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

Abstract

Associations between season of birth and body size, morbidity, and mortality have been widely documented, but it is unclear whether different parts of the body are differentially sensitive, and if such effects persist through childhood. This may be relevant to understanding the relationship between early life environment and body size and proportions. We investigated associations between birth month and anthropometry among rural highland (n 5 162) and urban lowland (n 5 184) Peruvian children aged 6 months to 8 years. Stature; head-trunk height; total limb, ulna, tibia, hand, and foot lengths; head circumference; and limb measurements relative to head-trunk height were converted to internal age-sex-specific z scores. Lowland and highland datasets were then analyzed separately for birth month trends using cosinor analysis, as urban conditions likely provide a more consistent environment compared with anticipated seasonal variation in the rural highlands. Among highland children birth month associations were significant most strongly for tibia length, followed by total lower limb length and stature, with a peak among November births. Results were not significant for other measurements or among lowland children. The results suggest a prenatal or early postnatal environmental effect on growth that is more marked in limb lengths than trunk length or head size, and persists across the age range studied. We suggest that the results may reflect seasonal variation in maternal nutrition in the rural highlands, but other hypotheses such as variation in maternal vitamin D levels cannot be excluded. Am J Phys Anthropol 154:115-124,

Birth month and risk of atopic dermatitis: a nationwide population-based study

“…This explanation might be one of the etiologic factors of this complex disease . In addition, maternal exposure to dry climate in the birth month may influence the fetal reactions that increase the possibility of having dry skin in the early infancy . However, this hypothesis needs more data and future further studies.…”

Nutrition Smoothing: Can Proximity to Towns and Cities Protect Rural Children against Seasonal Variation in Agroclimatic Conditions at Birth?

“…Households that rely on agriculture for income and food may be most susceptible to climate variation and most unable to smooth consumption across seasons [45–47]. Anthropological evidence from Peru suggests that these fluctuations may be greatest for the most isolated rural households [48], but in other settings such as Bangladesh, even city-dwellers may experience seasonal shifts in food security and child weight-for-age [49]. …”

Effect of the month of birth on the height of young adult males

“…The effect of month of birth on human height has been examined in a number of studies. Although, in general, these studies tend to report that individuals born in spring and summer are taller (Henneberg & Louw, ; Weber, Prossinger, & Seidler, ), results vary enough across studies and definite conclusions cannot yet be drawn (Pomeroy et al, ; Rosset, Żądzińska, Strapagiel, Grzelak, & Henneberg, ; Sohn, ). The aim of the present study was to explore a possible association between the month of birth and the final adult height in men and see if this could be described in terms of periodicity.…”