To estimate the prevalence of suicidal ideation during gestation and risk factors for depression in postpartum.

712 pregnant women answered the PRIME MD, and reported sociodemographic data, obstetric history and history of violence; 427 women answered the PRIME MD at 4-5^th month postpartum. Poisson regression was used to estimate the association between suicidal ideation and sociodemographic, obstetric and violence variables, and to estimate the association between risk factors and depressive symptoms in postpartum.

The prevalence of suicidal ideation during pregnancy was 10.3% (n=73). The prevalence of depression was 36.2% (n=258). Suicidal ideation was associated with: 0 to 4 years of schooling (PR=2.88, CI 95% 1.40-5.91), and 5 to 8 years of schooling (PR=2.63, CI 95% 1.45-4.77), being victim of violence in the current gestation (PR=4.35, CI 95% 2.81-6.74), and anxiety symptoms (PR= 5.49, CI 95% 3.58-8.40).

The prevalence of depression in the postpartum was 28.3% (n=121); 45 were incident cases (37%). The following variables were significantly associated with depression in postpartum: <19 years of age (RR=1.82, CI 95% 1.03-3.22), 20-29 years of age (RR=2.19, CI 95% 1.30-3.66), lower income (RR= 1.49, CI 95% 1.00-2.23), depressive symptoms during gestation (RR=2.9, CI 95% 2.13- 3.97), anxiety symptoms during gestation (RR= 2.96, CI 95% 2.26-3.88), and being victim of violence during gestation (RR=2.04, CI95% 1.50-2.78).

Gestation is not protective of suicidal ideation and common mental disorders. Treating common mental disorders during pregnancy is essential to prevent depression in post partum and to promote maternal's and infant's health.