Sucking rates of human babies on the breast; a study using direct observation and intraoral pressure measurements

Sucking patterns of human babies on the breast were recorded using intraoral pressure measurements and direct observation. In a comparison of the presence or absence of sucking on each record for consecutive 2-sec periods, the records concurred 92% of the time; the contingency coefficient was 0.65; X2 was 1156.2, p<0.001. In a comparison of the number of sucks recorded by the two methods in each burst correlations (rs) between the two for individual babies ranged from 0.82 to 0.99, with p<0.001 in each case. Both methods showed that intersuck intervals on the breast vary from 0.5 to 1.3 sec around a single mode of 0.7–0.8 sec. There is no distinction into two rates of sucking, nutritive and non-nutritive, but rather a continuous grading between the two.