Effect of Pethidine Injection on the Duration of Labor and Pregnancy Outcomes: A Retrospective Cohort Study

Background and Objectives: Long and ineffective labor causes hardships for mothers and doctors and increases the rate of cesarean sections and medical comorbidities. Several factors contribute to effective and less painful labor, including maternal age, parity, fetal characteristics, and the medications or procedures that obstetricians use for labor. We aimed to study the factors that affect labor duration and identify those that make labor more effective. Materials and Methods: This retrospective study included 141 patients who underwent normal vaginal deliveries at the Daegu Catholic University Medical Center between April 2013 and April 2022. Among the 141 patients, 44 received pethidine intravenously, 88 received oxytocin intravenously, and 64 received epidural anesthesia. The duration of the active phase and second stage of labor were recorded according to the findings of a manual examination of the cervix and continuous external electronic monitoring. We analyzed maternal and neonatal medical records and performed binomial logistic regression to identify the factors associated with a shorter active phase of labor. The clinical outcomes in mothers and neonates were also evaluated. Results: Among the various clinical factors, multiparity (odds ratio of parity 0.325) and the use of pethidine (odds ratio 2.906) were significantly associated with shortening the active phase of labor to less than 60 min. The use of epidural anesthesia or oxytocin was not significantly associated with reducing the active phase of labor. When patients were divided into two groups based on whether a pethidine injection had been used during labor, the duration of the active phase was shorter in the pethidine injection group than in the control group for both nulliparas and multiparas. No significant differences in the duration of the second stage of labor were observed between the pethidine injection and control groups. There were no significant differences in pregnancy outcomes, including the need for mechanical ventilation of neonates, Apgar scores, neonatal intensive care unit admissions, number of precipitous deliveries, maternal adverse side effects of drugs, or duration of maternal hospitalization between the two groups. Conclusions: Pethidine can be safely administered to women during labor to help reduce the duration of the active phase by promoting dilatation of the cervix and preventing complications that may result from prolonged labor. Pethidine may be helpful, especially for those who cannot receive epidural anesthesia or who cannot afford it. However, large-scale randomized controlled studies are required to evaluate the efficacy and safety of this drug during labor. Furthermore, it would be helpful if various studies were conducted depending on the timing of administration and indications for delivery.

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.

Latent phase duration and associated outcomes: a contemporary, population-based observational study

BACKGROUND

Little is known about the latent phase of labor, including whether its duration influences subsequent labor processes or birth outcomes.

OBJECTIVE

This study aimed to describe the duration of the latent phase of labor from self-report of the onset of painful contractions to a cervical dilation of 5 cm in a large, Swedish population and evaluate the association between the duration of the latent phase of labor and perinatal processes and outcomes that occurred during the active phase of labor, second stage of labor, birth and immediately after delivery, stratified by parity.

STUDY DESIGN

This was a population-based cohort study of 67,267 pregnancies with deliveries between 2008 and 2020 in the Stockholm-Gotland Regions, Sweden. Nulliparous and parous women without a history of cesarean delivery in spontaneous labor with a term (≥37 weeks of gestation), singleton, live, and vertex fetus without major malformations were included. Imputation was used if the notation of the end of the latent phase of labor (ie, cervical dilation of 5 cm) was missing in the partograph. Multivariable logistic regression was used to estimate the association with adjusted odds ratios and 95% confidence intervals, controlling for potential covariates.

RESULTS

Including the time from painful contraction onset to a cervical dilation of 5 cm, the median durations of the latent phase of labor were 16.0 (interquartile range, 10.0-26.6) hours for nulliparous women and 9.4 (interquartile range, 5.9-15.3) hours for multiparous women. The durations of the latent phase of labor beyond the median were associated with increased odds of labor dystocia diagnosis during the first stage active phase or second stage of labor and interventions commonly associated with dystocia (amniotomy, oxytocin augmentation, epidural, and cesarean delivery). The duration of the latent phase of labor of ≥90th percentile vs less than the median in nulliparous women demonstrated an increased risk of adverse neonatal outcomes (Apgar score of <7 at 5 minutes and neonatal intensive care unit admission), chorioamnionitis, and fetal occiput posterior. In multiparous women, longer duration of the latent phase of labor was associated with an increased risk of neonatal intensive care unit admission and chorioamnionitis but was not associated with an Apgar score of <7 at 5 minutes. The duration of the latent phase of labor was not associated with additional markers of maternal risk.

