Cocaine-exposed preterm neonates show behavioral and hormonal differences

Abstract

Objective: Prematurity has been associated with prenatal cocaine exposure, but most studies on the behavioral effects of prenatal cocaine exposure have been restricted to full-term infant samples. The current study focused on behavioral and hormonal responses in preterm cocaine-exposed infants compared with a cohort of non-cocaine-exposed infants of similar gestational age.

Methodology: A comparison between 30 cocaine-exposed and 30 non-cocaine-exposed preterm neonates suggested that the cocaine-exposed neonates were born to mothers who had higher parity and more obstetric complications. In addition, mothers of cocaine-exposed preterm neonates visited, touched, held, and fed their infants less frequently than mothers of nonexposed infants.

Results: The cocaine-exposed infants had smaller head circumferences at birth, spent more time in the neonatal intensive care unit, and had a greater incidence of periventricular-intraventricular hemorrhages. They also had inferior Brazelton cluster scores, including lower state regulation and range-of-state scores, and greater depression. During sleep-wake behavior observations, they showed difficulty maintaining alert states and self-regulating their behavior, and they spent more time in indeterminate sleep and had decreased periods of quiet sleep and increased levels of agitated behavior, including tremulousness, mouthing, multiple limb movements, and clenched fists. Finally, higher urinary norepinephrine, dopamine, and cortisol levels and lower plasma insulin levels were noted in the cocaine-exposed preterm neonates.

Conclusions: These findings highlight the need for follow-up assessments and early intervention.