Transplacentally acquired caffeine and the occurrence of apnea, bradycardia, and periodic breathing in preterm infants: preliminary communication.

Cord blood caffeine concentrations were measured by high-pressure liquid chromatography in 79 preterm infants. Eleven infants (14%) had detectable caffeine concentrations ranging from 1.1 to 3.7 micrograms/mL (means +/- SD = 2.5 +/- 0.8), and 68 infants had no measurable caffeine. Seven infants with detectable caffeine (group 1) had impedance pneumograms recorded before 2 weeks of age. Each infant in group 1 was matched with two infants without detectable caffeine by birthweight, gestational age, and chronologic age at pneumogram recording to yield a control group (group 2) of 14 infants. Comparison of the groups using quantitative measures of apnea, bradycardia, and periodic breathing obtained from pneumogram analysis and the incidence of monitor alarms on bedside nursing records showed no significant differences. Thus, caffeine was present infrequently and at low concentrations at birth in 79 preterm infants. The amount of apnea, bradycardia, and periodic breathing experienced before 2 weeks of age in 7 preterm infants with detectable cord blood caffeine was not different from that in 14 similar infants without caffeine. Future studies are planned to examine the relationship between postnatal changes in transplacentally acquired methylxanthine concentrations and quantitative measures of apnea, bradycardia, and periodic breathing in a larger number of preterm infants without cardiorespiratory disease.