Just Pop It: Early AROM After Cervical Ripening Reduces the Time to Delivery

In pregnant patients at term undergoing induction of labor, early time-based artificial rupture of membranes (AROM) within 1 hour of Foley bulb expulsion results in a shorter duration of labor by nearly 9 hours with no significant difference in cesarean delivery rates or maternal or neonatal adverse outcomes.1.

Artificial rupture of membranes as a mode for induction of labor in women with a previous cesarean section- a retrospective cohort study

BACKGROUND

Induction of labor in women with a previous cesarean section (CS) is associated with increased rates of uterine rupture and failed attempt for vaginal delivery. Prostaglandins use is contraindicated in this population, limiting available options for cervical ripening.

OBJECTIVE

To evaluate the efficacy and safety of artificial rupture of membranes (AROM) as a mode of Induction of labor (IOL) in women with a previous cesarean section.

METHODS

A retrospective cohort study conducted in a single tertiary care center between January 2015 and October 2020. Women with one previous cesarean section and a current singleton term pregnancy requiring IOL, with an unfavorable cervix, were included. The primary outcome was a successful vaginal delivery (VBAC); secondary outcomes were rates of chorioamnionitis, uterine rupture and low Apgar score (< 7).

RESULTS

Of the 665 women who met the inclusion criteria, 492 (74%) did not receive subsequent oxytocin and 173 (26%) did. There were significant differences in the baseline characteristics between these two groups, including maternal age, cervical dilation at presentation, parity, and a history of a previous VBAC. Among women who were induced solely by AROM the rate of a successful TOLAC was higher (81.3% vs 73.9%), total time of IOL was shorter (mean 8.7 h vs.16.1 h) and the risk of chorioamnionitis was lower (7.3% vs 18.4%). When subdividing the women who received oxytocin into early (< 12 h after AROM) vs late (> 12 h after AROM) administration, there were no significant changes in the rates of successful VBAC or of chorioamnionitis.

CONCLUSION

AROM as a single mode of IOL in women with a previous CS is a safe and efficient practice with high rates of successful VBAC. When spontaneous labor does not develop, there is no advantage to delay the administration of oxytocin.

Prevalence of amniotomy in Sweden: a nationwide register study

BACKGROUND

Amniotomy is a commonly used labor intervention with uncertain evidence, and there are complications connected to the intervention. Yet, the Swedish prevalence of amniotomy is unknown. The aim of the study was therefore to describe the prevalence of amniotomy in Sweden.

METHODS

This nationwide register-based study included 330,913 women giving birth in 2017-2020. Data were collected from the Swedish Pregnancy Register in which the majority of data is collected via direct transfer from medical records. Prevalence of amniotomy was described for all births, for nulliparous and multiparous women with spontaneous onset of labour, and at the hospital level. Descriptive statistics and chi-square test were used to analyse the data.

RESULTS

For all births, the prevalence of amniotomy was 40.6%. More amniotomies were performed in Robson group 1 compared to Robson group 3; 41.1% vs 32.3% (p < 0.001). The prevalence for all births remained the same during the study period; however, a decrease from 37.5 to 34.1%, was seen in Robson group 1 and Robson group 3 (p < 0.001). Variations in the prevalence between hospitals were reported. The hospitals with the fewest number of births annually had the highest prevalence of amniotomy (45.0%), and the lowest prevalence was reported at the University hospitals (40.4%) (p < 0.001).

CONCLUSIONS

Amniotomy is a common labor intervention in Sweden, given that almost half of the laboring women underwent the intervention. Our results, regarding variations in the prevalence between hospitals, could imply a potential for fewer amniotomies in Swedish childbirth care.

Modifiable and non-modifiable risk factors for obstetric anal sphincter injury in a Norwegian Region: a case-control study

Background

Obstetric anal sphincter injury (OASI) is a common and severe complication of vaginal delivery and may have short- and long-term consequences, including anal incontinence, sexual dysfunction and reduced quality of life. The rate of OASI varies substantially between studies and national birth statistics, and a recent meta-analysis concluded that there is a need to identify unrecognized risk factors. Our aim was therefore to explore both potential modifiable and non-modifiable risk factors for OASI.