CONCLUSION

The duration of the latent phase of labor in nulliparous women was longer than that of multiparous women at each point of distribution. A longer duration of the latent phase of labor was associated with more frequent dystocia diagnoses and related interventions during the first stage active phase or second stage of labor, including cesarean delivery, nulliparous fetal occiput posterior position, chorioamnionitis, and markers of neonatal morbidity. More research is needed to identify potential mediating paths between the duration of the latent phase of labor and neonatal morbidity.

Intrapartum risk factors associated with pelvic organ prolapse at 6 months postpartum

BACKGROUND

Pregnancy and childbirth are known risk factors associated with the development of pelvic organ prolapse; specific intrapartum risk factors are not well characterized.

OBJECTIVE

This study aimed to determine intrapartum factors associated with increased risk of pelvic organ prolapse identified after delivery.

STUDY DESIGN

A planned secondary analysis of a multicenter randomized clinical trial of delayed vs immediate pushing among nulliparous women at ≥37 weeks of gestation in labor with neuraxial analgesia was conducted at 6 academic and community hospitals in the United States. Intrapartum characteristics were identified, and Pelvic Organ Prolapse Quantification assessments at 6 weeks and 6 months after delivery were performed. The primary outcome was pelvic organ prolapse, defined as stage 2 or greater prolapse using the Pelvic Organ Prolapse Quantification assessment at 6 months. Multivariable logistic regression was used to refine risk estimates while adjusting for randomization group, macrosomia, and maternal age.

RESULTS

Among the 941 women participating in the pelvic floor follow-up, 793 women had Pelvic Organ Prolapse Quantification assessments at 6 weeks with 91 of 793 women (11.5%) demonstrating stage 2 or greater prolapse. Of the 728 women followed up at 6 months, stage 2 or greater prolapse was identified in 58 of 728 women (8.0%). Prostaglandin use for induction of labor was associated with an increased risk at 6 months (adjusted odds ratio, 2.15; 95% confidence interval, 1.18-3.91; P<.01). The length and type (spontaneous vs induced) of the first stage of labor were not significantly associated with stage 2 or greater prolapse. Moreover, increased length of the second stage of labor and duration of pushing were not associated with stage 2 or greater prolapse. After adjusting for confounding factors, cesarean delivery was protective of pelvic organ prolapse at 6 months (adjusted odds ratio, 0.12; 95% confidence interval, 0.02-0.90).

CONCLUSION

The management of the first and second stages of labor, including time length, was not associated with stage 2 or greater prolapse at 6 months. The findings that prostaglandin exposure was associated with increased risk likely were not directly affecting the risk of prolapse but may be surrogates for other labor features that deserve exploration. Cesarean delivery was associated with protection from stage 2 or greater pelvic organ prolapse at 6 months, consistent with previous literature.

Reassessing the duration of each stage of labor and their relation to postpartum hemorrhage in the current Japanese population

AIM

To reassess the normal duration of each stage of labor in a contemporary Japanese cohort, and to determine whether prolongation of each stage of labor increases the rate of postpartum hemorrhage (PPH) in vaginal deliveries.

METHODS

Clinical data of women who delivered at term at 12 facilities between 2012 and 2018 were retrospectively collected. A total of 31 758 women were subdivided into three or four subgroups according to the duration of each stage of labor and parity. Univariate and multivariate logistic regression analyses were performed to estimate crude and adjusted odds ratios (ORs) of PPH (blood loss ≥ 1000 mL) in each subgroup, with women with the shortest durations in each subgroup used as the reference group.

RESULTS

The reference range of each stage of labor was found to be shorter than that previously reported. Women with prolonged second (primiparity, adjusted OR: 1.15-1.78; multiparity, adjusted OR: 1.14-1.74) and third (primiparity, adjusted OR: 1.39-4.95; multiparity, adjusted OR: 1.46-3.80) stages of labor showed an increased risk of PPH, whereas those with prolonged first stage did not. A significantly increased risk of PPH was found both in primiparous and multiparous women with third stages of labor ≥ 5 min.

CONCLUSIONS

The normal duration of each stage of labor in the Japanese population needs to be revised and well-recognized by obstetric care providers. A prolonged third stage of labor was a more important contributing factor to PPH than prolonged first or second stages.

