Objective-To measure the prevalence of breast feeding and to examine t
he value of using information collected on Guthrie cards (used for det
ecting inherited metabolic disease and hypothyroidism when newborn inf
ants are 7 days old) to calculate this prevalence. Design-Analysis, by
geographical area and maternity unit, of information on breast feedin
g collected on Guthrie cards for 131 759 babies born 1990 and 1991, an
d comparison with prevalences from other sources. Setting-Scotland. Re
sults-Of the 131 759 babies, only 46 949 (35.6%) were breast feeding o
n day 7. The prevalence of breast feeding ranged from 59.1% (376/636)
in Shetland to 21.1% (1836/8719) in Lanarkshire and < 8% in some postc
ode districts of cities. Analysis of the data by hospital of birth sho
wed that the prevalence ranged from 51.2% (2701/5275) to 16.4% (507/30
90). Conclusion-The prevalence of breast feeding in Scotland is low an
d varies among areas and maternity units. Intervention to increase thi
s prevalence is essential, and information collected on Guthrie cards
is a useful indication of mothers' intentions to breast feed.