Palpable spleens in newborn term infants

Spleen tip size was determined in 470 full-term appropriate-for-gestational-age infants within the first 24 hours of life. The spleen was palpable in 17.9 percent of them. It was palpated less than 1 cm below the costal margin in 11.7 percent, between 1 and 2 cm in 3.6 percent, and 2 cm or more in 2.6 percent. No cause for spleen enlargement was found except in two infants with ABO hemolytic disease.