A double-blinded randomized controlled trial on the effects of increased intravenous hydration in nulliparas undergoing induction of labor

BACKGROUND

Rates of labor induction are increasing, raising concerns related to increased healthcare utilization costs. High-dose intravenous fluid (250 cc/h) has been previously demonstrated to shorten the time to delivery in nulliparous individuals in spontaneous labor. Whether or not this relationship exists among individuals undergoing induction of labor is unknown.

OBJECTIVE

Our study aimed to evaluate the effect of high-dose intravenous hydration on time to delivery among nulliparous individuals undergoing induction of labor.

STUDY DESIGN

Nulliparous individuals presenting for induction of labor with a Bishop score of ≤6 (with and without rupture of membranes) were randomized to receive either 125 cc/h or 250 cc/h of normal saline. The primary outcome was length of labor (defined as time from initiation of study fluids to delivery). Both time to overall delivery and vaginal delivery were evaluated. Secondary outcomes included the lengths of each stage of labor, the percentage of individuals delivering within 24 hours, and maternal and neonatal outcomes, including cesarean delivery rate.

RESULTS

A total of 180 individuals meeting inclusion criteria were enrolled and randomized. Baseline demographic characteristics were similar between groups; however, there was a higher incidence of diabetes mellitus in the group receiving 125 cc/h. Average length of labor was similar between groups (27.6 hours in 250 cc/h and 27.8 hours in 125 cc/h), as was the length of each stage of labor. Cox regression analysis did not demonstrate an effect of fluid rate on time to delivery. Neither the admission Bishop score, body mass index, nor other demographic characteristics affected time to delivery or vaginal delivery. There were no differences in maternal or neonatal outcomes, including overall cesarean delivery rate, clinically apparent iatrogenic intraamniotic infection, Apgar scores, need for neonatal phototherapy, or neonatal intensive care unit stay.

CONCLUSION

There were no observed differences in the length of labor or maternal or neonatal outcomes with the administration of an increased rate of intravenous fluids among nulliparous individuals undergoing induction of labor.

Effect of Focusing on Maryam's Flower During the First Stage of the Labor on the Labor Pain, Labor Duration, and Levels of Comfort and Satisfaction

This randomized controlled experimental study was conducted with an intervention group (n = 61) and a control group (n = 63) consisting of primipara pregnant women. The pregnant women in the intervention group were asked to focus their attention on Maryam's flower opening its leaf buds and imagine the labor's progress during the course of their labor. The VAS was administered to each group at specific times (at 4-5 cm, 6-7 cm, 8-9 cm cervical dilatation) to determine their level of labor pain. A statistically significant difference was found between the groups' mean pain scores at 4-5 cm, 6-7 cm, and 8-9 cm cervical dilatation (p < .05). The labor duration of the pregnant women in the intervention group was significantly shorter than that of the pregnant women in the control group (p = .017). The physical comfort level of the intervention group was significantly higher than that of the control group at 8-9 cm cervical dilatation (p = .039).

Time matters-a Swedish cohort study of labor duration and risk of uterine rupture

INTRODUCTION

Uterine rupture is an obstetric emergency associated with maternal and neonatal morbidity. The main risk factor is a prior cesarean section, with rupture occurring in subsequent labor. The aim of this study was to assess the risk of uterine rupture by labor duration and labor management.

MATERIAL AND METHODS

This is a Swedish register-based cohort study of women who underwent labor in 2013-2018 after a primary cesarean section (n = 20 046). Duration of labor was the main exposure, calculated from onset of regular labor contractions and birth; both timepoints were retrieved from electronic medical records for 12 583 labors, 63% of the study population. Uterine rupture was calculated as events per 1000 births at different timepoints during labor. Risk estimates for uterine rupture by labor duration, induction of labor, use of oxytocin and epidural analgesia were calculated using Poisson regression, adjusted for maternal and birth characteristics. Estimates were presented as adjusted rate ratios (ARR) with 95% confidence intervals (CI).

RESULTS

The prevalence of uterine rupture was 1.4% (282/20 046 deliveries). Labor duration was 9.88 hours (95% CI 8.93-10.83) for women with uterine rupture, 8.20 hours (95% CI 8.10-8.31) for women with vaginal delivery, and 10.71 hours (95% CI 10.46-10.97) for women with cesarean section without uterine rupture. Few women (1.0/1000) experienced uterine rupture during the first 3 hours of labor. Uterine rupture occurred in 15.6/1000 births with labor duration over 12 hours. The highest risk for uterine rupture per hour compared with vaginal delivery was observed at 6 hours (ARR 1.20, 95% CI 1.11-1.30). Induction of labor was associated with uterine rupture (ARR 1.54, 95% CI 1.19-1.99), with a particular high risk seen in those induced with prostaglandins and no risk observed with cervical catheter (ARR 1.19, 95% CI 0.83-1.71). Labor augmentation with oxytocin (ARR 1.60, 95% CI 1.25-2.05) and epidural analgesia (ARR 1.63, 95% CI 1.27-2.10) were also associated with uterine rupture.

