How much synthetic oxytocin is infused during labour? A review and analysis of regimens used in 12 countries.

OBJECTIVE: To compare synthetic oxytocin infusion regimens used during labour, calculate the International Units (IU) escalation rate and total amount of IU infused over eight hours. DESIGN: Observational study. SETTING: Twelve countries, eleven European and South Africa. SAMPLE: National, regional or institutional-level regimens on oxytocin for induction and augmentation labour. METHODS: Data on oxytocin IU dose, infusion fluid amount, start dose, escalation rate and maximum dose were collected. Values for each regimen were converted to IU in 1000ml diluent. One IU corresponded to 1.67µg for doses provided in grams/micrograms. IU hourly dose increase rates were based on escalation frequency. Cumulative doses and total IU amount infused were calculated by adding the dose administered for each previous hour. Main Outcome Measures Oxytocin IU dose infused. RESULTS: Data were obtained on 21 regimens used in 12 countries. Details on the start dose, escalation interval, escalation rate and maximum dose infused were available from 16 regimens. Starting rates varied from 0.06 IU/hour to 0.90 IU/hour, and the maximum dose rate varied from 0.90 IU/hour to 3.60 IU/hour. The total amount of IU oxytocin infused, estimated over eight hours, ranged from 2.38 IU to 27.00 IU, a variation of 24.62 IU and an 11-fold difference. CONCLUSION: Current variations in oxytocin regimens for induction and augmentation of labour are inexplicable. It is crucial that the appropriate minimum infusion regimen is administered because synthetic oxytocin is a potentially harmful medication with serious consequences for women and babies when inappropriately used. Estimating the total amount of oxytocin IU received by labouring women, alongside the institution's mode of birth and neonatal outcomes, may deepen our understanding and be the way forward to identifying the optimal infusion regimen.

Variations in use of childbirth interventions in 13 high-income countries: A multinational cross-sectional study.

BACKGROUND: Variations in intervention rates, without subsequent reductions in adverse outcomes, can indicate overuse. We studied variations in and associations between commonly used childbirth interventions and adverse outcomes, adjusted for population characteristics. METHODS AND FINDINGS: In this multinational cross-sectional study, existing data on 4,729,307 singleton births at ≥37 weeks in 2013 from Finland, Sweden, Norway, Denmark, Iceland, Ireland, England, the Netherlands, Belgium, Germany (Hesse), Malta, the United States, and Chile were used to describe variations in childbirth interventions and outcomes. Numbers of births ranged from 3,987 for Iceland to 3,500,397 for the USA. Crude data were analysed in the Netherlands, or analysed data were shared with the principal investigator. Strict variable definitions were used and information on data quality was collected. Intervention rates were described for each country and stratified by parity. Uni- and multivariable analyses were performed, adjusted for population characteristics, and associations between rates of interventions, population characteristics, and outcomes were assessed using Spearman's rank correlation coefficients. Considerable intercountry variations were found for all interventions, despite adjustments for population characteristics. Adjustments for ethnicity and body mass index changed odds ratios for augmentation of labour and episiotomy. Largest variations were found for augmentation of labour, pain relief, episiotomy, instrumental birth, and cesarean section (CS). Percentages of births at ≥42 weeks varied from 0.1% to 6.7%. Rates among nulliparous versus multiparous women varied from 56% to 80% versus 51% to 82% for spontaneous onset of labour; 14% to 36% versus 8% to 28% for induction of labour; 3% to 13% versus 7% to 26% for prelabour CS; 16% to 48% versus 12% to 50% for overall CS; 22% to 71% versus 7% to 38% for augmentation of labour; 50% to 93% versus 25% to 86% for any intrapartum pain relief, 19% to 83% versus 10% to 64% for epidural anaesthesia; 6% to 68% versus 2% to 30% for episiotomy in vaginal births; 3% to 30% versus 1% to 7% for instrumental vaginal births; and 42% to 70% versus 50% to 84% for spontaneous vaginal births. Countries with higher rates of births at ≥42 weeks had higher rates of births with a spontaneous onset (rho = 0.82 for nulliparous/rho = 0.83 for multiparous women) and instrumental (rho = 0.67) and spontaneous (rho = 0.66) vaginal births among multiparous women and lower rates of induction of labour (rho = -0.71/-0.66), prelabour CS (rho = -0.61/-0.65), overall CS (rho = -0.61/-0.67), and episiotomy (multiparous: rho = -0.67). Variation in CS rates was mainly due to prelabour CS (rho = 0.96). Countries with higher rates of births with a spontaneous onset had lower rates of emergency CS (nulliparous: rho = -0.62) and higher rates of spontaneous vaginal births (multiparous: rho = 0.70). Prelabour and emergency CS were positively correlated (nulliparous: rho = 0.74). Higher rates of obstetric anal sphincter injury following vaginal birth were found in countries with higher rates of spontaneous birth (nulliparous: rho = 0.65). In countries with higher rates of epidural anaesthesia (nulliparous) and spontaneous births (multiparous), higher rates of Apgar score < 7 were found (rhos = 0.64). No statistically significant variation was found for perinatal mortality. Main limitations were varying quality of data and missing information. CONCLUSIONS: Considerable intercountry variations were found for all interventions, even after adjusting for population characteristics, indicating overuse of interventions in some countries. Multivariable analyses are essential when comparing intercountry rates. Implementation of evidence-based guidelines is crucial in optimising intervention use and improving quality of maternity care worldwide.

Variations in childbirth interventions in high-income countries: protocol for a multinational cross-sectional study.

INTRODUCTION: There are growing concerns about the increase in rates of commonly used childbirth interventions. When indicated, childbirth interventions are crucial for preventing maternal and perinatal morbidity and mortality, but their routine use in healthy women and children leads to avoidable maternal and neonatal harm. Establishing ideal rates of interventions can be challenging. This study aims to describe the range of variations in the use of commonly used childbirth interventions in high-income countries around the world, and in outcomes in nulliparous and multiparous women. METHODS AND ANALYSIS: This multinational cross-sectional study will use data from births in 2013 with national population data or representative samples of the population of pregnant women in high-income countries. Data from women who gave birth to a single child from 37 weeks gestation onwards will be included and the results will be presented for nulliparous and multiparous women separately. Anonymised individual level data will be analysed. Primary outcomes are rates of commonly used childbirth interventions, including induction and/or augmentation of labour, intrapartum antibiotics, epidural and pharmacological pain relief, episiotomy in vaginal births, instrument-assisted birth (vacuum or forceps), caesarean section and use of oxytocin postpartum. Secondary outcomes are maternal and perinatal mortality, Apgar score below 7 at 5 min, postpartum haemorrhage and obstetric anal sphincter injury. Univariable and multivariable logistic regression analyses will be conducted to investigate variations among countries, adjusted for maternal age, body mass index, gestational weight gain, ethnic background, socioeconomic status and infant birth weight. The overall mean rates will be considered as a reference category, weighted for the size of the study population per country. ETHICS AND DISSEMINATION: The Medical Ethics Review Committee of VU University Medical Center Amsterdam confirmed that an official approval of this study was not required. Results will be disseminated at national and international conferences and published in peer-reviewed journals.