Association between elevated third trimester maternal haemoglobin and neonatal gestational age adjusted birth weight
Date of Award
Master of Medicine (MMed)
Obstetrics and Gynaecology (East Africa)
Background: Women tend to have lower haemoglobin compared to men due to menstrual blood losses. This is often compounded by nutritional deficiencies. There is a further drop in haemoglobin during pregnancy due to red cell dilution. Pregnancy itself places a huge demand on maternal iron stores. High haemoglobin may reflect haemoconcentration due to a failure of the normal physiological expansion in plasma volume. Iron excess has also been associated with free-radical damage. In current practice, high maternal haemoglobin in pregnancy is often not given as much attention as anaemia. This study examines the association between high maternal haemoglobin in the third trimester and neonatal birth weights as well as other maternal and neonatal outcomes.
Objectives: To determine the potential association between elevated third trimester maternal haemoglobin and neonatal gestational age adjusted birth weights at term.
Methods: In this retrospective cohort study, women delivering at the Aga Khan University Hospital’s maternity unit who had either normal or high haemoglobin levels in their third trimester of pregnancy were recruited at delivery. Information about the pregnancy outcome was then recorded for analysis. The primary outcome measure was neonatal gestational age adjusted birth weights.
Results: No difference was found in the proportions of small for gestational age newborns between mothers with elevated haemoglobin and those with normal haemoglobin in the third trimester [9.9% 95% CI (7.4 to 13.1) and 9.7% 95% CI (6.5 to 13.8) respectively]. Similarly no difference was detected in the secondary outcomes of maternal hypertension, mode of delivery as well as other neonatal outcomes, though the study was not powered to detect differences in these outcomes.
Conclusion: There is evidence of no association between elevated maternal haemoglobin in the third trimester and small for gestational age newborns in this study population.
Achila, B. O. (2013). Association between elevated third trimester maternal haemoglobin and neonatal gestational age adjusted birth weight (Unpublished master's dissertation). Aga Khan University, East Africa.