CONCLUSIONS

Labor duration is an independent factor for uterine rupture among women attempting vaginal delivery after cesarean section. Medical induction and augmentation of labor increase the risk, regardless of maternal and birth characteristics.

Duration of the pushing phase of labor is inversely associated with expression of TNF, IL6, IGF1 and IGF2 in human placenta

OBJECTIVE

Gene expression in placenta differs between vaginal and cesarean deliveries, but the influence of the duration of labor on placental gene expression is incompletely known. Our aim was to investigate associations between duration of labor and expression of some genes involved in growth or inflammation in human placental tissue.

METHODS

Placenta samples (n = 126) were collected after an uncomplicated, singleton pregnancy and term vaginal delivery at Örebro University Hospital, Sweden. Duration of labor was recorded by the midwife in the delivery room. The expression of the following genes was analyzed by RT-qPCR: tumor necrosis factor (TNF), interleukin-6 (IL6), C-X-C motif chemokine ligand 8, toll-like receptor (TLR) 2, TLR4, insulin receptor, insulin-like growth factor (IGF) 1, IGF2, leptin, hepatocyte growth factor (HGF) and HGF receptor (MET). Multivariable linear regression models were used for the evaluation of associations with labor duration adjusting for potential confounding factors. The Benjamini-Hoschberg method was used to correct for multiple testing.

RESULTS

The expression of TNF, IL6, IGF1 and IGF2 was inversely associated with the duration of the pushing phase of labor (B coefficients (95% confidence interval) = -0.150 (-0.277 to -0.023), -0.159 (-0.289 to -0.029), -0.099 (-0.176 to -0.021), and -0.081 (-0.145 to -0.017), respectively).

CONCLUSIONS

Longer duration of pushing is associated with downregulation of the expression of genes in placenta from vaginal deliveries. Future research on gene expression in labored placenta should take into account associations with labor duration and especially the pushing phase. Potential impact of these associations on the mother, the fetus and the new-born infant should also be explored.

Contemporary duration of spontaneous labor and association with maternal characteristics: A French national population-based study

BACKGROUND

The objective of this study was to describe labor duration of women managed with current obstetric practices in a French national population-based cohort and to assess the association of age and BMI on this duration.

METHODS

All women in the French perinatal survey of 2016 with a singleton cephalic fetus, delivering at term after a spontaneous labor were included. Duration of labor was defined as time between admission to the labor ward and birth. Duration of total labor and first and second stage of labor were described. Then, duration of labor was estimated according to maternal age and BMI, using Kaplan-Meier's method and compared with the log-rank test after stratification on parity. Intrapartum cesarean birth was considered as a censoring event. Multivariable modeling was performed using Cox's proportional hazard's method.

RESULTS

Data of 3120 nulliparous and 4385 multiparous women were analyzed. Median labor duration was 6.1 hours ([5th; 95th percentile]) [1.4; 12.6] and 3.1 hours [0.3; 8.5] in nulliparous and multiparous women. Multivariable Cox analysis showed no independent association of maternal age and duration of labor. Nulliparous obese women had significantly lower odds of having a shorter labor than women with a BMI < 25 kg/m² , HR: 0.75; 95% CI [0.64-0.88], but BMI was not associated with labor duration in multiparous women.

CONCLUSIONS

Our study provides important information for both women and care practitioners on what to expect when entering the labor ward. There appears to be little association between maternal characteristics and labor duration, with the exception of BMI in nulliparous women.

Do stress and anxiety in early pregnancy affect the progress of labor: Evidence from the Wirral Child Health and Development Study

Introduction

Despite widespread belief that anxiety causes longer labor, evidence of association is inconsistent. Data gathered as part of a prospective epidemiological longitudinal study were used to investigate associations between antenatal anxiety and pregnancy‐specific stress, and labor progression was assessed by duration and use of augmentation.

Material and methods

Pregnant primiparous women completed measures for anxiety and pregnancy‐specific stress at 20 weeks’ gestation (n = 1145). Birth outcome data were extracted from medical records. Regression analyses and a path analysis assessed associations between antenatal anxiety and pregnancy‐specific stress, and indices of labor progression (labor duration and augmentation).

