Association of hemoglobin values at booking with adverse maternal outcomes among Peruvian populations living at different altitudes

ObjectiveTo determine hemoglobin values associated with adverse maternal outcomes among Peruvian populations at different altitudes.MethodsA retrospective cohort study was conducted using data from the Perinatal Information System. Adverse maternal outcomes were assessed.ResultsRisk of pre-eclampsia increased at maternal hemoglobin levels above 14.5 g/dL (OR 1.27; 95% CI, 1.18–1.36) or below 7.0 g/dL (OR 1.52; CI 95%, 1.08–2.14). Altitude above 2000 m reduced risk (OR 0.65; 95% CI 0.62–0.68). Risk of postpartum hemorrhage (PPH) increased with moderate/severe anemia (OR 6.15; 95% CI, 3.86–9.78) and at moderate altitudes (OR 1.26; 95% CI, 1.12–1.43). Mild anemia at any altitude was associated with reduced risk of pre-eclampsia (OR 0.85, 95% CI, 0.81–0.89) and PPH (OR 1.01; 95% CI, 0.88–1.15). Risk of premature rupture of membranes was reduced at high hemoglobin values. Maternal mortality increased at hemoglobin levels below 9.0 g/dL (OR 5.68; 95% CI, 2.97–10.80) and above 14.5 g/dL (OR 2.18; 95% CI, 1.22–3.91). Maternal mortality increased at moderate altitudes (OR 29.2; 95% CI, 2.62–324.60) and high altitudes (OR 66.4; 95% CI, 6.65–780.30) when hemoglobin levels were below 9.0 g/dL.ConclusionElevated altitude and hemoglobin levels influence maternal outcomes.