Caffeine exposure in utero increases the incidence of apnea in adult rats

Caffeine abuse during pregnancy may be a factor in the development of long-term breathing abnormalities. Therefore, the objective of the present study was to monitor adult breathing patterns after in utero exposure to caffeine. This was done by isolating episodes of apnea of more than 6-s duration from the breathing data as obtained by the Cotwatch^® breathing monitors adapted for rat use. The breathing record obtained over 6 consecutive days was expressed as daily weighted apnea-hypopnea density (WAHD) values. It was shown that administration of caffeine in moderate (30 mg/kg daily) or high (60 mg/kg daily) doses throughout gestation resulted in a significant dose-dependent increase in the WAHD value. The experimental offspring were significantly growth retarded in utero and their subsequent growth rates were also affected. The caffeine-exposed pups grew more slowly with growth plateauing at the same age, resulting in smaller adults. A link was suggested between infants with apnea of prematurity, when occuring after the first week, and an increased risk for later apnea and sudden infant death syndrome.