Results

Anxiety/pregnancy‐specific stress were not directly associated with duration of stage 1 labor (HIGH/LOW anxiety: mean difference = 13.94 minutes, SD = 20.66, 95% CI −26.60 to 54.49, P < .50)/(HIGH/LOW pregnancy‐specific stress: mean difference = 12.05 minutes, SD = 16.09, 95% CI −19.52 to 43.63, P < .45). However, anxiety/pregnancy‐specific stress were associated with epidural use (HIGH/LOW anxiety: 39% vs 31%, P < .042; HIGH/LOW pregnancy‐specific stress: 38% vs 29%, P < .001), which was itself associated with longer labor (mean difference: 158.79 minutes, SD = 16.76, 95% CI 125.89‐191.68, P < .001). Anxiety and pregnancy‐specific stress were associated with increased likelihood of augmentation but these associations were nonsignificant after accounting for epidural, which was itself highly associated with augmentation. However, path analysis indicated an indirect effect linking pregnancy‐specific stress, but not general anxiety, to labor duration and augmentation: elevated pregnancy‐specific stress led to greater use of epidural, which was linked to both increased rates of augmentation, and increased labor duration.

Conclusions

Contrary to general belief, general anxiety and specific pregnancy stress were not directly linked to longer duration of stage one labor. However specific pregnancy stress was associated with epidural use, which in turn was significantly associated with risk of augmentation, and longer stage one labor. Identification of pregnancy‐specific stress could help to identify women for whom psychological interventions could improve birth experience.

The association between longer durations of the latent phase of labor and subsequent perinatal processes and outcomes among midwifery patients

BACKGROUND/OBJECTIVE

To evaluate the association between the duration of the latent phase of labor and subsequent processes and outcomes.

METHODS

Secondary analysis of prospectively collected data among 1,189 women with low-risk pregnancies and spontaneous labor.

RESULTS

Longer latent phase duration was associated with labor dystocia (eg, nulliparous ≥ mean [compared with < mean] aOR 3.95 [2.70-5.79]; multiparous ≥ mean [compared with < mean] aOR 5.45 [3.43-8.65]), interventions to ameliorate dystocia, and epidurals to cope or rest (eg, oxytocin augmentation: nulliparous > 80th% [compared with < 80th%] aOR 6.39 [4.04-10.12]; multiparous ≥ 80th% [compared with < 80th%] aOR 6.35 [3.79-10.64]). Longer latent phase duration was also associated with longer active phase and second stage. There were no associations between latent phase duration and risk for cesarean delivery or postpartum hemorrhage in a practice setting with relatively low rates of primary cesarean. Newborns born to multiparous women with latent phase of labor durations at and beyond the 80th% were more frequently admitted to the NICU (≥80th% [compared with < 80th%] aOR 2.7 [1.22-5.84]); however, two-thirds of these NICU admissions were likely for observation only.

CONCLUSIONS

Longer duration of the spontaneous latent phase of labor among women with low-risk pregnancies may signal longer total labor processes, leading to an increase in diagnosis of dystocia, interventions to manage dystocia, and epidural use. Apart from multiparous neonatal NICU admission, no other maternal or child morbidity outcomes were elevated with longer duration of the latent phase of labor.

Labor patterns in Chinese women in Fuzhou attempting vaginal birth after previous cesarean delivery: a retrospective cohort study

Objective

To investigate the characteristics of labor in Chinese women who successfully have vaginal birth after cesarean section (VBAC).

Methods

A retrospective cohort study was conducted in a hospital with 1000 beds between January 1 2015 and December 31 2017. A total 657 parturients with VBAC were selected. Women were divided into two groups according to previous cesarean section with or without trial of labor. Labor curves were analyzed and interval-censored regression was used to estimate the duration of labor.

Results

The 95th percentile for the first stage of labor in VBAC was 13.03 hours, and labor accelerated after 4 cm of cervical dilation in both groups. The dilation rate in the trial of labor group was superior to that in the non-trial of labor group at 6–10 cm of dilation. After 6 cm, labor accelerated much faster in the trial of labor group than in the non-trial of labor group.

Conclusions

Management of labor in parturients with VBAC whose cervical dilation is >6 cm should be treated differently according to previous cesarean section with or without trial of labor. If there is trial of labor in a previous delivery, the duration of labor should be shortened.

