{
  "abstract": "Objective To compare neurodevelopmental outcomes in extremely preterm (EPT) children born across two epochs in Sweden.Design and setting Nationwide population-based cohorts of infants born at 22–26 weeks’ gestation in 2004–2007 (Cohort 1) and 2014–2016 (Cohort 2), comprising 1606 live births. Survivors were assessed at 2–2.5 years’ corrected age using the same protocol design.Main outcome The primary outcome was neurodevelopmental impairment (NDI), defined as a composite of moderate–severe cerebral palsy (CP), visual or hearing deficits, or moderate–severe cognitive, language or motor impairment assessed with the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley III). For children not assessed with Bayley-III, NDI was defined as moderate–severe speech delay, general developmental delay or categories of CP, vision and hearing impairment. Outcomes were compared using logistic regression to evaluate differences between cohorts and perinatal and socioeconomic risk factors.Results Of 1188 eligible survivors, 1062 (89.3%) were assessed (mean gestational age (GA) 24.8 weeks; 54.9% male). The prevalence of moderate–severe NDI at 22, 23, 24, 25 and 26 weeks’ gestation was 60% vs 52%, 51% vs 51%, 34% vs 42%, 27% vs 32% and 17% vs 24% in Cohorts 1 and 2, respectively. Overall prevalence did not differ significantly (27% vs 35%; adjusted OR (AOR) 1.2, 95% CI 0.94 to 1.6). Among 724 (68%) children assessed with Bayley III, Cohort 2 had higher rates of cognitive delay (21.6% vs 11.3%; AOR 1.8, 95% CI 1.1 to 3.4) and language delay (40.9% vs 16.1%; AOR 3.3, 95% CI 1.4 to 4.1). Low GA and maternal country of birth outside the Nordic region were the strongest predictors of NDI and cognitive delay, the latter association confined to Cohort 2.Conclusion Although survival of EPT infants in Sweden has improved, long-term neurodevelopmental outcomes have not. The root causes of failed improvements in long-term outcomes for EPT infants are complex and need further clarification.",
  "authors": [
    {
      "affiliations": [
        "Woman and Child Health, Karolinska Institute, Stockholm, Sweden"
      ],
      "name": "Ulrika Ådén"
    },
    {
      "affiliations": [
        "Dept of Clinical sciences, Pediatrics, Umeå University, Umea, Västerbotten, Sweden"
      ],
      "name": "Aijaz Farooqi"
    },
    {
      "affiliations": [
        "Department of Womens and Childrens Health, Uppsala University, Uppsala, Sweden"
      ],
      "name": "Lena Hellstrom-Westas"
    },
    {
      "affiliations": [
        "Department of Pediatrics, University of Gothenburg Sahlgrenska Academy, Gotheburg, Sweden",
        "Department of Pediatrics, Sahlgrenska University Hospital, Gothenburg, SE, Sweden"
      ],
      "name": "Karin Sävman"
    },
    {
      "affiliations": [
        "Department of Biomedical and clinical sciences and departmet of Pediatrics, Linköping University, Linkoping, Sweden"
      ],
      "name": "Thomas Abrahamsson"
    },
    {
      "affiliations": [
        "Departments of Clinical Sciences and Pediatrics, Skåne University Hospital Lund, Lund, Sweden"
      ],
      "name": "Lars J Björklund"
    },
    {
      "affiliations": [
        "Department of Clinical Sciences, Pediatrics, Umeå University, Umea, Sweden"
      ],
      "name": "Magnus Domellöf"
    },
    {
      "affiliations": [
        "Department of Pediatrics, Institute of Clinical Sciences, University of Gothenburg Sahlgrenska Academy, Goteborg, Sweden",
        "Department of Pediatrics, Sahlgrenska University Hospital, Gothenburg, Sweden"
      ],
      "name": "Anders Elfvin"
    },
    {
      "affiliations": [
        "Department of Pediatrics, Linköping University, Linkoping, Östergötland, Sweden"
      ],
      "name": "Fredrik Ingemansson"
    },
    {
      "affiliations": [
        "Department of Women's and Children's Health, Pediatrics, Uppsala University, Uppsala, Uppsala, Sweden"
      ],
      "name": "Fredrik Serenius"
    },
    {
      "affiliations": [
        "Department of Clinical Sciences, Pediatrics, Umeå University, Umea, Sweden"
      ],
      "name": "Stellan Hakansson"
    },
    {
      "affiliations": [
        "Institution of Clinical Sciences,Pediatrics, Lund University, Lund, Sweden"
      ],
      "name": "David Ley"
    },
    {
      "affiliations": [
        "Department of Womens and Childrens Health, Uppsala University, Uppsala, Sweden"
      ],
      "name": "Erik Normann"
    },
    {
      "affiliations": [
        "Clinical Science and Education at Södersjukhuset, Karolinska Institute, Stockholm, Sweden"
      ],
      "name": "Petra Um Bergström"
    },
    {
      "affiliations": [
        "Department of Reproductive Epidemiology, Lund University, Lund, Sweden"
      ],
      "name": "Karin Kallen"
    },
    {
      "affiliations": [
        "Department of Clinical Sciences, Division of Pediatrics, Intervention and Technology, Karolinska Institute, Stockholm, Sweden",
        "Department of Neonatal Medicine, Karolinska University Hospital, Stockholm, Sweden"
      ],
      "name": "Mikael Norman"
    }
  ],
  "title": "Long-term neurodevelopmental outcomes in extremely preterm infants born at 22–26 weeks gestation: a follow-up of 2–2.5 years across two Swedish national cohorts from 2004–2007 to 2014–2016",
  "uid": "aa4efbf6-ccff-5ab7-8f8d-7a4fc6047482"
}