Methods

We performed a case–control study in a single center maternity clinic in South-Eastern Norway. Data were extracted retrospectively from an institutional birth registry. The main outcome measure was the occurrence of the woman’s first-time 3^rd or 4^th degree perineal lesion (OASI) following singleton vaginal birth after 30 weeks’ gestation. For each woman with OASI the first subsequent vaginal singleton delivery matched for parity was elected as control. The study population included 421 women with OASI and 421 matched controls who gave birth during 1990–2002. Potential risk factors for OASI were assessed by conditional logistic regression analyses.

Results

The mean incidence of OASI was 3.4% of vaginal deliveries, but it increased from 1.9% to 5.8% during the study period. In the final multivariate regression model, higher maternal age and birthweight for primiparous women, and higher birthweight for the multiparous women, were the only non-modifiable variables associated with OASI. Amniotomy was the strongest modifiable risk factor for OASI in both primi- (odds ratio [OR] 4.84; 95% confidence interval [CI] 2.60–9.02) and multiparous (OR 3.76; 95% CI 1.45–9.76) women, followed by augmentation with oxytocin (primiparous: OR 1.63; 95% CI 1.08–2.46, multiparous: OR 3.70; 95% CI 1.79–7.67). Vacuum extraction and forceps delivery were only significant risk factors in primiparous women (vacuum: OR 1.91; 95% CI 1.03–3.57, forceps: OR 2.37; 95% CI 1.14–4.92), and episiotomy in multiparous women (OR 2.64; 95% CI 1.36–5.14).

Conclusions

Amniotomy may be an unrecognized independent modifiable risk factor for OASI and should be further investigated for its potential role in preventive strategies.

Amniotomy and early oxytocin infusion vs amniotomy and delayed oxytocin infusion for labour augmentation amongst nulliparous women at term: A randomised controlled trial

OBJECTIVE

to compare the effect of amniotomy with early vs delayed oxytocin infusion on successful vaginal delivery.

DESIGN

randomised controlled trial of nulliparous women with spontaneous labour at term.

SETTING

labour suite of a university teaching hospital in Kuala Lumpur, Malaysia.

PARTICIPANTS

240 women were included (120 randomised into two arms).

INTERVENTIONS

the randomisation sequence was generated using a computer randomisation program in two blocks: oxytocin infused early following amniotomy; and oxytocin infused 2 h after amniotomy.

MEASUREMENTS AND FINDINGS

labour duration, mode of delivery, oxytocin dosage used, uterine hyperstimulation, postpartum haemorrhage, Apgar score and admission to the neonatal intensive care unit were recorded. No differences in vaginal delivery rate (62.9% vs 70.9%; p = 0.248) and second-stage labour were found between the early and delayed oxytocin infusion groups (21.2 ± 18.3 min vs 25.5 ± 19.9 min; p = 0.220). The mean interval from amniotomy to vaginal delivery was significantly shorter for the early group (5.8 ± 1.7 h vs 7.0 ± 1.9 h; p = 0.001), and more women in the early group delivered during/before the planned review at 4 h after amniotomy (53.6% vs 10.6%; p<0.001). Maximum oxytocin usage was lower in the early group (5.6 ± 4.4 mL/hour vs 6.8 ± 5.3 mL/hour; p = 0.104).

KEY CONCLUSIONS

early oxytocin augmentation following amniotomy could be employed in low-risk primigravida, given that it is associated with a shorter labour duration without jeopardising maternal or neonatal outcomes.

IMPLICATIONS FOR PRACTICE

low-risk primigravida benefit from early oxytocin infusion following amniotomy, and this can be offered as an additional practice in labour room care.

Management of prolonged first stage of labour in a low-resource setting: lessons learnt from rural Malawi

Background

Caesarean sections without medical indication cause substantial maternal and perinatal ill-health, particularly in low-income countries where surgery is often less safe. In presence of adequate labour monitoring and by appropriate use of evidence-based interventions for prolonged first stage of labour, unnecessary caesarean sections can be avoided. We aim to describe the incidence of prolonged first stage of labour and the use of amniotomy and augmentation with oxytocin in a low-resource setting in Malawi.

