Anal incontinence after a prolonged second stage of labor in primiparous women

Inconsistent definitions of prolonged labor in international literature: a scoping review

Objective

Prolonged labor is the commonest indication for intrapartum cesarean section, but definitions are inconsistent and some common definitions were recently found to overestimate the speed of physiological labor. The objective of this review is to establish an overview of synonyms and definitions used in the literature for prolonged labor, separated into first and second stages, and establish types of definitions used.

Data sources

A systematic search was conducted in PubMed, Embase, Web of Science, Cochrane Library, Emcare, and Academic Search Premier.

Study eligibility criteria

All articles in English that (1) attempted to define prolonged labor, (2) included a definition of prolonged labor, or (3) included any synonym for prolonged labor, were included.

Methods

Data on study design, year of publication, country or region of origin, synonyms used, definition of prolonged first and/or second stage, and origin of provided definition (if not primarily established by the study) were collected into a database.

Results

In total, 3402 abstracts and 536 full-text papers were screened, and 232 papers were included. Our search established 53 synonyms for prolonged labor. Forty-three studies defined prolonged labor and 189 studies adopted a definition of prolonged labor. Definitions for prolonged first stage of labor were categorized into: time-based (n=14), progress-based (n=12), clinician-based (n=5), or outcome-based (n=4). For the 33 studies defining prolonged second stage, the majority of definitions (n=25) were time-based, either based on total duration or duration of no descent of the presenting part.

Conclusions

Despite efforts to arrive at uniform labor curves, there is still little uniformity in definitions of prolonged labor. Consensus on which definition to use is called for, in order to safely and respectfully allow physiological labor progress, ensure timely management, and assess and compare incidence of prolonged labor between settings.

Pelvic floor dysfunction after intervention, compared with expectant management, in prolonged second stage of labour: A population-based questionnaire and cohort study

OBJECTIVE

To investigate the effect of vacuum extraction (VE) or caesarean section (CS), compared with expectant management, on pelvic floor dysfunction (PFD) 1-2 years postpartum in primiparous women with a prolonged second stage of labour.

DESIGN

A population-based questionnaire and cohort study.

SETTING

Stockholm, Sweden.

POPULATION

A cohort of 1302 primiparous women with a second stage duration of ≥3 h, delivering from December 2017 to November 2018.

METHODS

The 1-year follow-up questionnaire from the Swedish National Perineal Laceration Register was distributed 12-24 months postpartum. Exposure was VE or CS at 3-4 h or 4-5 h, compared with expectant management.

MAIN OUTCOME MEASURES

Pelvic floor dysfunction was defined as at least weekly symptoms of urinary incontinence, pelvic organ prolapse or a Wexner score of ≥4. The risk of PFD was calculated using Poisson regression with robust variance estimation, presented as crude and adjusted relative risks (RRs and aRRs) with 95% confidence intervals (95% CIs). The implication of obstetric anal sphincter injury (OASI) on pelvic floor disorders was investigated through mediation analysis.

RESULTS

In total, 35.1% of women reported PFD. Compared with expectant management, the risk of PFD was increased after VE at 3-4 h (aRR 1.33, 95% CI 1.06-1.65) and 4-5 h (aRR 1.34, 95% CI 1.05-1.70), but remained unchanged after CS. The increased risk after VE was not mediated by OASI.

CONCLUSIONS

Pelvic floor dysfunction was common in primiparous women after a prolonged second stage, and the risk of PFD increased after VE but was unaffected by CS, compared with expectant management. If a spontaneous vaginal delivery eventually occurred, allowing an extended duration of labour did not increase the risk of PFD.

The effect of intravenous hyoscine butylbromide on slow progress in labor (BUSCLAB): A double-blind randomized placebo-controlled trial

BACKGROUND

Prolonged labor is a common condition associated with maternal and perinatal complications. The standard treatment with oxytocin for augmentation of labor increases the risk of adverse outcomes. Hyoscine butylbromide is a spasmolytic drug with few side effects shown to shorten labor when used in a general population of laboring women. However, research on its effect on preventing prolonged labor is lacking. We aimed to assess the effect of hyoscine butylbromide on the duration of labor in nulliparous women showing early signs of slow labor.

