Association between perinatal interventional activity and 2-year outcome of Swiss extremely preterm born infants: a population-based cohort study

Abstract

ObjectivesTo investigate if centre-specific levels of perinatal interventional activity were associated with neonatal and neurodevelopmental outcome at 2 years of age in two separately analysed cohorts of infants: cohort A born at 22–25 and cohort B born at 26–27 gestational weeks, respectively.DesignGeographically defined, retrospective cohort study.SettingAll nine level III perinatal centres (neonatal intensive care units and affiliated obstetrical services) in Switzerland.PatientsAll live-born infants in Switzerland in 2006–2013 below 28 gestational weeks, excluding infants with major congenital malformation.Outcome measuresOutcomes at 2 years corrected for prematurity were mortality, survival with any major neonatal morbidity and with severe-to-moderate neurodevelopmental impairment (NDI).ResultsCohort A associated birth in a centre with high perinatal activity with low mortality adjusted OR (aOR 0.22; 95% CI 0.16 to 0.32), while no association was observed with survival with major morbidity (aOR 0.74; 95% CI 0.46 to 1.19) and with NDI (aOR 0.97; 95% CI 0.46 to 2.02). Median age at death (8 vs 4 days) and length of stay (100 vs 73 days) were higher in high than in low activity centres. The results for cohort B mirrored those for cohort A.ConclusionsCentres with high perinatal activity in Switzerland have a significantly lower risk for mortality while having comparable outcomes among survivors. This confirms the results of other studies but in a geographically defined area applying a more restrictive approach to initiation of perinatal intensive care than previous studies. The study adds that infants up to 28 weeks benefited from a higher perinatal activity and why further research is required to better estimate the added burden on children who ultimately do not survive.

Intensity of perinatal care for extremely preterm babies and outcomes at a higher gestational age: evidence from the EPIPAGE-2 cohort study

“…Two previous studies that examined the same hypothesis as this paper demonstrated better outcomes for babies born at a higher gestational age [12,13]. However, both studies suffered from selection bias.…”

“…Data were collected over eight years, meaning there may have been changes in attitude within centres during the study period. They found important differences in survival and the odds of major neonatal morbidities, weaker evidence for an effect on mortality and neurodevelopmental impairment combined, and no evidence of a difference in neurodevelopmental impairment amongst survivors at two years of age [12]. There is a clear coherence in these results with our study: both support the idea that there is no relationship between the intensity of perinatal activity provided to extremely preterm babies and outcomes at two years of age for those born at a higher gestational age.…”

“…A second study, conducted in Switzerland, included only live born babies yet their indicator included measures of obstetric activity [12]. Data were collected over eight years, meaning there may have been changes in attitude within centres during the study period.…”

“…Specifically, units that are more active in their care for extremely preterm babies may develop expertise that also leads to improved outcomes for babies born at a higher gestational age. A study examining this question among live born babies demonstrated improved outcomes at hospital discharge [12]. The "perinatal interventional activity score", however, was partly based upon obstetric measures and thus did not take into consideration treatments for fetuses who died during labour.…”

Higher incidence of retinopathy of prematurity in extremely preterm infants associated with improved survival rates

“…20 Other studies documented a remarkable outcome variability between Swiss perinatal centres, which to a certain extent can be seen as the result of different local ethical approaches to providing intensive care to extremely preterm infants. 21 Finally, a comparison between Swiss perinatal centres with higher versus lower perinatal interventional activity at the limit of viability revealed that higher activity significantly decreased the risk of mortality and led to comparable outcomes regarding neurodevelopmental impairment at 2 years of life 22 and thereby matched observations from Sweden. 23 In this context, it is noteworthy that survival increased particularly at a GA < 25 weeks during our study period.…”