The aim of this study is to characterize the interest of concentrations in meconium of drugs used for treatment of pregnant opioid-dependent woman as a prognostic factor of time, severity and duration of neonatal abstinence syndrome (NAS). 43 women treated with buprenorphine, 49 with methadone, and their newborns, were included. NAS is assessed by Lipsitz scale. Buprenorphine, norbuprenorphine, methadone, EDDP and morphine are quantified in meconium (one collected immediately after birth, another for 24 to 48 h) by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, developed and validated for this study.

Inclusion Criteria:

• Aged over 18 years
• pregnant women
• Having agreed to participate in the study after information
• Under opioid replacement therapy during pregnancy, in combination or not with other psychotropic drugs or legal or illegal substances.
• Delivery after more than 34 weeks of amenorrhea

Exclusion Criteria:

• Pregnant women not receiving substitution treatment (methadone or buprenorphine).
• Patient under substitution treatment delivering before 34 weeks of amenorrhea
• Patient aged under 18 yrs old
• Patient unable to understand the study (mental deficiency, impairment of consciousness, not French) or not accepting to answer the questionnaires.
• Severe malformation syndrome or chromosomal abnormality in newborn discovered during pregnancy.
• mother's death or newborn's death

Newborns and mothers under opioid replacement therapy during pregnancy