Adverse neurodevelopmental outcome in childhood after moderate and late preterm birth

Event start date
Event start time
12.00
Place

Arvo building, auditorium F114, address: Arvo Ylpön katu 34.

Mikko Hirvonen

Doctoral defence of Lic.Med. Mikko Hirvonen

Adverse neurodevelopmental outcome in childhood after moderate and late preterm birth : A nationwide register study

The field of science of the dissertation is Paediatrics.

The opponent is professor Leena Haataja (University of Helsinki). Professor Kalle Kurppa acts as the custos.

The language of the dissertation defence is Finnish.

Neurodevelopmental outcome afterm moderate and late preterm birth

Moderate and late preterm infants have a greater risk of neurodevelopmental disabilities

According to a large Finnish national register study (Adverse neurodevelopmental outcome in childhood after moderate and late preterm birth – A nationwide register study) both moderately preterm (32-33 gestational weeks) and late preterm (gestational weeks 34-36) infants were at a greater risk of neurodevelopmental disabilities compared with infants born at term (more than 37 gestational weeks). Moderate and late preterm children had a greater risk of developing cerebral palsy, epilepsy, and sensory impairments than children born at term, but the risk of intellectual disability did not differ between any of these groups. The most prominent risk factors for the development of disabilities were intracranial hemorrhages and convulsions during the neonatal period. Smoking during pregnancy also predicted an increased risk of disabilities in childhood.

According to this study, the incidence of cerebral palsy (CP) was 24-fold in children born between the gestational weeks 32 and 33, and six-fold in children born between weeks 34 and 36, in comparison to children born at term.  Moderate and late preterm children also had an increased risk of epilepsy and sensory disabilities in comparison to children born at term.

The national register study included all of the children born in Finland between 1991 and 2008 as per data obtained from the Medical Birth Register. Infants with missing data on gestational age, those with any major congenital malformations, and those who died before the age of one year were excluded. The remaining 1,018,256 infants constituted the population of the study. Incidences of CP, intellectual disability, epilepsy, and sensory impairments in childhood were assessed by linking the health register data. The purpose of this study was to compare the incidences of long-term neurodevelopmental disabilities in moderate and late preterm children to those in very preterm (born at <32 gestational weeks) and at term children.
 
Neurodevelopmental impairment is a marked, long-term complication in children born preterm, and the risk is highest among the most prematurely born infants. Moderate preterm and late preterm infants form the majority (more than 80%) of all prematurely born infants, and morbidity in this group presents a burden on individuals, families, and the healthcare system. Thus, it is essential to evaluate the long-term consequences of moderate and late preterm births, and to establish potential factors predictive of long-term neurological morbidity.

In this large national register study, we found that moderate and late preterm infants are at an increased risk of CP, epilepsy, and visual disturbances or blindness in childhood in comparison to children born at term. No previous large register-based studies exist that focus on the long-term neurodevelopmental outcomes of moderate and late preterm children in Finland, even though these children comprise the majority of all prematurely born children. Furthermore, there are only a few, earlier, national studies worldwide that have focused on the same issues as the present study.

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The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2374, Tampere University Press, Tampere 2018. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1880, Tampere University Press 2018.

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