Differences in salivary cortisol levels in cocaine-exposed and noncocaine-exposed NICU infants.

To assess whether cocaine exposure in utero affected adrenocortical responsiveness in the neonatal period, salivary cortisol levels were compared between noncocaine-exposed (n = 35) and cocaine-exposed (n = 11) healthy preterm infants just prior to hospital discharge. Cortisol levels were measured under three conditions: Basal--120 min after no disrupting event or behavioral distress; Noninvasive Stressor--30 min after a neurobehavioral examination; Invasive Stressor--30 min after a heel-stick procedure. There were no differences in Basal cortisol levels between the noncocaine-exposed and cocaine-exposed infants, but the cocaine-exposed infants had significantly lower levels in both the Noninvasive and Invasive Stressor conditions. The suppressed cortisol responding to stressful events in cocaine-exposed infants suggests that these infants may have decreased modulation capability to normally stressful events, which could underlie some of the subtle state regulation problems reported.