Infants of drug addicted mothers who terminated drug use prior to the second trimester manifested fewer abnormalities of relative power spectrums of quantitative electroencephalographic (Qeeg) recordings (QSI 9000) of all brain regions compared to infants whose mothers continued to use drugs.

Twenty-four infants (BW 2806 +/- 758g; GA 37.6 +/- 3.5wks) exposed in utero to heroin and/or cocaine for a minimum of two trimesters and 5 infants exposed to drugs for only the first trimester (BW 2970 +/- 440g; GA 38.4 +/- 1.4wks) were evaluated at term. Nineteen channels of EEG were recorded according to the International 10-20 system and three to five minutes of analog EEG signal were filtered between 0.5 Hz and 30 Hz, the data digitized at a 102.4 Hz, sampling rate and stored on optical disk. The results were then compared to a normative neonatal database.

Infants of mothers who abstained before the 2nd trimester presented with no abnormal Z-scores in relative power in either the Delta, Alpha or Theta bands of the (F)rontal, (C)entral, (T)emporal, (P)ariental or (V)ertex regions of the brain. In contrast, of the 24 infants exposed for longer duration, abnormal Z-scores were noted in 25% in F, 29% in C, 46% in T, 38% in P and 38% in V areas.

We conclude that there is a duration dependent relationship between prenatal drug exposure and neonatal brain activity.