus ET). IT reduced oxytocin use during labours with signs of fetal distress, and trial of labour after caesarean section.

CONCLUSIONS

IT did not reduce the rate of operative deliveries, use of oxytocin, or adverse neonatal outcomes, and it did not shorten labour duration.

TWEETABLE ABSTRACT

IT (versus ET) reduced oxytocin use in high-risk labours but did not influence operative delivery rate or adverse neonatal outcomes.

Describing latent phase duration and associated characteristics among 1281 low-risk women in spontaneous labor

BACKGROUND

Recent research suggests that latent phase of labor may terminate at 6 rather than 4 centimeters of cervical dilation. The objectives of this study were to: (a) characterize duration of the latent phase of labor among term, low-risk, United States women in spontaneous labor using the women's self-identified onset; and (b) quantify associations between demographic and maternal/newborn health characteristics and the duration of the latent phase.

METHODS

This prospective study (n = 1281) described the duration of the latent phase of labor in hours, stratified by parity at the mean, median, and 80th, 90th, and 95th percentiles. The duration of the latent phase was compared for each characteristic using t tests or Wilcoxon rank-sum tests and regression models that controlled for confounders.

RESULTS

In this sample of predominantly white, healthy women, duration of the latent phase of labor was longer than described in previous studies: The median duration was 9.0 hours and mean duration was 11.8 hours in nulliparous women. The median duration was 6.8 hours and mean duration was 9.3 hours in multiparous women. Among nulliparous women, longer duration was seen in women whose fetus was in a malposition. Among multiparous women, longer durations were noted in women with chorioamnionitis and those who gave birth between 41 and 41 + 6 weeks' gestation (vs between 40 and 40 + 6 weeks' gestation).

CONCLUSIONS

The latent phase of labor may be longer than previously estimated. Contemporary estimates of latent phase of labor duration will help women and providers accurately anticipate, prepare, and cope during spontaneous labor.

The Labor Progression Study: The use of oxytocin augmentation during labor following Zhang's guideline and the WHO partograph in a cluster randomized trial

INTRODUCTION

This study aims to investigate the use of oxytocin augmentation during labor in nulliparous women following Zhang's guideline or the WHO partograph.

MATERIAL AND METHODS

This is a secondary analysis of a cluster randomized controlled trial in 14 birth-care units in Norway, randomly assigned to either the intervention group, which followed Zhang's guideline, or to the control group, which followed the WHO partograph, for labor progression. The participants were nulliparous women who had a singleton full-term fetus in a cephalic presentation and spontaneous onset of labor, denoted as group 1 in the Ten Group Classification System.

RESULTS

Between December 2014 and January 2017, 7277 participants were included. A total of 3219 women (44%) received augmentation with oxytocin during labor. Oxytocin was used in 1658 (42%) women in the Zhang group compared with 1561 (47%) women in the WHO group. The adjusted relative risk for augmentation with oxytocin was 0.98 (95% CI 0.84-1.15; P = .8) in the Zhang vs WHO group, with an adjusted risk difference of -0.8% (95% CI -7.8 to 6.1). The participants in the Zhang group were less likely to be augmented with oxytocin before reaching 6 cm of cervical dilatation (24%) compared with participants in the WHO group (28%), with an adjusted relative risk of 0.84 (95% CI 0.75-0.94; P = .003). Oxytocin was administered for almost 20 min longer in the Zhang group than in the WHO group, with an adjusted mean difference of 17.9 min (95% CI 2.7-33.1; P = .021). In addition, 19% of the women in the Zhang group and 23% in the WHO group received augmentation with oxytocin without being diagnosed with labor dystocia.

CONCLUSIONS

Although no significant difference in the proportion of oxytocin augmentation was observed between the 2 study groups, there were differences in how oxytocin was used. Women in the Zhang group were less likely to receive oxytocin augmentation before 6 cm of cervical dilatation. The duration of augmentation with oxytocin was longer in the Zhang group than in the WHO group.

Implementation of the WHO manual for Robson classification: an example from Sri Lanka using a local database for developing quality improvement recommendations

OBJECTIVES

This study aimed at describing the use of a prospective database on hospital deliveries for analysing caesarean section (CS) practices according to the WHO manual for Robson classification, and for developing recommendations for improving the quality of care (QoC).

DESIGN

Observational study.

SETTING

University Obstetric Unit at De Soysa Hospital for Women, the largest maternity unit in Sri Lanka.

DATA COLLECTION AND ANALYSIS

For each childbirth, 150 variables were routinely collected in a standardised form and entered into a database. Data were routinely monitored for ensuring quality. Information on deliveries occurring from July 2015 to June 2017 were analysed according the WHO Robson classification manual. Findings were discussed internally to develop quality improvement recommendations.

RESULTS

7504 women delivered in the hospital during the study period and at least one maternal or fetal pathological condition was reported in 2845 (37.9%). The CS rate was 30.0%, with 11.9% CS being performed prelabour. According to the Robson classification, Group 3 and Group 1 were the most represented groups (27.0% and 23.1% of population, respectively). The major contributors to the CS rate were group 5 (29.6%), group 1 (14.0%), group 2a (13.3%) and group 10 (11.5%). The most commonly reported indications for CS included abnormal cardiotocography/suspected fetal distress, past CS and failed progress of labour or failed induction. These suggested the need for further discussion on CS practices. Overall, 18 recommendations were agreed on. Besides updating protocols and hands-on training, activities agreed on included monitoring and supervision, criterion-based audits, risk management meetings and appropriate information for patients, and recommendations to further improve the quality of data.

CONCLUSIONS

This study provides an example on how the WHO manual for Robson classification can be used in an action-oriented manner for developing recommendations for improving the QoC, and the quality of data collected.