Background: Postpartum haemorrhage and blood transfusion are increasing. Antenatal detection and correction of anaemia is an effective strategy to reduce the significance of blood loss at birth.
Aim: To use routinely collected data for obstetric patients to ascertain whether levels of haemoglobin (Hb) at ≤20 weeks of gestation are associated with blood transfusion and other adverse pregnancy outcomes at birth.
Methods: Clinical data cohort of all singleton births 20 to 42 weeks of gestation at Royal North Shore and Westmead hospitals between 2011 and 2015. The lowest Hb result in the first 20 weeks of pregnancy was ascertained from ObstetriX maternity data or hospital pathology results. The outcomes were blood transfusion in the birth admission and adverse maternal and neonatal outcomes.
Results: There were n=32,479 singletons births with a valid Hb result and without a history of blood disorder. Of these, n=29 (0.1%) had a Hb <80g/L, n=1557 (4.8%) had a Hb 80-110g/L, and n=30,893 (95.1%) had a Hb >110g/L at ≤20 weeks. Women with a Hb ≤110g/L were more likely to have a blood transfusion in the birth admission and more likely to have severe morbidity than women with a Hb of >110 g/L, and their babies were more likely to be born preterm, be small for gestational age, and be transferred to higher care after birth.
Conclusion: Initial unadjusted analyses suggest that lower haemoglobin levels in the first half of pregnancy are associated with higher rates of blood transfusion and poorer outcomes for mother and baby.