The effect of gestational age errors and their correction in interpreting population trends in fetal growth and gestational age-specific mortality.

In perinatal research and clinical practice, gestational age is a crucial variable for measuring fetal "growth" (birth weight for gestational age) and for estimating the risk of mortality and morbidity. Yet, reported gestational age values are affected by random and systematic errors. This article reviews methods for detecting and correcting errors in gestational age and compares the effects of these methods on fetal growth standards and on the use of population-based data in analysis of trends in gestational-age specific infant mortality.