The impact of maternal experience of violence and common mental disorders on neonatal outcomes: a survey of adolescent mothers in Sao Paulo, Brazil

Background: Both violence and depression during pregnancy have been linked to adverse neonatal outcomes, particularly low birth weight. The aim of this study was to investigate the independent and interactive effects of these maternal exposures upon neonatal outcomes among pregnant adolescents in a disadvantaged population from Sao Paulo, Brazil. Methods: 930 consecutive pregnant teenagers, admitted for delivery were recruited. Violence was assessed using the Californian Perinatal Assessment. Mental illness was measured using the Composite International Diagnostic Interview ( CIDI). Apgar scores of newborns were estimated and their weight measured. Results: 21.9% of mothers reported lifetime violence ( 2% during pregnancy) and 24.3% had a common mental disorder in the past 12 months. The exposures were correlated and each was associated with low education. Lifetime violence was strongly associated with Common Mental Disorders. Violence during pregnancy ( PR = 2.59( 1.05 - 6.40) and threat of physical violence ( PR = 1.86( 1.03 - 3.35) and any common mental disorders ( PR = 2.09 ( 1.21 - 3.63) ( as well as depression, anxiety and PTSD separately) were independently associated with low birth weight. Conclusion: Efforts to improve neonatal outcomes in low income countries may be neglecting two important independent, but correlated risk factors: maternal experience of violence and common mental disorder.