How prevalent is being born small for gestational age? Analysis of 7341 children from the ELSPAC study population
Abstract
Intrauterine growth restriction that results in lower birth weight and/or birth length (SGA, small for gestational age) is linked to increased risk of perinatal morbidity andmortality, short stature in childhood and adulthood andmay increase risk of cardiovascular diseases and type 2 diabetes. Published data on the frequency of newborns assigned as SGA vary according to SGA definition and to the method and accuracy of gestational age estimation.
We aimed to analyze the impact of methodology of gestational age estimation on frequency of SGA in children of the Moravian branch of the internationalmulticentre study ELSPAC (European Longitudinal Study of Pregnancy and Childhood) and to compare the results with international reference values. The study included 7533 children born in the city of Brno and in the Znojmo district within 16months in 1991-1992.
Majority of essential data were available in 7341 of them. We proved that method of estimation of gestational age substantially modifies the population frequency of SGA, ranging from 5.3% in ultrasound method and 6.8% in estimation according to last menstrual period up to 13.8% according to reported data (as given in the questionnaire).
Birth weights and birth lengths of children in the ELSPAC study were compared with international reference data according to Lawrence (1989). Whereas similar results were found at gestational ages 34-36 weeks, values at gestational ages 37-42 weeks were significantly lower in the ELSPAC population.
Due to a smaller sample size of the ELSPAC cohort, we recommend using the international reference normative data in clinical praxis, however interpretation of individual values should be based on estimation of gestational age according to ultrasound or last menstrual period.