Developmental outcomes following prenatal exposure to methamphetamine: A Western Australian perspective

To describe neurodevelopmental outcomes among a cohort of Western Australian infants exposed to maternal methamphetamine use during pregnancy and to determine whether the Ages and Stages Questionnaire is a reliable screening tool for this population.

Methamphetamine-using women were approached for participation when referred to the state-wide perinatal specialist drug and alcohol service for pregnancy care. Drug use during pregnancy was self-reported in each trimester using a standardised questionnaire. Ages and Stages Questionnaires were completed by infant care givers at 4 and 12 months, and development was formally assessed at 12 months using the Griffiths Mental Development Scales. Griffiths results for term-born infants in our cohort were compared to a Western Australian historical cohort of 443 healthy 1-2-year-olds.

A total of 112 methamphetamine-using pregnant women participated in the study, who gave birth to 110 live-born infants. Ages and Stages Questionnaires were completed for 89 (81%) and 78 (71%) of the infants at 4 and 12 months, respectively. The Ages and Stages assessment identified 30 infants (33.7%) as having a potential developmental delay at 4 months and 29 infants (38.7%) as having a potential developmental delay at 12 months. Griffiths assessments were performed on 64 (58%) of the infants, with a mean general quotient of 92.7. This was significantly lower in term-born babies compared to the historical cohort (who had a median general quotient of 113.0). There was a weak correlation between 12-month Ages and Stages scores and Griffiths general quotients (r = 0.322) and no correlation between 4-month Ages and Stages Questionnaire scores and later Griffiths results.

Infants born to women reporting methamphetamine use during pregnancy are at increased risk of developmental delay and may warrant enhanced developmental follow-up. However, they are a challenging group to follow due to complex psychosocial factors. Ages and Stages Questionnaires at 4 and 12 months were not helpful in screening for infants who had a developmental delay at 12 months.