Association between dynamic asymmetry of the newborn's head and intrauterine factors

A historical, systematic review of handedness origins

Handedness ontogenesis is still under debate in science. This systematic review analyzed articles regarding the theories and basis of handedness formation, highlighting the historical knowledge path that this literature underwent. Cochrane Library, LILACS, Web of Sciences, Science Direct and PubMed databases were searched. This review included review studies with handedness as the main topic. Only papers written in English with analyses exclusively in neurotypical humans (any age range) were included. Different approaches (genetic, neural, social, and behavioural) were reviewed in light of growing evidence, summarizing the current state of the art. Genetic and environmental/social impacts are common points in most of the reviews, each given more or less importance, depending on the author and theory proposed. Multifactorial, developmental approaches to handedness formation seem to be the most up to date view of the phenomenon. Different control mechanisms between hemisphere and neural asymmetries are also contributing factors to handedness formation.

Prevalence and characteristics of positional plagiocephaly in healthy full-term infants at 8-12 weeks of life

Positional plagiocephaly (PP) denotes flattening of the skull that occurs frequently in healthy infants. Aim of this study was to estimate the prevalence of positional plagiocephaly and to identify the risk factors in a cohort of healthy infants in order to help prevention of PP. In a prospective design, all healthy full-term infants, ranging from 8 to 12 weeks of age, who presented at the public immunization clinic in Ferrara, were eligible for the study. After obtaining informed consent, we interviewed the parents and examined the infants using the Argenta's assessment tool. Of 283 infants examined, 107 (37.8%) were found to have PP at 8-12 weeks of age. In 64.5%, PP was on the right side, 50.5% were male and 15% presented also with brachycephaly. Risk factors significantly associated were lower head circumference, advanced maternal age, Italian compared to African, and supine sleep position, in particular for infants born at 37 weeks, preference for one side of the head. In logistic regression, risk factors significantly associated were lower birth weight, advanced maternal age, and supine sleep position.

CONCLUSIONS

Positional plagiocephaly is a common issue faced by pediatricians; our results reinforce the need of improving prevention both of sudden infant death and positional plagiocephaly, through uniform messages provided prenatally and postnatally by different health professionals. "What is Known:" •The incidence of positional plagiocephaly varies due to population studied and measuring methods. •Different factors are considered in the literature as being associated to positional plagiocephaly (infant factors, obstetric factors, infant care practices, sociodemographic factors). "What is New:" •This is one of the few European studies quantifying positional plagiocephaly prevalence in a population of unselected healthy infants. •In this study, positional plagiocephaly is confirmed as a common issue, related to some factor (as supine sleep position and positional head prevalence) that should be addressed in pre and postnatal counseling. •The prone sleepers rate in our population highlight the need to improve parental awareness regarding SIDS prevention, in particular in borderline gestational age.