This study tested the hypothesis that the birthweight paradox would not be observed when assessing the effect of maternal education on neonatal mortality in the presence of socioeconomic inequality in access to health care.Methods
Non-concurrent cohort study. Passive follow-up of live-born infants using probabilistic record linkage of birth and death records for Rio de Janeiro (2004-2010; n = 1 445 367). Maternal age, birthweight and neonatal death were evaluated according to maternal educational level strata (<4, 4-11 and ≥12 years of study). We estimated the association between maternal educational level and neonatal mortality using logistical regression models adjusted for maternal age and birthweight (<2500 g and ≥2500 g).Results
Neonatal mortality was 1.8 times higher in low educational level group compared with high educational level. We did not find birthweight-specific mortality curves crossing over in the stratum under 2500 g (birthweight paradox). The odds of a low birthweight child being born in facilities without neonatal intensive care units was about 70% higher in the group of low education when compared with mothers with high education.Conclusions
The absence of crossing birthweight-specific mortality curves may be a reason for concern about the severity of the disadvantages faced by low maternal education women.