Birth Weight, Lenght and Head Circumference Percentiles by Gestational Age and Gender of Term Neonates in Tuzla Canton

Background: In University Clinical Center, Department of Obstetrics and Gynaecology is using reference data from 1974 developed for the infants born in Belgrade (Serbia). It estimates the standards of term infants for neonatal weight, length and head circumference. Aim: This study was create to develop charts for birth weight, lenght and head circumference specific to gestational age, gender and parity for term singleton infants in Tuzla Canton. Methods: The study was conducted at University Clinical Center Tuzla, Department of Obstetrics and Gynecology, a primary obstetrical care facility for residents of Tuzla Canton over the one-year period. During the one year study period, 01.01.- 31.12.2009, there were 4106 infants born at 37th to 41th weeks of gestation (GW), 2168 (52.8 %) males and 1938 (47.2%) females. We analysed gestational age, birth weights, body length and head circumference. Results: Females infants of primiparae, born at 40th gestational week, had the lowest median birth weight, 3500 g, followed by female infants of multiparae, 3640 g, and male infants of primiparae, 3650 g. The greatest median birth weight, 3730 g, had male infants of multiparae. Median birth length value at the 40th gestational week for male infants of primiparae and multiparae, as well as female infants of multiparae is the same, 55 cm, while is lower in female infants of primiparae (54 cm). There is no difference in median head circumference at the 40th gestational week between female infants of primiparae and multiparae, and male infants of primiparae (35 cm). Mean birth weight and length of liveborn infants at 37. to 41. gestational week differed significantly between certain parities (F=8,723, Df=2, p<0,001; F=3,292, Df=2, p=0,037, respectively). No significant difference was found for head circumference (F=0,983, Df=2, p=0,374). Conclusion: The average birth weight of infants within Tuzla Canton is bigger in comparison with the centile that have been used so far.