Maternal Hemoglobin Concentration During Pregnancy and Risk of Stillbirth

Abstract
The relationship between maternal hematological parameters and pregnancy outcome has been a source of continuing controversy. In developed countries, not only maternal anemia1-3 but also high hemoglobin concentration during pregnancy4-9 has been reported to increase the risks of unfavorable outcomes such as small-for-gestational-age (SGA) birth, preterm birth, and perinatal death. The associations between hemoglobin concentration in early pregnancy, changes in hemoglobin concentration during pregnancy, and risk of stillbirth are not known.10