Epidemiology of subdural haemorrhage during infancy: A population-based register study

Abstract

ObjectivesTo analyse subdural haemorrhage (SDH) during infancy in Sweden by incidence, SDH category, diagnostic distribution, age, co-morbidity, mortality, and maternal and perinatal risk factors; and its association with accidents and diagnosis of abuse.MethodsA Swedish population-based register study comprising infants born between 1997 and 2014, 0–1 years of age, diagnosed with SDH-diagnoses according to the (International Classification of Diseases, 10th version (ICD10), retrieved from the National Patient Register and linked to the Medical Birth Register and the Death Cause Register. Outcome measures were: 1) Incidence and distribution, 2) co-morbidity, 3) fall accidents by SDH category, 4) risk factors for all SDHs in the two age groups, 0–6 and 7–365 days, and for ICD10 SDH subgroups: S06.5 (traumatic SDH), I62.0 (acute nontraumatic), SDH and abuse diagnosis.ResultsIncidence of SDH was 16·5 per 100 000 infants (n = 306). Median age was 2·5 months. For infants older than one week, the median age was 3·5 months. Case fatality was 6·5%. Male sex was overrepresented for all SDH subgroups. Accidental falls were reported in 1/3 of the cases. One-fourth occurred within 0–6 days, having a perinatal risk profile. For infants aged 7–365 days, acute nontraumatic SDH was associated with multiple birth, preterm birth, and small-for-gestational age. Fourteen percent also had an abuse diagnosis, having increased odds of being born preterm, and being small-for-gestational age.ConclusionsThe incidence was in the range previously reported. SDH among newborns was associated with difficult birth and neonatal morbidity. Acute nontraumatic SDH and SDH with abuse diagnosis had similar perinatal risk profiles. The increased odds for acute nontraumatic SDH in twins, preterm births, neonatal convulsions or small-for-gestational age indicate a perinatal vulnerability for SDH beyond 1st week of life. The association between prematurity/small-for-gestational age and abuse diagnosis is intriguing and not easily understood.

Medical diagnoses among infants at entry in out‐of‐home care: A Swedish population‐register study

“…Given that only a small proportion (1.8%) of the infants had superficial injuries of the body indicating violence, it is possible that a considerable proportion of those infants had such underlying medical conditions. This assumption is further supported by the fact that diagnoses of SDH, long bone, and rib fracture that were associated with abuse only constituted a minor part of all those fractures found in the population, as shown in our previous studies …”

“…The Swedish Out‐of‐home Care Register does not contain the actual causes for removing infants from their families; thus, our derivation of specific medical diagnoses from the NPR may not reflect the actual cause for out‐of‐home care. However, the applied diagnoses SDH, RH, rib fracture, or long bone fracture were recorded in accordance with stated knowledge, thus supporting a causal inference …”

“…The high proportion (37%) of fall accidents among those having SDH, RH, rib fracture, or long bone fracture is intriguing. Swedish population data show that fall accidents, mostly with slight or moderate trauma, are reported for 34% of all SDH diagnoses and for 71% of all long bone fractures . However, the diagnostic considerations of abuse while parents have reported a fall accident cannot be addressed by this study design.…”

“…We defined the following perinatal (for the index pregnancy and birth) and parental variables according to current knowledge: Maternal and perinatal information: sex of infant; single/multiple birth, term, or preterm born (<37 gestational week); small‐for‐gestational age (SGA) (<2.5 percentiles); maternal body mass index (BMI) at start of index pregnancy, defining underweight (BMI < 19) or overweight (BMI ≥ 25); and maternal smoking in pregnancy weeks 30 to 32. Sociodemographic information: mother married/cohabiting or single living; maternal age <20, 20 to 34, >35 years; parity 1 and parity 2+; maternal birth country, either the Nordic countries (Denmark, Finland, Iceland, Norway, or Sweden) or outside these countries; and highest level of education for mother and father at time of birth of the index child as basic, secondary, or postsecondary education. …”

“…22 This systematic literature review has been criticized, commented on, and answered by the SBU expert group. [23][24][25][26][27][28][29] We have provided evidence of perinatal risk factor profiles of infants with abuse diagnosis and SDH, 30 rib, or long bone fractures, 31 risk profiles that are similar to those having a medical cause of SDH or fractures.…”