TABLE 1.

CDC trimester-specific mean hemoglobin concentrations and anemia cutoffs¹

	Trimester
	1	2			3
Weeks of gestation	12	16	20	24	28	32	36	40
Mean hemoglobin, g/dL	12.2	11.8	11.6	11.6	11.8	12.1	12.5	12.9
Anemia, g/dL	<11.0	<10.5			<11.0

¹Data were based on mean hemoglobin concentrations obtained from 4 longitudinal studies carried out in pregnant European women (32–35). Anemia is defined as a trimester-specific hemoglobin concentration below the fifth percentile. Modified from reference 31.