Duration of labor and maternal and neonatal morbidity

BACKGROUND

Labor dystocia has been identified as a contributor to the rising cesarean delivery rate in the United States. Allowing more time for vaginal delivery, while being cognizant of maternal and neonatal outcomes, has been identified as a possible strategy to lower cesarean delivery rates.

OBJECTIVE

This study aimed to characterize the relationship between the duration of active phase and second-stage labor and maternal and neonatal morbidity.

STUDY DESIGN

We present a secondary analysis of the Consortium on Safe Labor project. From labors of 66,940 nonanomalous nulliparous term singleton vertex gestations, we excluded labors for which active phase (≥6 cm dilation) or second stage durations could not be calculated and from sites that did not report determinants of morbidity. For each duration of active phase or second stage labor (grouped in 1-hour increments), the adjusted maternal and neonatal composite morbidity was estimated by and compared with the morbidity associated with a duration <1 hour total and a duration of 1 hour shorter.

RESULTS

After exclusions, 48,144 deliveries remained. In adjusted models, compared with labor durations <1 hour total, maternal composite morbidity was significantly higher across active phase and second stage durations (both P<.001); neonatal composite morbidity was higher across the second stage (P<.001), but not active phase (P=.07) duration. These relationships appear linear with no apparent inflection point, and morbidity increases more rapidly. When compared with labor durations 1 hour shorter, significant differences persisted in maternal and neonatal composite morbidity in second stage labor only through 4 and 3 hours, respectively.

CONCLUSION

Maternal and neonatal composite morbidity is greater with longer durations of active and second stage labor; however, no clear cutoff point was determined to suggest truncation of either stage of labor for reasons of morbidity. In addition, incrementally higher morbidities that were noted vs duration <1 hour total were obscured when comparison was made with labors 1 hour shorter, which suggests that focusing on short differences in duration of labor may mask important underlying trends.

Factors affecting labor duration in Chinese pregnant women

The aim of the study was to explore the role of parity, maternal age, medical interventions, and birth weight with respect to labor duration and cervical dilation.A total of 1601 pregnant women who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome were reviewed. The retrospective study was conducted in patients from West China Second University Hospital of Sichuan University during June 2008 to June 2013.There were 1367 nulliparous women and 234 multiparous women analyzed. The first stage (8.3 ± 3.8 vs 5.0 ± 2.6 hours), latent phase (5.1 ± 3.2 vs 3.5 ± 2.4 hours), active phase (3.2 ± 1.8 vs 1.5 ± 1.0 hours), second stage (44 ± 31 vs 18 ± 14 minutes), and total stage of labor (9.1 ± 3.9 vs 5.4 ± 2.6 hours) were all longer in nulliparous than in multipara women (all P < .05); but no significant difference in the third stage of labor (both 7 ± 4 minutes). In nulliparous women, the average time of first stage of labor increased by 58.257, 171.443, and 56.581 minutes due to artificial rupture of membranes, labor analgesia, and birth weight increased by 1 kg, respectively, but it decreased to 63.592 minutes by oxytocin usage, and the difference was significant. The average time of first stage of labor in nulliparous women aged from 26 to 30 years increased by 2.356 minutes compared to one in 20 to 26 years, but it increased by 1.802 minutes to the one in 30 to 39 years, compared to 20 to 26 years and the difference was not significant. The results were basically similar after multipara women were included.Labor was significantly shorter in multiparous women than that in nulliparous women. Increased birth weight significantly increased in the length of the active phase and the second stage among nulliparous women. The increase of age, artificial rupture of membranes, labor analgesia, and the increase of birth weight tends to increase the time of first stage of labor and total labor duration, whereas oxytocin could shorten it.

Length of the second stage of labor and preterm delivery risk in the subsequent pregnancy

BACKGROUND

Cervical injury is regarded as an important risk factor for preterm delivery. A prolonged second stage of labor may increase the risk of cervical injury that, in turn, may be associated with increased risk of spontaneous preterm delivery in the subsequent pregnancy.

OBJECTIVE

We sought to evaluate whether the duration of the second stage of labor in a term primiparous singleton delivery is associated with an increased risk of singleton spontaneous preterm delivery (<37 weeks) in the second pregnancy.

