Maternal characteristics and pregnancy outcomes among illicit drug-using women in an urban setting

To identify characteristics and pregnancy outcomes among pregnant illicit drug users living in an urban area, and to describe trends in drug use over an 8-year period.

Data on pregnant women living in the Bangkok Metropolitan Region who delivered at our institution during 2008-2015 were studied. Women with drug use (n = 197) and women without drug use (n = 787) were compared in terms of maternal characteristics and pregnancy outcomes.

The pregnant drug user rate markedly rose from 0.46% in 2008 to 1.28% in 2015. All pregnant drug users consumed amphetamine-type stimulants (ATS). The most important factor related to drug use was smoking (adjusted odds ratio [aOR] 41.03, 95% confidence interval [CI] 18.90-89.04). Other significant characteristics were teenage pregnancy (aOR 1.78, 95% CI 1.01-3.18), low level of education (aOR 4.97, 95% CI 1.18-20.90 for secondary school and aOR 5.61, 95% CI 1.28-24.49 for primary school or lower), and inadequate number of antenatal visits (aOR 2.20, 95% CI 1.16-4.17 for 1-3 visits and aOR 14.05, 95% CI 7.54-26.16 for no visit). Women of non-Thai ethnicity were less likely to use drugs (aOR 0.15, 95% CI 0.04-0.54). Pregnant drug users had a significantly higher risk of anemia (aOR 1.73, 95% CI 1.05-2.85), preterm delivery (aOR 2.35, 95% CI 1.29-4.29), low birth weight (aOR 2.26, 95% CI 1.23-4.17) and small for gestational age infants (aOR 3.19, 95% CI 1.39-7.33), but lower risk of cesarean section (aOR 0.43, 95% CI 0.21-0.86) than non-drug users.

Compared to urban pregnant women without drug use, women who consumed drugs were younger, had lower level of education, poorer self-care and poorer pregnancy outcomes. ATS was the single most commonly used drug.