Handedness in preterm born children: A systematic review and a meta-analysis

• Published in: Neuropsychologia 2011-07, Vol.49 (9), p.2299-2310
• Main Authors: Domellöf, Erik, Johansson, Anna-Maria, Rönnqvist, Louise
• Format: Article
• Language: English
• Subjects: Adolescent; Biological and medical sciences; Case-Control Studies; Cerebrum - growth & development; Cerebrum - physiology; Child; Child development; Child, Preschool; Children; Developmental psychology; Diseases of mother, fetus and pregnancy; Dominance, Cerebral - physiology; Functional Laterality; Fundamental and applied biological sciences. Psychology; Gynecology. Andrology. Obstetrics; Hand preference; Handedness; Humans; Infant; Infant, Newborn; Laterality; Longitudinal Studies; Male; Medical sciences; Odds Ratio; Pregnancy. Fetus. Placenta; Premature Birth; Preterm birth; Psychology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psykologi; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Socialvetenskap
• ISSN: 0028-3932; 1873-3514; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2011.04.033

► Review of non-right handedness (NRH) in preterm compared with fullterm children. ► Meta-analysis (18 studies) shows reliably increased NRH in preterm children. ► Underlying causes for altered handedness in preterm children are still unclear. ► More specific studies using more coherent and sensitive methodologies are warranted. It has been proposed that left and/or non-right handedness (NRH) is over-represented in children with a history of preterm birth because such births are associated with a greater incidence of insult to the brain. We report an approximate two-fold increase in left and/or non-right handedness based on a systematic search of the literature from 1980 to September 2010 for English-language articles reporting handedness status in preterm children compared with fullterm controls either as a main focus of the study or as a secondary finding. In total, thirty articles met the inclusion criteria. However, there was a great variation between the included studies in terms of objectives, population characteristics, sample size and methodologies used. While the majority of studies reported a higher incidence of NRH in preterm than fullterm children, this was not a consistent finding. A quality assessment was made to explore the differences in overall study quality and handedness assessment methodology between studies. A random-effects model meta-analysis was then performed to estimate the accumulated effect of preterm birth on handedness (18 studies; 1947 cases and 8170 controls). Preterm children displayed a significantly higher occurrence of NRH than fullterm children (odds ratio [OR]: 2.12; 95% confidence interval [CI]: 1.59–2.78). Sources of heterogeneity were investigated by supplementary meta-analyses considering studies with high or low overall and handedness assessment quality. Publication bias was assessed by Egger's test of the intercept and Duvall and Tweedie's trim-and-fill method. The outcomes of these procedures did not jeopardize the overall finding of reliably increased OR for NRH in preterm children. The present review suggests that a preterm birth is indeed associated with a greater than two-fold likelihood of NRH. Several studies also explored the relationship between handedness and neuropsychological functioning (cognition mainly) with an array of methods. Although not without disagreement, this association was found to be concordant. Studying handedness in preterm children, therefore, is a potentially important index of hemi