Data are presented on 157 newborn infants followed sequentially in a random
ized home-based nursing-intervention trial for drug-exposed infants with fo
llow up at 3 (N=118), 6 (N=124), and 12 months (N=77). The objectives of th
is study were to describe the longitudinal neurodevelopmental status of a c
ohort of children with intrauterine exposure to illicit drugs during their
gestation, characterize the evolution of early tone abnormalities in a poly
drug-exposed cohort, and determine whether neuromotor outcome is associated
with drug-exposure patterns. For analysis, infants were grouped based on m
aternal drug-use pattern and the presence of drug metabolites in the neonat
al drug screen. The sequential neuromotor examination was used at each age
to define the neuromotor status of six domains and define categorical class
ifications as either normal, suspect, or abnormal. Multiple patterns of neu
romotor abnormalities were observed during the neonatal period; most resolv
ed over time. Axial hypotonia was a prominent finding in the neonatal perio
d; however, it was infrequent in abnormal examinations at 12 months. Increa
sed lower-extremity tone was a less frequent finding during the neonatal pe
riod. Infants whose neonatal urine drug screen was positive for both cocain
e and opiates, were more likely than infants with negative urine drug scree
ns, cocaine only, or opiate only drug screen results to have abnormal neuro
motor examinations; while positive maternal drug screens for concurrent coc
aine and opiate use were associated with peripheral hypertonia. Persistence
of increased leg-extensor tone was found in 67% of the abnormal examinatio
ns at 12 months. Acquisition of rolling and walking was delayed in the drug
-exposed cohort.