STUDY DESIGN

We carried out a retrospective cohort analysis of women with 2 consecutive pregnancies: a first term (≥37 weeks) delivery and second birth. Data were derived from a single institution's prospectively collected obstetrical database from January 2005 through January 2015. Duration of the second stage of labor was examined as a continuous variable, modeled based on nonparametric restricted cubic regression spline with 4 degrees of freedom. Second-stage duration was also examined as short (<30 minutes), normal (30-179 minutes), and prolonged, defined as ≥180 minutes. The association between the duration of the second stage of labor in the first term pregnancy and the risk for spontaneous preterm delivery in the second pregnancy was evaluated before and after adjusting for potential confounders based on the Cox proportional hazards regression model. Associations were expressed based on the adjusted hazard ratio and 95% confidence interval.

RESULTS

In all, 6715 women met inclusion criteria. The hazard of spontaneous preterm delivery in the second pregnancy trended higher with both shorter and longer second-stage labors. The length of the second stage of labor in the first term delivery was categorized as short (<30 minutes) in 1749 (26.0%), normal (30-179 minutes) in 4551 (67.8%), and prolonged (≥180 minutes), in 415 (6.2%) women. Of these 6715 women with a first term delivery, 4.2% (n = 279) delivered spontaneously preterm in the second pregnancy. The risks of spontaneous preterm delivery among women with prolonged (≥180 minutes) second stage of labor and normal labor duration (30-179 minutes) were 5.4% (n = 22) and 3.5% (n = 158), respectively (adjusted hazard ratio, 1.81; 95% confidence interval, 1.15-2.84). This increased risk for prolonged second stage of labor was primarily seen among women who underwent a cesarean (hazard ratio, 3.38; 95% confidence interval, 1.09-10.49), but was imprecise among women who delivered vaginally (hazard ratio, 1.52; 95% confidence interval, 0.62-3.74). The risk of spontaneous preterm delivery among women with short second stage of labor (<30 minutes) in their first term pregnancy was 5.8% (n = 99; hazard ratio, 1.28; 95% confidence interval, 0.99-1.67).

CONCLUSION

The risk of spontaneous preterm delivery in the second pregnancy was increased in women with a prolonged (≥180 minutes) second stage in the first term pregnancy. This risk was even greater among women who were delivered by cesarean in the first pregnancy.

Effects of combined spinal-epidural analgesia on first stage of labor: a cohort study

Background: Neuraxial anesthesia is considered as the gold standard in the control labor of pain. Its variants are epidural analgesia and combined spinal-epidural analgesia. Few studies, as yet, have investigated the duration of labor as a primary outcome. Some authors have suggested that combined spinal-epidural analgesia may reduce labor duration but at the moment the benefit of shortening labor is uncertain. The main aim of this study was to compare combined spinal-epidural with epidural analgesia in terms of their effect on duration of stage I labor, maternal, and neonatal outcomes. Methods: A prospective cohort study was conducted. Parturients who requested analgesia at cervical dilatation <6 cm were included. Analgesia was either epidural with low concentration levobupivacaine or combined spinal epidural with subarachnoid sufentanil. The primary outcome was the length of stage I labor. Onset and quality of analgesia, mode of delivery, effects on uterine activity and use of oxytocin, fetal heart rate abnormalities and uterine hyperkinesia, maternal, and neonatal complications were also considered. Results: We enrolled 400 patients: 176 in the combined spinal-epidural group and 224 in the epidural group. Patients in the two treatment groups were similar with regard to demographic characteristics, parity, and incidence of obstetric comorbidities, labor induction, oxytocin infusion, Bishop score, and Visual Analogue Score (VAS) at analgesia request. Duration of stage I labor did not differ, at 195 (120-300) minutes for both the groups (p = .7). Combined spinal-epidural was associated with less reduction in uterine contractility after initial administration: 15.34 versus 39.73%, (p < .001) and with delayed need for oxytocin, at dilations of 7 ± 2.5 cm versus 6. ± 2.7, (p = .002). Onset of analgesia was quicker for combined spinal-epidural analgesia: 31 versus 20%, with VAS <4 after 5 minutes, (p < .001); and lower VAS scores after initial analgesia administration. No differences were found in the other outcomes. Conclusions: Combined spinal-epidural with subarachnoid sufentanil may not reduce the duration of stage I labor, but in our study it appeared to affect uterine contractility less. It also had a more rapid onset and was more effective, without any concomitant increase in maternal or neonatal complications.

Induction of labor in women with a history of fast labor

OBJECTIVE

History of fast labor is currently subjectively defined and inductions for non-medical indications are becoming restricted. We hypothesized that women induced for a history of fast labor do not have faster previous labors and do not deliver more quickly.

