Reference Curves of Birth Weight, Length, and Head Circumference for Gestational Age in Iranian Singleton Births

Background: Growth charts have been used to record and evaluate an infant's growth condition at birth and during infancy. The current study was undertaken to explore the anthropometric indices of growth in Iranian newborn infants to draw growth charts and compare them with charts in use. Methods: Data of singleton births was extracted from the Iranian national data centre ministry of health database between March 2 014 and 2015. Newborns with ill conditions, stillbirth, congenital anomalies such as neural tube defects (NTD5), and multiple births were excluded. Our study included 1277169 singleton live births. Growth curves were created for boys (51.7%) and girls (48.2%) for birth weight, length, and head circumference. Smoothening of the curves was accomplished by using gamlss package under R.3.0.1 software. Results: The average GA was 38.5 +/- 1 weeks. The average birth weight was 3242 +/- 422 gram and 3125 +/- 422 gram for boys and girls respectively. Length of body at birth was 50 +/- 2.2 cm in boys and 49.5 +/- 1.2 cm in girls and as for head circumference, the average was 35 +/- 1.4 cm and 34.2 +/- 2.3 cm respectively for studied boys and girls. Female newborns had lower weight, length and head circumference in comparison to male newborns. Conclusions: we observed differences between age-gender specific growth chart in Iranian newborn infants with Fenton growth chart that maybe attributed to ethnicity, regional and socioeconomic factors, mother-fetus health and nutrition status during pregnancy