Les chiffres de prévalence de la consommation de substances durant la grossesse sont inconnus en France et probablement sous-évalués dans le reste du monde car les études ont eu le plus souvent recours à des questionnaires et non à des dosages. Les conséquences potentielles de cette consommation sont obstétricales (celle-ci augmente le risque d’avortement spontané, de placenta praevia, de menace d’accouchement prématuré…), néonatales (augmentation de la prématurité et risque de syndrome de sevrage plus ou moins important selon la substance, la dose consommée et l’ancienneté de la consommation), et surtout à plus long terme chez l’enfant. Les conséquences diffèrent selon les produits mais globalement, les enfants exposés présenteraient davantage de troubles cognitifs (troubles de l’attention, de la mémoire et des fonctions exécutives), de troubles du comportement (impulsivité, hyperactivité avec déficit de l’attention), de retard de croissance, de symptômes psychiatriques (anxiété, symptômes dépressifs…). Les relations entre l’exposition in utero au cannabis et l’apparition chez le jeune adulte d’une schizophrénie sont controversées. De même, l’existence d’une relation entre une augmentation du risque de consommation de substances et l’exposition au tabac, au cannabis ou à la cocaïne durant la grossesse n’est pas clairement établie. Les divergences entre les résultats des différentes études proviennent de biais méthodologiques importants, notamment le rôle potentiel des facteurs environnementaux et génétiques, de différences entre les populations étudiées et les échelles d’évaluation utilisées. Des études portant sur des cohortes plus importantes et sur des périodes plus longues apparaissent nécessaires.

Substance use has increased worldwide. Based on these data, we may think that substance use has also increased during pregnancy, but epidemiological data are scarce in this population. The potential consequences of tobacco, cocaine or cannabis use during pregnancy are a major public health concern. The combined use of different substances during pregnancy may have serious consequences on the pregnancy and on child development.

In this paper, we will describe the potential consequences for the newborn, child and adolescent after being exposed to tobacco, cannabis and cocaine in utero. For this purpose, we will review all retrospective and prospective studies (in English and French) referenced in PubMed reporting on the somatic or psychiatric consequences of alcohol, tobacco and drug consumption by pregnant women on newborn and children. Consumption during pregnancy was assessed in these studies using simple questionnaires, biomarkers analysis or both.

Generally speaking, these pregnancies are at high risk for both the mother and the foetus: for example, an increased risk of miscarriage or of reduced length of gestation, an increased risk of uterine apoplexy and placenta praevia, more premature births and/or hypotrophy were reported. The occurrence of a newborn's withdrawal syndrome may be misdiagnosed. Many consequences on child development may be observed such as growth disorders, learning or motor disorders, language disorders, cognitive disorders (attention, memory, executive functions), attention deficit disorders with impulsivity or with hyperactivity (ADHD), and memory disorders. The prevalence of depressive or anxiety disorders may also be increased in these children. The risk of addictive disorders or schizophrenia in children exposed in utero to illicit drugs or tobacco is still unknown. The combined use of different substances increases, consequently it is difficult to disentangle the consequences on child development of each of the drugs used during pregnancy owing to potential interactions between these drugs. The consequences on child development will also depend on the dose and on the time of drug use during pregnancy.

The National Institute of Drug Abuse reported that 75% of the infants exposed in utero to one or more substances will present medical problems during childhood, as compared to only 27% of the non-exposed infants. However, the medical consequences are still a matter of controversies. Methodological biases, such as the use of different rating scales among studies, and the heterogeneity of the populations included are main limitations. Further studies are needed using larger cohorts and longer follow-up periods.