Introduction Studies conducted all over the world show that the rates of pregnancy in adolescence are increasing, especially in the early adolescence (10–14 years of age). Although the majority of pregnancies in this period are not desired some studies suggest that a number of them are wanted. Aims: (1) Assess the prevalence of wanted pregnancy and possible associations with socioeconomic, demographic factors and social support network in a population of pregnant adolescents (2) Verify if age should be an effect modifier in these associations.

Methods Cross sectional study conducted with pregnant adolescents regularly attending two public maternity units. A sample of 232 pregnant adolescents aged 13–20 years (mean 17.3 years) completed a self-reported questionnaire.

Results Prevalence of intended pregnancy was 46.2%. Final adjusted model showed that being married (PR 1.80, 95% CI 1.27 to 2.56) and not having friends (PR 1.48, 95% CI 1.15 to 1.90) showed association with the desire to be pregnant. Girls studying in the elementary grade and aged 12–16 years desired to be pregnant less (PR 0.57, 95% CI 0.38 to 0.88).

Conclusion Pregnancy in adolescence may not always be unwanted. Some factors, such as being married and not having any friends may have influence in these cases. Professionals dealing with adolescents should be aware of these issues in order to identify high risk situations that could be managed.