1. Developmental Outcomes in Infants of Opiate Addicted Women: Effects on Cognitive and Motor Development
B.A. Logan, N.A. Heller, D.G. Morrison, H. Shrestha, and M.J. Hayes 
Department of Psychology & Graduate School of Biomedical Sciences, University of Maine, Orono, ME 04469
Background
Method
Methadone replacement is the standard of care for opiate-addicted pregnant women, although few studies have characterized the long-term sequelae of early exposure. Women maintained on methadone often present with a number of other risk factors, including socioeconomic disadvantage and alcohol use. The aim of this study is to examine the contributory role of alcohol on cognitive and motor processes in an opiate-exposed during the first year of life.
Participants: As part of a larger longitudinal study, rural, disadvantaged mothers (N=141) maintained on methadone during pregnancy and comparison controls were recruited from local narcotics treatment programs. Third trimester interviews were conducted to determine quantity, frequency, and variability of drug and alcohol use during both the pre-pregnancy and pregnancy periods. Reports of use during pregnancy were verified using results of urinalysis screens and infant meconium. Daily maternal methadone dose, as well as entry into methadone treatment, number of missed doses, and magnitude of dose increase during pregnancy were extracted from medical records.
Developmental Screening. At 9 months postnatal age, infants were assessed using the Bayley Scales of Infant and Toddler Development – Third Edition (BSID-III) as a broad screen for developmental delay. The BSID-III assesses cognitive, motor, language, and social-emotional development, as well as adaptive behavior. Scores are normed in relation to a typically-developing comparison group.
Event-Related Potentials: Results of the BSID-III are compared to a 7-month event-related potential. Infants are tested at 7-months postnatal age using the auditory oddball paradigm. Recordings are taken every two seconds from frontocentral electrode sites (Fz, Cz, Pz) using the International system. The auditory oddball paradigm was presented using a frequently-occurring (80% of trials) 1kHz tone and a rarely occurring (20% of trials) 2kHz tone presented randomly.
Results
Table 1. Bayley Motor: Prenatal Opiate Dose Change
36% of opiate-exposed infants exhibited clinically significant (>1.5 SD) motor delays.
Motor Composite Score
Figure 1. Bayley Cognitive and Language: Prenatal Alcohol *
Standard Score
Predictor B
SEB β t
Total Dose Change During Pregnancy
-.11
.05
-.49
-2.22
Maternal Age
-2.45
.82
-.65
-2.97
Figure 1. History of Maternal Problem Drinking Affects Cognitive and Language Development. Infants born to mothers with a history of problem drinking, determined by a Michigan Alcohol Screening Test (MAST) score >4, the clinical cutoff for problem drinking, revealed significant reductions in BSID-III Cognitive [F(1,26)=6.645, p<.02] and Language [F(1,26)=3.698, p<.05] Composite scores.
These delays were specific to truncal tone development:
- elevates trunk while prone: elbows and forearms (p<.05)
- moves from sitting to hands and knees
(p<0.01)
- sits with support briefly (p<0.05)
Table 1. Predictors of Motor Development. Total maternal dose change during pregnancy and maternal age explained 39.9% of the variance (R2 = .39; F=1.979, p<.05) in the BSID-III Motor Development Composite Score.
Summary
Methadone-exposed infants are at risk for neurodevelopmental delay due to exposure to opiates in utero, as well as exposure to alcohol and other sociodemographic risk factors.
Motor delays occur at a rate higher than predicted by normative base rates, and are driven largely by delays in truncal tone development, including sitting independently and crawling.
History of maternal alcohol use coupled with methadone exposure results in significant delays in cognitive and language composite scores.
Cognitive scores are predicted by information processing speed at 7 months of age, such that infants with slower information processing speeds have lower cognitive scores at 9 months postnatal age.
Table 2. 7-month ERP Predicts 9-month BSID-III
Predictor B
SEB β t
Amplitude of frequent stimulus during early trial blocks
-.57
.19
-.52
-2.95
Latency (ms) P2
Table 2. 7-month ERP Predicts 9-month BSID-III: The amplitude to the frequent stimulus during early trial blocks (lower amplitudes on average are suggestive of faster information processing speed) explained 27.5% of the variance (R2 = .27; F = 8.68, p < .01) in the BSID-III Cognitive Development Composite Score.
References
Lester, B. M., Tronick, E. Z., LaGasse, L., Seifer, R., Bauer, C. R., Shankaran, S., et al. (2002). The maternal lifestyle study: effects of substance exposure during pregnancy on neurodevelopmental outcome in 1-month-old infants. Pediatrics, 110(6),
Messinger, D. S., Bauer, C. R., Das, A., Seifer, R., Lester, B. M., Lagasse, L. L., et al. (2004). The maternal lifestyle study: cognitive, motor, and behavioral outcomes of cocaine-exposed and opiate-exposed infants through three years of age. Pediatrics, 113(6),
Sponsored By: NIH to M.J. Hayes