[Study on height-weight indices in newborns of different gestational ages].

ABSTRACT

OBJECTIVE: To establish height-weight indices in newborns of different gestational ages and to provide reference data for evaluation of intrauterine fetal growth. METHODS: The weight, height, crown-rump length, head circumference, and chest circumference of 8 357 newborns were measured in Maternal and Child Health Care Hospital of Bao'an District of shenzhen between 2005 and 2006, with the method of fact-finding investigation with cross-sectional cluster sampling, to establish the height-weight indices in newborns of different gestational ages. RESULTS: Five gender-specific height-weight indices (Quetelet Index, QI; Kaup Index, KI; Rohrer Index, RI; Livi Index, LI; Polock Index, PI) in newborns of different gestational ages (28-44 weeks of gestation) in three different groups (boys+girls, boys, and girls) were established in Shenzhen, China, and were expressed as mean gestational weeks±SD. The five indices above all increased with increasing gestational age, and the highest values appeared at 41-43 gestational weeks, suggesting that body density and enrichment degree increased constantly with increasing gestational age. Three indices (QI, KI and PI) were higher in boys than in girls (P<0.05). CONCLUSIONS: With the increasing gestational age, the body density and enrichment degree of newborns increase, and the enrichment degree in boys is better than that in girls.