Abstract
The mean birth weight of the 1586 probands with clefts who were born in Finland between 1975 and 1985 was 3346 g, which is lower than the mean of all live born babies in 1980 (3541 g). The 345 who had an associated anomaly or syndrome had a mean birth weight of 3 027 g and placental weight of 538 g, compared with 3435 g and 609 g, respectively, for those with solitary clefts. The more severe the cleft the lower the birth weight, but not the placental weight. The percentage of low birthweight (≤2500 g) infants was higher than in the general population (8.5% compared with 3.8%). The highest percentage of low birthweight infants was in the subgroup with bilateral cleft lip and palate (16.8%).