Methodological challenges in the study of fetal growth

Several conceptual and methodological challenges must be solved in order to create knowledge that can be useful to pregnant women, their families, and any clinicians who serve them: (1) going beyond nominal and ordinal hypotheses and presenting estimates of conditional probabilities; (2) focusing on clearly defined outcomes; (3) modeling the relationship of fetal growth and length of gestation; (4) understanding the process of fetal growth even though most of our data is cross-sectional; (5) estimating the independent effects of genetics, race, ethnicity, maternal risk behaviors, medical prenatal care, and socioeconomic status on fetal growth and length of gestation; and (6) estimating the independent effects of maternal pre-pregnancy weight, weight gain during pregnancy, and nutrition on fetal growth and length of gestation. The analysis and writing of this study was funded, in part, by a grant from the National Institute of Child Health and Human Development (NICHD RO1 HD 20511). Troy D. Abell, Ph.D., M.P.H., is associate professor of anthropology and adjunct associate professor of family medicine at the University of Oklahoma. His major interests are in the biocultural determinants of fetal growth and the epistemologic issues inherent in statistical reasoning, scientific inference, and decision analysis.