Methods

Retrospective analysis of medical records and partographs of all women who gave birth in 2015 and 2016 in a rural mission hospital in Malawi. Primary outcomes were incidence of prolonged first stage of labour based on partograph tracings, caesarean section indications and utilization of amniotomy and oxytocin augmentation.

Results

Out of 3246 women who gave birth in the study period, 178 (5.2%) crossed the action line in the first stage of labour, of whom 21 (11.8%) received oxytocin to augment labour. In total, 645 women gave birth by caesarean section, of whom 241 (37.4%) with an indication ‘prolonged first stage of labour’. Only 113 (46.9%) of them crossed the action line and in 71/241 (29.5%) membranes were still intact at the start of caesarean section. Excluding the 60 women with prior caesarean sections, 14/181 (7.7%) received oxytocin prior to caesarean section for augmentation of labour.

Conclusion

The diagnosis prolonged first stage of labour was often made without being evident from labour tracings and two basic obstetric interventions to prevent caesarean section, amniotomy and labour augmentation with oxytocin, were underused.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03856-9.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

Cervical Ripening and Labor Induction and Augmentation, 5th Edition

Cervical ripening and induction and augmentation of labor are common procedures in labor and birth units. The potential risks and benefits for the procedure should be explained to women so that they can make informed decisions. Clinicians should be knowledgeable about the methods and medications used and be skilled in maternal-fetal assessment. Adequate nurse staffing is required to monitor the mother and fetus to promote the best possible outcomes. This practice monograph includes information on mechanical and pharmacologic methods for cervical ripening; labor induction and augmentation with oxytocin, a high alert drug; and nurse staffing levels and skills needed to provide safe and effective care during cervical ripening and labor induction and augmentation.

General methods for measuring and comparing medical interventions in childbirth: a framework

Background

The continue increase of interventions during labour in low risk population is a controversial issue of the current obstetric literature, given the lack of evidence demonstrating the benefits of unnecessary interventions for women or infants’ health. This makes it important to have approaches to assess the burden of all medical interventions performed.

Methods

Exploiting the nature of childbirth intervention as a staged process, we proposed graphic representations allowing to generate alternative formulas for the simplest measures of the intervention intensity namely, the overall and type-specific treatment ratios. We applied the approach to quantify the change in interventions following a protocol termed Comprehensive Management (CM), using data from Robson classification, collected in a prospective longitudinal cohort study carried out at the Obstetric Unit of the Cà Granda Niguarda Hospital in Milan, Italy.

Results

Following CM a substantial reduction was observed in the Overall Treatment Ratio, as well as in the ratios for augmentation (amniotomy and synthetic oxytocin use) and for caesarean section ratio, without any increase in neonatal and maternal adverse outcomes. The key component of this reduction was the dramatic decline in the proportion of women progressing to augmentation, which resulted not only the most practiced intervention, but also the main door towards further treatments.

Conclusions

The proposed framework, once combined with Robson Classification, provides useful tools to make medical interventions performed during childbirth quantitatively measurable and comparable. The framework allowed to identifying the key components of interventions reduction following CM. In its turn, CM proved useful to reduce the number of medical interventions carried out during childbirth, without worsening neonatal and maternal outcomes.

Augmentation of labour

Augmentation of labour aims at improving the efficiency of uterine contractions in order to reduce maternal and foetal adverse outcomes associated with prolonged labour. This review covers the current best practice for different methods of augmentation of labour, namely, artificial rupture of membranes and oxytocin infusion as a prevention of, or therapy for, prolonged labour. The review highlights essential practice points and identifies knowledge gaps for future research in this important area of clinical obstetric practice.

Labor augmentation strategies: What's the evidence?

Labor augmentation is a commonly used strategy in obstetrics to make labor more efficient or to increase the chance of achieving a vaginal delivery. Intravenous infusion of synthetic oxytocin and early amniotomy are the most widely used methods, but there is considerable variation in how they are used in clinical practice. There remain significant differences in the timing, dosing, and administration of synthetic oxytocin across institutions. The use and timing of amniotomy is similarly controversial. Much of the clinical variation in augmentation practices stem from the significant heterogeneity that exists in the literature, as well as the lack of an optimal strategy that has been subjected to the scientific scrutiny needed to prove its superiority in both efficacy and safety. Further research is needed to allow for better standardized care of women presenting in spontaneous labor.

