gynecology and obstetrics
Anemia in Pregnancy
Introduction
Normally during pregnancy, erythroid hyperplasia of the marrow occurs, and red blood cell (RBC) mass increases. However, a disproportionate increase in plasma volume results in hemodilution (hydremia of pregnancy): hematocrit (Hct) decreases from between 38% and 45% in healthy women who are not pregnant to about 34% during late single pregnancy and to 30% during late multifetal pregnancy. The following hemoglobin (Hb) and Hct levels are classified as anemic: 1st trimester: Hb < 11 g/dL; Hct < 33% 2nd trimester: Hb < 10.5 g/dL; Hct < 32% 3rd trimester: Hb < 11 g/dL; Hct < 33% If Hb is<11.5 g/dL at the onset of pregnancy, women may be treated prophylactically because subsequent hemodilution usually reduces Hb to<10 g/dL. Despite hemodilution, oxygen-carrying capacity remains normal throughout pregnancy. Hct normally increases immediately after birth. Red Blood Cell Production occurs in up to one third of women during the 3rd trimester. The most common causes are Iron Deficiency None Folate Deficiency None Obstetricians, in consultation with a perinatologist, should evaluate anemia in pregnant Jehovah's Witness patients (who are likely to refuse blood transfusions) as soon as possible. 