Maternal and neonatal outcomes associated with haemoglobin concentration in pregnancy: a Burden of Proof study.

Risk estimates accounting for uncertainty and quantitative star ratings were generated to assess evidence strength.

Our analysis revealed that even small deviations above or below hemoglobin levels with the lowest predicted risk - particularly on the low end (anemia)-were associated with non-linear increased risks of all-cause maternal and neonatal mortality, postpartum hemorrhage, maternal sepsis, preterm birth, low birthweight and large-for-gestational-age.