Spanish cross-sectional growth study 2008. Part I: Weight and height values in newborns of 26-42weeks of gestational age

Introduction: Gestational age and neonatal anthropometric parameters are related to neonatal and postnatal morbidity and mortality. Subjects and methods: Weight and vertex-heel length were evaluated in 9.362 caucasian newborns (4.884 males and 4.478 females) products of single pregnancies, 26-42 weeks of gestational age, born between 1999 and 2002 in Vall d'Hebron (Barcelona, Spain) and Miguel Servet (Zaragoza, Spain) Children's Hospitals. Results: Mean and standard deviation and percentile distribution values of weight, and length according to sex and gestational age are presented. A progressive increase in these parameters with gestational age and a sexual dimorphism was observed from the 30 week of gestational age onwards, with statistically-significant differences (p < 0.01) from 35 weeks of gestational age. At 38 and 42 weeks of gestational ages these differences were 170 g, 160 g, 0,8 cm and 0,9 cm respectively. An increase in weight and length values in relation to previous Spanish studies (1987-1992) was also documented. Conclusions: A sexual dimorphism in intrauterine anthropometric growth parameters was observed. These parameters change with time and may be updated.