Varying gestational age patterns in cesarean delivery: an international comparison

Abstract

BackgroundWhile international variations in overall cesarean delivery rates are well documented, less information is available for clinical sub-groups. Cesarean data presented by subgroups can be used to evaluate uptake of cesarean reduction policies or to monitor delivery practices for high and low risk pregnancies based on new scientific evidence. We studied differences and patterns in cesarean delivery rates by multiplicity and gestational age in Europe and the United States.MethodsThis study used routine aggregate data from 17 European countries and the United States on the number of singleton and multiple live births with cesarean versus vaginal delivery by week of gestation in 2008. Overall and gestation-specific cesarean delivery rates were analyzed. We computed rate differences to compare mode of delivery (cesarean vs vaginal birth) between selected gestational age groups and studied associations between rates in these subgroups namely: very preterm (26–31 weeks GA), moderate preterm (32–36 weeks GA), near term (37–38 weeks GA), term (39–41 weeks GA) and post-term (42+ weeks GA) births, using Spearman’s rank tests.ResultsHigh variations in cesarean rates for singletons and multiples were observed everywhere. Rates for singletons varied from 15% in The Netherlands and Slovenia, to over 30% in the US and Germany. In singletons, rates were highest for very preterm births and declined to a nadir at 40 weeks of gestation, ranging from 8.0% in Sweden and Norway, to 22.5% in the US. These patterns differed across countries; the average rate difference between very preterm and term births was 43 percentage points, but ranged from 14% to 61%. High variations in rate differences were also observed for near term versus term births. For multiples, rates declined by gestational age in some countries, whereas in others rates were similar across all weeks of gestation. Countries’ overall cesarean rates were highly correlated with gestation-specific subgroup rates, except for very preterm births.ConclusionsGestational age patterns in cesarean delivery were heterogeneous across countries; these differences highlight areas where consensus on best practices is lacking and could be used in developing strategies to reduce cesareans.

Epidemiology of late preterm and early term births – An international perspective

“…However, evidence on these risks is not straightforward and this results in variations in obstetric intervention across countries [63]. For instance, cesarean rates for singletons 32-36 weeks were between 27% and 52% and for early term between 19% and 47% in 18 high-income countries in 2008 [64]. In one study investigating clinician-initiated deliveries, the USA displayed the highest rates of intervention among late preterm and early births (44% and 42%, respectively); compared to Sweden (24.5% and 36.9%) [23].…”

Risk of intellectual disability in children born appropriate-for-gestational-age at term or post-term: impact of birth weight for gestational age and gestational age

“…We identified maternal and neonatal variables that have been associated with both birth weight for gestational age/gestational age and risk of intellectual disability and might therefore confound the associations under study. As a result, we extracted information on maternal age at delivery [22,23], parity [22,24], smoking during pregnancy [7,25], maternal height and weight collected at the first antenatal care visit, onset of labor [25,26], mode of delivery [25,27,28], and child's sex [22,29] from the Medical Birth Register. Body mass index (BMI) in early pregnancy [22,30] was calculated by dividing measured weight (kg) by self-reported height squared (m 2 ).…”

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“…29 Delnord et al investigated CD trends on an international level and found exceedingly high rates amongst very preterm births. 31 There are many potential underlying indications for CD in this cohort, such as malpresentation, demonstrated fetal intolerance to labor, maternal indication for immediate delivery, and higher order multiples. However, since it has been suggested by others that there may exist inherent advantage to avoidance of labor in infants of lower birth weight, the increased CD rate may also be a result of perceived benefit relative to risk.…”