To analyse the modalities and consequences of multiple drug use during pregnancy.
170 neonates whose mothers declared using at least two psychoactive substances, in a French hospital, between 1999 and 2008 were studied. Data was obtained from obstetrical, neonatal and addiction file records.
The identified mothers used on average three products at delivery, mostly tobacco, opiate substitution treatment, cannabis, alcohol and benzodiazepines. The birth cohort effect was very marked. The women using more than four substances experienced significantly more pregnancy terminations in their lives. Their newborns showed significant differences in terms of preterm births (31.3% < 37 weeks), birth weights, sizes and neonatal abstinence syndromes (37.5% had a Lipsitz score >9). They were twice as likely to be taken into foster care. Long hospitalisations were three times more frequent for them (32.8% duration >30 days).
Multiple drug use in pregnancy is a risk factor resulting in poor outcome whatever the combination of substances.