Objective: To evaluate the prevalence of cocaine and marijuana use during the third trimester of pregnancy in a population of 1000 teenage women of a public hospital in São Paulo, Brazil using hair analysis in order to avoid underestimation of data that could happen by the use of self-report questionnaires and describe socio-demographic, psychosocial and behavioral characteristics of the drug users.
Results: Hair analysis has detected use of cocaine and/or marijuana in the third trimester of pregnancy in 6% of the patients: 4.0% used marijuana, 1.7% used cocaine and 3% used both drugs. They were about 17 years old, from low-income, poorly educated, unemployed, financially dependent and they had not planned the pregnancy. 10% of miscarriages have occurred in this population.
Conclusion: This study shows the psychosocial impairment associated to teenage pregnancy and use of cocaine and marijuana during gestation by this low-income population with reliable data of prevalence obtained through hair analysis.