Body height differentiation by season of birth: Girls from Cracow, Poland

Abstract

Body height differentiation by season of birth: Girls from Cracow, PolandPublished studies world wide demonstrate that measures of human development and health status vary depending on the month of birth but these patterns are not always consistent and sometimes even conflict. Direct factors related to the birth season that may significantly differentiate morphological and functional traits and mechanisms causing these relations have not been found so far. On the basis of cross-sectional material, gathered in the years 1983 and 2000 by the Department of Anthropology of the Academy of Physical Education in Cracow, two main hypotheses have been verified: (1) average body height differences by month of birth are statistically insignificant, (2) the magnitude of these differences does not change with time. Metric data of 4672 girls aged 5-18 years, born in 1965-1978 and 1982-1995, were used. The total sample was also subdivided into prepubertal (5-9 years) and adolescent (10-18 years) groups. The age of the individuals was calculated to the nearest day and the procedure of standardization on the interpolated values of regional norms was applied. A highly significant relationship between the birth month and average values of height was revealed in preadolescent girls. The results obtained for the entire material proved insignificant. The patterns of the month-of-birth effect on body height for girls born in 60./70. and 80./90. show high similarity, though the effect seems weaker in the latter sample. Winter proved to be the most favorable birth season for later body height.

Seasonal Variations of Neuromotor Development By 14 Months of Age: Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

“…Similarly, winter-born children have been reported to grow fastest in terms of height during childhood [10], [11]. On the other hand, another study reported that the growth in height of infants speeds up during the summer months, irrespective of month of birth [12].…”

Birth month associations with height, head circumference, and limb lengths among peruvian children

“…Associations have been widely reported between season of birth and a range of characteristics, including birth weight and length (Wohlfahrt et al, ; McGrath et al, , ; Torche and Corvalan, ; Krenz‐Niedbała et al, ) and body size in childhood (Kościński et al, ; Puch et al, ) and adulthood (Weber et al, ; Waldie et al, ). Season of birth associations with phenotype and health in developing countries are thought to reflect seasonal variation in diet, activity, and disease (Roberts et al, ; Adair and Pollitt, ; Moore et al, ; Rayco‐Solon et al, ; Chodick et al, ).…”

“…Associations between birth month and body size persist into adulthood, suggesting that observed differences have their origin in prenatal or early postnatal life when growth trajectories are particularly sensitive to the environment (Smith et al, ; Lucas, ; Martorell et al, ; Schroeder et al, ; Mei et al, ; Dewey and Adu‐Afarwuah, ; Stein et al, ). While patterns may be expected to persist through childhood, studies investigating child height or body mass in relation to birth season provide mixed results in terms whether any patterns are observed, at what ages they are found, and when in the year the peaks and nadirs fall (Shephard et al, ; Henneberg and Louw, ; Waldie et al, ; Kościński et al, ; McGrath et al, ; Tanaka et al, ; Puch et al, ). This may in part relate to the fact that environmental factors like sunlight exposure or day length have separate effects on growth in childhood which may mask or modify patterns arising form birth season (Waldie et al, ).…”

Season of birth influences the timing of first menstruation

“…Comparing the age at menarche for subjects born in the summer months and in other months, the differences are statistically significant in both cohorts. Other studies carried out in Poland show that children born in the summer are characterized by inferior biological growth parameters in the early stages of their lives, as in linear enamel thickness ( _ Za˛dzi nska et al, 2013), body height (KrenzNiedbała et al, 2011;Puch et al, 2008), and body mass (Ko sci nski et al, 2009). In contrast, a study conducted by Siniarska and Kozieł (2010) showed that the birth length of boys is greatest in October and lowest in March and that in the first semiannual period the neonates are shorter than in the second (Siniarska and Kozieł, 2010).…”