The birth weight and gestational age of 1368 newborns with isolated cleft lip with or without cleft palate and 582 with isolated cleft palate were compared to those of matched healthy controls. The results indicate that fetuses with oral clefts are at elevated risk of having low and very low birth weight, but not of having a premature birth. Speculations on a relationship between these findings and the presence of oral clefts are presented.