Risk factors for quantity not sufficient sweat collection in infants 3 months or younger

The purpose is to identify demographic characteristics associated with a quantity not sufficient (QNS) sweat collection in infants 3 months or younger.

History of premature birth, infant race and sex, gestational age at delivery, and weight of the infant were compared with QNS collection.

Of 221 sweat collections from 197 infants, 25 were QNS. Infant weight less than 3 kg and history of prematurity were associated with QNS collection (P < .001). Thirteen (30.2%) of 43 infants weighing less than 3 kg had QNS collections compared with 12 (7.9%) of 151 infants 3 kg or more. Twelve (46.2%) premature infants had QNS collections compared with 13 (7.6%) term infants. Lower birth gestational age and corrected gestational age were associated with QNS collections. Six (86%) of seven infants who weighed less than 3 kg, had a history of prematurity, and were more than 54 days old at testing had a QNS result. Sex and race did not correlate with QNS collections.

Weight less than 3 kg and history of prematurity are associated with an increased chance of QNS sweat collections.