Incidence and clinical characteristics of perinatal arterial ischemic stroke in preterm and term born infants – CRC corrected active surveillance data from Germany 2015 – 2017

Introduction:

Due to different case definitions, case ascertainment methods or unrepresentative sampling frames, the incidence estimates for perinatal arterial ischemic stroke (PAIS) differ widely. Valid incidence estimates may be reached through population-based data, validated for completeness.

Though several studies report a high proportion of preterm born infants in patients with PAIS, there are no data comparing incidence, risk profile and clinical presentation to term born infants.

Hence this study aims to answer following questions: what is the true incidence rate of PAIS in Germany? Are there differences in incidence regarding preterm and term birth? Are there differences in risk factors and clinical presentation, comparing preterm and term born infants?

Methods:

Case ascertainment was based on active surveillance in pediatric hospitals in Germany, carried out by ESPED (German Pediatric Surveillance Unit). Newborns with PAIS notified by the treating pediatricians between 2015 and 2017 were included. Detailed information was given by the pediatricians with a study-specific questionnaire, to be extracted from medical records. Incidence rates were estimated by a 2-source capture-recapture calculation (CRC) based on ESPED reports and on hospital discharge records of pediatric hospitals of North-Rhine-Westphalia (NRW). All reports were validated by a team of specialized pediatricians according to the questionnaires and hospital discharge letters.

Results:

160 infants were reported in the 3-year period, 15.6% of these were born premature. The CRC was based on all ESPED reports from NRW (n = 29); 18 additional cases were identified in the hospital discharge database in NRW. 8 cases were reported in both sources. The CRC yielded a total number of 89 cases in NRW (95%CI 50.9 – 127.1), resulting in an incidence rate of 17.6 (95%CI 10.1 – 25.1) per 100,000 live births. The incidence in preterm born infants was 25.8 (95%CI 7.4 – 44.1) per 100,000 premature babies, in term born infants 16.0 (95%CI 8.9 – 23.1) per 100,000 mature babies.

We would expect 12 out of 160 PAIS cases to be born prematurely, at a general preterm birth rate of 8.5% in Germany. Observed (n = 25) compared to expected number (n = 12) of premature cases, provides a standard incidence ratio of 2.1 (95%CI 1.4 – 3.0), hint to an increased risk of PAIS for preterm born infants.

No differences in specific risk factors could be identified between preterm and term born infants, but the number of risk factors was higher in prematures. Term born infants presented more frequently with seizures, whereas in premature infants unspecific symptoms were predominant. Preterm born infants were older at the time of diagnosis than the term born ones.

Discussion:

This study provides valid incidence rate estimates for PAIS in Germany. The higher risk in premature infants and the differences in clinical presentation needs confirmation in further studies. Increased awareness of PAIS in preterm born infants appears warranted.