OBJECTIVES : Anemia is common amongst women in developing countries. Although a relationship has been established between gestational anemia and negative perinatal outcomes, it remains a controversial debate as opposite associations have been found. This study assessed the relationship between gestational anemia in the third trimester and low birth weight (LBW) in the ESE Clinica Maternidad Rafael Calvo, a reference maternity unit in the department of Bolivar, Colombia.

METHODS : A total of 773 women were enrolled during the last trimester of their pregnancy, between December 2018 and December 2019. Obstetric and perinatal information was assessed, as well as personal and socio-economical background. Blood samples were taken prior to delivery and analysis was based on maternal blood count coupled with infant anthropometric data.

RESULTS : Fifty-five (7.1%) of the 773 infants were born underweight (<2.500 g)in the entire cohort and in 3% of full-term newborns (22 out of 710). Newborns from anemic mothers had higher weight at birth than those from non-anemic mothers (p=0,039). Low birth weight was inversely associated to gestational anemia in the third trimester of pregnancy (<11g/dL; OR: 0.48; CI95%:0.26-0.80; p=0.018). A relationship was found between anemia and poor prenatal follow-up (<4 appointments; OR:0,26; IC95%:0,11-0,63;p=0,003) and LBW was associated to low ferritin levels (<12 ng/mL; OR: 0.41; IC95%:0,23-0,73; p=0,02). Anemia or maternal low ferritin level were not associated with premature birth.

CONCLUSIONS : A negative association between gestational anemia in the third trimester and LBW is highlighted. Strengthening of prenatal care policies can contribute to the prevention of LBW.