[Does rupture of membranes have an impact on the fetal heart rate during spontaneous labor?]

OBJECTIVES

Evaluate the influence of rupture of membranes (spontaneous or artificial) on fetal heart rate. Secondary objectives were to compare spontaneous and artificial ruptures and to investigate the risk factors associated with the occurrence of abnormalities of fetal heart rate (FHR).

METHODS

This is a monocentric retrospective study (Lille, France) from January to March 2018. All low-risk pregnancies with cephalic presentation, spontaneous labor, gestational age more than 37 weeks of amenorrhea, singleton pregnancy, absence of maternal or fetal pathology were included. The elements sought were the occurrence of bradycardia, tachycardia, decelerations (early, late, typical variable, atypical variable, prolonged) and abnormal variability. FHR was analyzed one hour before and one hour after rupture. The groups with and without abnormalities of FHR were compared according to the type of rupture.

RESULTS

Two hundred and thirty-three patients were included. A total of 44.54% (n=129, P<0.001) showed abnormalities of FHR after rupture of membranes. In the fetal heart rate time study after the rupture event, prolonged decelerations were more frequent in the first quarter hour compared to the second quarter hour. There was significantly more risk of abnormalities of fetal heart rate if the fetal heart rate before the rupture of membranes was already pathological, as well as if the time between rupture and delivery was short. The type of rupture, artificial or spontaneous, was not a risk factor.

CONCLUSION

The rupture of membranes increased the occurrence of abnormalities of FHR. However, there is no more deleterious impact of one type of rupture than the other.

The association between delayed amniotomy and adverse outcomes in labor induction

OBJECTIVE

To assess if delayed amniotomy during labor induction is associated with adverse delivery outcomes.

STUDY DESIGN

Retrospective cohort study of women with a viable, singleton gestation who underwent labor induction at a tertiary-care hospital (4/2014-3/2017). Women were excluded if oxytocin was not used or if spontaneous rupture of membranes (ROM) occurred ≤8 h after oxytocin initiation. The primary outcome was cesarean delivery, and secondary outcomes included postpartum hemorrhage, maternal infectious morbidity, neonatal 5-min Apgar score <7, and neonatal intensive care unit admission. Women were compared by timing of amniotomy: delayed (ROM > 8 h after oxytocin initiation) versus not delayed. Multivariable logistic regression was used to estimate the association between delayed amniotomy and study outcomes.

RESULTS

Of 2081 women who met inclusion criteria, 1125 (before 54%) had delayed amniotomy. Women with delayed amniotomy had ROM 12.7 h (IQR 10.0, 17.9) after oxytocin versus 5.0 h (IQR 3.7, 6.5) without delayed amniotomy. In multivariable regression, delayed amniotomy was associated with increasingly higher odds of cesarean as maternal obesity severity increased (aOR 1.58, 95 %CI 1.24-2.03 at BMI 30 kg/m²; aOR 2.15, 95 %CI 1.45-3.21 at BMI 40 kg/m²; aOR 2.93, 95 %CI 1.54-5.57 at BMI 50 kg/m²).

CONCLUSION

Delayed amniotomy >8 h after starting oxytocin for labor induction was associated with higher odds of cesarean delivery. Significant delay in ROM should be avoided during labor induction.

Labor Induction Techniques: Which Is the Best?

Induction of labor is a common procedure undertaken whenever the benefits of prompt delivery outweigh the risks of expectant management. Cervical assessment is essential to determine the optimal approach. Indication for induction, clinical presentation and history, safety, cost, and patient preference may factor into the selection of methods. For the unfavorable cervix, several pharmacologic and mechanical methods are available, each with associated advantages and disadvantages. In women with a favorable cervix, combined use of amniotomy and intravenous oxytocin is generally the most effective approach. The goal of labor induction is to ensure the best possible outcome for mother and newborn.