METHODS AND FINDINGS

In this double-blind randomized placebo-controlled trial, we included 249 nulliparous women at term with 1 fetus in cephalic presentation and spontaneous start of labor, showing early signs of prolonged labor by crossing the alert line of the World Health Organization (WHO) partograph. The trial was conducted at Oslo University Hospital in Norway from May 2019 to December 2021. One hundred and twenty-five participants were randomized to receive 1 ml hyoscine butylbromide (Buscopan) (20 mg/ml), while 124 received 1 ml sodium chloride intravenously. Randomization was computer-generated, with allocation concealment by opaque sequentially numbered sealed envelopes. The primary outcome was duration of labor from administration of the investigational medicinal product (IMP) to vaginal delivery, which was analyzed by Weibull regression to estimate the cause-specific hazard ratio (HR) of vaginal delivery between the 2 treatment groups, with associated 95% confidence interval (CI). A wide range of secondary maternal and perinatal outcomes were also evaluated. Time-to-event outcomes were analyzed by Weibull regression, whereas continuous and dichotomous outcomes were analyzed by median regression and logistic regression, respectively. All main analyses were based on the modified intention-to-treat (ITT) set of eligible women with signed informed consent receiving either of the 2 treatments. The follow-up period lasted during the postpartum hospital stay. All personnel, participants, and researchers were blinded to the treatment allocation. Median (mean) labor duration from IMP administration to vaginal delivery was 401 (440.8) min in the hyoscine butylbromide group versus 432.5 (453.6) min in the placebo group. We found no statistically significant association between IMP and duration of labor from IMP administration to vaginal delivery: cause-specific HR of 1.00 (95% CI [0.77, 1.29]; p = 0.993). Among 255 randomized women having received 1 dose of IMP, 169 women (66.3%) reported a mild adverse event: 75.2% in the hyoscine butylbromide group and 57.1% in the placebo group (Pearson's chi-square test: p = 0.002). More than half of eligible women were not included in the study because they did not wish to participate or were not included upon admission. The participants might have represented a selected group of women reducing the external validity of the study.

CONCLUSIONS

One intravenous dose of 20 mg hyoscine butylbromide was not found to be superior to placebo in preventing slow labor progress in a population of first-time mothers at risk of prolonged labor. Further research is warranted to answer whether increased and/or repeated doses of hyoscine butylbromide might have an effect on duration of labor.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03961165) EudraCT (2018-002338-19).

Moderate or intensive management of the active phase of second-stage labor and risk of urinary and anal incontinence: results of the PASST randomized controlled trial

BACKGROUND

Incontinence occurs frequently in the postpartum period. Several theoretical pathophysiological models may underlie the hypothesis that different types of management of the active phase of the second stage of labor have different effects on pelvic floor muscles and thus perhaps affect urinary and anal continence.

OBJECTIVE

This study aimed to evaluate the impact of "moderate pushing" on the occurrence of urinary or anal incontinence compared with "intensive pushing," and to determine the factors associated with incontinence at 6 months postpartum.

STUDY DESIGN

This was a planned analysis of secondary objectives of the PASST (Phase Active du Second STade) trial, a multicenter randomized controlled trial. PASST included nulliparous women with singleton term pregnancies and epidural analgesia, who were randomly assigned at 8 cm of dilatation to either the intervention group that used "moderate" pushing (pushing only twice during each contraction, resting regularly for 1 contraction in 5 without pushing, and no time limit on pushing) or the control group following the usual management of "intensive" pushing (pushing 3 times during each contraction, with no contractions without pushing, with an obstetrician called to discuss operative delivery after 30 minutes of pushing). Data about continence were collected with validated self-assessment questionnaires at 6 months postpartum. Urinary incontinence was defined by an ICIQ-UI SF (International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form) score ≥1 and anal incontinence by a Wexner score ≥2. A separate analysis was also performed among the more severely affected women (ICIQ-UI SF ≥6 and Wexner ≥5). Factors associated with incontinence were assessed with univariate and multivariable analyses.

RESULTS

Among 1618 women initially randomized, 890 (55%) returned the complete questionnaire at 6 months. The rate of urinary incontinence was 36.6% in the "moderate" pushing group vs 38.5% in the "intensive" pushing group (relative risk, 0.95; 95% confidence interval, 0.80-1.13), whereas the rate of anal incontinence was 32.2% vs 34.6% (relative risk, 0.93; 95% confidence interval, 0.77-1.12). None of the obstetrical factors studied related to the second stage of labor influenced the occurrence of urinary or anal incontinence, except operative vaginal delivery, which increased the risk of anal incontinence (adjusted odds ratio, 1.50; 95% confidence interval, 1.04-2.15).

CONCLUSION

The results of the PASST trial indicate that neither moderate nor intensive pushing efforts affect the risk of urinary or anal incontinence at 6 months postpartum among women who gave birth under epidural analgesia.