METHODS

A retrospective case-control cohort design studied multiparas undergoing elective induction at one high risk center. Outcomes of dyads electively induced for a history of previous fast labor indication (PFast) were compared to controls with a psychosocial indication.

RESULTS

A total of 612 elective inductions with 1074 previous deliveries were evaluated: 81 (13%) PFast and 531 (87%) control. PFast had faster previous labors (median 5.5 h, IQR: 4.5-6) versus. control (10 h, IQR: 9-10.5; p < 0.001). Subsequent delivery time from start to expulsion was shorter for PFast (median 7 h, IQR: 5-9, p < 0.001) than controls with and without a previous labor <5.5 h (8.6 h, IQR: 6-14 and 9.5 h, IQR: 7-15, respectively). PFast were less likely to have a serious maternal complication. Neonatal complications were similar.

CONCLUSIONS

Patients induced for a history of fast labor do have faster previous labors, suggesting a significant history of fast labor can be defined as <5.5 h. These women deliver more quickly and with lower morbidity than controls when subsequently induced, therefore the benefit may warrant the risk for a select number of women with a history of a prior labor length <5.5 h.

A comparison of maternal and neonatal outcomes between water immersion during labor and conventional labor and delivery

BACKGROUND

Water immersion during the first stage of labor can reduce the length of the first stage and epidural/spinal analgesia use; however, there is limited information regarding other outcomes. Our purpose was to compare maternal and neonatal outcomes of women who underwent water immersion during the first stage of labor with those who underwent conventional labor and delivery.

METHODS

Healthy primipara with singleton pregnancies and cephalic presentation were included in the study. Patients were allowed to choose water immersion during labor or conventional labor and delivery. For water immersion, the water temperature was maintained at 35-38°C and subjects left the tub on complete cervical dilatation. A visual analogue scale (VAS) was used to assess pain during labor. Other outcome measures included duration of labor, type of delivery, blood loss, pelvic floor dysfunction and symptoms of stress urinary incontinence (SUI) at 42 days after delivery, infant Apgar scores, and need for transfer of the infant to the neonatal intensive care unit.

RESULTS

Thirty eight subjects (mean age, 28.66 ± 3.08 y) received water immersion and 70 (mean age, 27.89 ± 2.99 y) underwent conventional labor and delivery. There were no differences in maternal height, weight, age, gestational age, gravidity, and newborn weight between the groups (all, p>0.05). VAS pain scores were significantly greater in the conventional labor group at 30 min and 60 min after a cervical dilatation of 3 cm (30 min: 10 [9, 10] vs. 6 [5, 8]; 60 min: 10 [10, 10] vs. 7 [6, 8], respectively, both, p<0.001). The duration of labor and postpartum bleeding were similar between the groups (all, p>0.05). The cesarean section rate was higher in the conventional labor group (32.9% vs. 13.2%, p=0.026). The 1-minute and 5-minute Apgar scores were similar between the groups. Maternal and neonatal culture results were similar between the groups. SUI symptoms at 42 days after delivery was significantly higher in the conventional labor group (25.5% vs. 6.1%, respectively, p=0.035).

CONCLUSIONS

Water immersion can reduce labor pain, and is associated with a lower rate of cesarean delivery and SUI symptoms at 42 days.

Changes in labor patterns over 50 years

OBJECTIVE

The objective of the study was to examine differences in labor patterns in a modern cohort compared with the 1960s in the United States.

STUDY DESIGN

Data from pregnancies at term, in spontaneous labor, with cephalic, singleton fetuses were compared between the Collaborative Perinatal Project (CPP, n = 39,491 delivering 1959-1966) and the Consortium on Safe Labor (CSL; n = 98,359 delivering 2002-2008).

RESULTS

Compared with the CPP, women in the CSL were older (26.8 ± 6.0 vs 24.1 ± 6.0 years), heavier (body mass index 29.9 ± 5.0 vs 26.3 ± 4.1 kg/m(2)), had higher epidural (55% vs 4%) and oxytocin use (31% vs 12%), and cesarean delivery (12% vs 3%). First stage of labor in the CSL was longer by a median of 2.6 hours in nulliparas and 2.0 hours in multiparas, even after adjusting for maternal and pregnancy characteristics, suggesting that the prolonged labor is mostly due to changes in practice patterns.

CONCLUSION

Labor is longer in the modern obstetrical cohort. The benefit of extensive interventions needs further evaluation.