The trajectory of general movements from birth until 12-14 weeks corrected age in preterm infants born before 33 weeks' gestation and weighing less than 1500g : a descriptive study

Van Zyl, Reze (2019-04)

Thesis (MScPhysio)--Stellenbosch University, 2019.

Thesis

ENGLISH SUMMARY : Background: Preterm infants remains a high risk group for developing neurological deficits such as cerebral palsy (CP). Early identification is important for timely intervention. Tygerberg Children’s Hospital (TCH) is a public hospital with limited resources. It is the biggest neonatal service in the Western Cape. Clinicians depend on a reliable screening method to identify high risk infants in order to allocate resources effectively. Prof. Heinz Prechtl and his co-workers introduced a quick, inexpensive, non-invasive method with high predictive validity for the early detection of those premature infants at risk for later developmental deficits. This method, called general movements (GMs), is based on the assessment of spontaneous movement patterns in young infants. There is limited information available describing the trajectory of GMs in high risk premature infants. Oojective: To describe the trajectories of GMs from birth till 12-14 weeks corrected age and determine the association of known perinatal risk factors on GM trajectories in very low birth weight and extremely low birth weight preterm infants admitted to the neonatal intensive care unit of TCH, Cape Town, South Africa. Methodology: A longitudinal, prospective cohort study with repeated measures was conducted using Prechtl’s method of the qualitative assessment of GMs at the following four key time periods: birth to 33 weeks postmenstrual age (PMA), 34-37 weeks PMA, term age and 12-14 weeks corrected age. Detailed perinatal data of infants were collected. Results were analysed using STATA version 14, IBM SPSS and a logistic regression model to determine the association between perinatal factors and GM outcome. Results: The study sample consisted of 119 infants with a mean birth weight of 1048.2g and a mean gestational age of 28.6 weeks. Of 300 GM assessments done, 157 were preterm assessments, 55 at term age and 88 at 12-14 weeks corrected age. At birth to 33 weeks PMA, 96% of GMs were abnormal and 4% normal. At 34-37 weeks PMA, 89% of GMs were abnormal and 11% normal. All GMs were abnormal at term age. At 12- 14 weeks corrected age, 7% of GMs were abnormal and 93% normal. On univariable analysis, lower birth weight (p=0.043), lower gestational age (p=0.017), intraventricular haemorrhage (IVH) grade IV (p<0.001) and time (PMA in weeks) (p<0.001) were associated with abnormal GMs. Birth weight (p=0.046) and time (PMA in weeks) (p<0.001) were the only variables inversely associated with abnormal GMs on multivariable analysis. Conclusion: The results of this study indicated that GMs are predominantly abnormal prior to term age with a significant decrease in abnormality at 12-14 weeks corrected age. Assessment of preterm and term GM trajectories does not necessarily enable earlier identification of infants at risk for neurodevelopmental difficulties. It is thus not advised that resources be allocated to conduct preterm and term GM trajectories at TCH. Lower birth weight and lower PMA (time) were associated with increased odds for abnormal GMs. Infants with a lower birth weight should be targeted for more frequent follow up and neurological assessments as they remain the most at risk group for neurological deficits. Research on GM trajectories prior to term age and the association of risk factors with long term neurodevelopmental outcome is necessary for future comparison.

AFRIKAANSE OPSOMMING : Agtergrond: Premature baba’s het ‘n hoë risiko vir die ontwikkel van neurologiese afwykings, soos serebrale verlamming, en is afhanklik van vroeë identifisering en intervensie. Hulpbronne by Tygerberg Kinderhospitaal is beperk dus is klinici afhanklik van betroubare metodes van identifisering van hoë risiko baba’s. Prof. Heinz Prechlt en sy medewerkers het ‘n vinnige, bekostigbare en nie-indringende metode met goeie voorspellings vermoë ontwerp, om baba’s met ‘n risiko vir neurologiese aantastings, op ‘n vroeë stadium te identifiseer. Hierdie metode is gebasseer of observasie van spontane bewegings en is ideaal vir gebruik in ontwikkelende lande waar hulpbronne skaars is. Daar is tans beperkte informasie beskikbaar oor die patroon van spontane bewegings voor volterm ouderdom asook die invloed van perinatale risikofaktore op hierdie bewegings. Doel: Om die koers van algemene bewegings vanaf geboorte tot 12-14 weke gekorrigeerde ouderdom, asook die effek van perinatale risikofaktore op die koers, te bepaal in baie lae geboortemassa en uiters lae geboortemassa premature baba’s, opgeneem in die neonatale intensiewe eenheid van Tygerberg Kinderhospitaal, Kaapstad, Suid Afrika. Metodologie: ‘n Longitudinale, prospektiewe kohortstudie is uitgevoer deur Prechtl se metode van kwalitatiewe evaluaring van algemene bewegings tydens die volgende sleutel periodes toe te pas: geboorte tot 33 weke postmenstruele ouderdom, 34-37 weke postmenstruele ouderdom, volterm ouderdom asook 12-14 weke gekorrigeerde ouderdom. Gedetaileerde perinatale data is ingesamel. Resultate is deur middel van STATA weergawe 14 en IBM SPSS geanaliseer. ‘n Logistieke regressie model is gebruik om die assosiasie tussen algemene bewegings uitkomste en perinatale risikofaktore te bepaal. Resultate: Die studiegroep het bestaan uit 199 baba’s met ’n gemiddelde geboortemassa van 1048.2g en gemiddelde gestasie ouderdom van 26.7 weke. Van die 300 algemene bewegings assesserings is uitgevoer waarvan 157 preterm assesserings was, 55 tydens volterm en 88 tydens 12-14 weke gekorrigeerde ouderdom. Tydens geboorte tot 33 weke postmenstruele ouderdom, was 96% van die assesserings abnormaal en 4% normaal. Tydens 33-37 weke postmenstruele ouderdom was 89% van assesserings abnormal en 11% normaal. Alle assesserings was abnormaal tydens volterm assesserings. Tydens 12-14 weke gekorrigeerde ouderdom was 7% van assesseings abnormaal en 93% normaal. Met eenveranderlike anallise was laer geboortemassa (p=0.043), laer gestasie ouderdom (p=0.017), graad IV intraventrikulêre bloeding (p<0.000) asook tydsverloop (p<0.000) geassosieer met abnormale algemene bewegings. Tydens meerveranderlike analise was slegs geboortemassa (p=0.046) en tydsverloop (p,0.000) omgekeerd geassosieer met abnormale algemene bewegings. Gevolgtrekking: Die resultate van die studie dui daarop dat algemene bewegings tydens die preterm tydperk hoofsaaklik abnormaal is, maar grootliks normaliseer teen 12-14 weke gekorrigeerde ouderdom. Dit is dus nie aanbevole dat hulpbronne op preterm beweging assesserings spandeer word nie. Lae geboortemassa en ‘n korter tydsverloop vanaf geboorte was geassosieer met ‘n grooter kans op abnormale algemene bewegings. Verdere navorsing in preterm algemene bewegings koerse en later ontwikkelingsuitkomsye is nodig vir toekomstige vergelykings.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/106038
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