Methamphetamine use during pregnancy and weak evidence of adverse neonatal outcomes

Aims: We aimed to compare neonatal outcomes in new-borns exposed to methamphetamine (MA) with new-borns of mothers from the general population, mothers who discontinued MA use during pregnancy, and opioid dependent mothers.

Design: Nationwide register-based cohort study using personalized IDs assigned to all citizens for data linkage.

Setting: The Czech Republic (2000–2014).

Participants: A total of 258 women diagnosed with ICD-10 F15 during pregnancy and their children. The comparison group consisted of women (n= 1,511,310) with no ICD-10 F10 to F19 diagnosis (general population), women (n=199) diagnosed with ICD-10 code F11 (all sub-codes), and women who had a history of hospitalization with ICD-10 F15 but no use during pregnancy and children of women from there groups.

Measurements: On data from nationwide registries, we performed multivariate linear regression and binary logistic regression to explore the associations between MA and neonatal outcomes. Regression coefficient (b) and Odds ratio (OR) were estimated.

Findings: Women using MA during pregnancy had worse socio-economic characteristics as compared to the general population of pregnant women and mother using opioids during pregnancy. Relative to children of the non-using mothers, MA reduced birth weight (adjusted b = 61.83 grams, 95% confidence interval (CI) = -122.2—0.3) and birth length (adj b = -0.3 cm, 95% CI = -0.6—0.0). Only birth weight and length were significantly reduced in the opioid exposed, while no statistically significant differences were found between the MA exposed children and those of mothers who discontinued MA use during pregnancy.

Conclusions: New-borns of women using MA during pregnancy had only slightly worse anthropometric data as new-borns of women from the general population, opioid using women, or women who discontinued use during pregnancy. Worsened neonatal outcomes in new-borns exposed to MA during pregnancy may be attributed to the drug-related lifestyle, health care and social risk factors rather than to the effect of MA on the foetus.