Red blood cell parameters in antenatal nonsickling hemoglobinopathy screening

Figures & data

Table 1 The hematological data of the four groups – group 1: nonsickling hemoglobinopathies (24); group 2: IDA (89); group 3: anemia of other etiology (62); group 4: normal (654)

	Group 1		Group 2		Group 3		Group 4
	Mean (SD)	Range	Mean (SD)	Range	Mean (SD)	Range	Mean (SD)	Range
Hb (g/L)	112 (14.2)	75–147	101 (7.0)	74–109	104 (6.3)	83–109	125 (8.7)	110–158
RBC (×10^6/μL)	4.8 (0.5)	3.7–5.9	3.6 (0.3)	3.0–4.5	3.5 (0.3)	2.7–4.6	4.1 (0.4)	2.8–7.1
HCT (%)	33.9 (4.1)	24–43	29.8 (2.0)	23–34	29.9 (1.7)	25–32	35.9 (2.6)	30–49
MCV (fL)	71 (6.0)	59–82	83 (7.4)	66–98	87 (5.9)	69–109	87 (4.5)	69–105
MCH (pg)	24 (2.3)	20–28	28 (3.0)	21–35	30 (2.5)	22–38	31 (1.9)	21–37
	Median	Range	Median	Range	Median	Range	Median	Range
MRC (%)	18.6	2.5–59	1.8	0.1–35	0.9	0.1–27	0.6	0–10
HRC (%)	7.6	0.3–15	2.8	0.1–36	0.6	0.1–16	0.2	0–11
Ferritin (μg/L)	50	5–533	8	2–20	46	21–192

Note: Parameter was not determined in this group.

Abbreviations: Hb, hemoglobin; HCT, hematocrit; IDA, iron deficiency anemia; MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume; MRC, microcytosis; HRC, hypochromic erythrocytes; RBC, red blood cell; SD, standard deviation.

Figure 1 Receiver operating characteristic curves of the three parameters for nonsickling hemoglobinopathy screening among nonanemic women.

Abbreviations: MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume; MRC, microcytosis.

Table 2 Specificity, sensitivity, PPV, NPV, and Youden’s index of different cut-off levels for MCV in (a) nonanemic pregnant women and (b) women with IDA

MCV, fL	Sensitivity	Specificity	PPV	NPV	Youden’s index, %
(a)
≤75	66.7	99.2	76.2	98.8	65.9
≤76	75.0	99.1	78.3	99.1	74.1
≤77	75.0	98.6	66.7	99.1	73.6
≤78	87.5	98.0	61.8	99.5	85.5
≤79	91.7	97.1	53.7	99.7	88.8
≤80	95.8	95.4	43.4	99.8	91.2
≤81	95.8	93.9	36.5	99.8	89.7
(b)
≤74	66.7	86.5	57.1	90.6	76.6
≤75	66.7	82.0	50.0	90.1	74.4
≤76	75.0	78.6	48.7	92.1	76.8
≤77	75.0	75.3	45.0	91.8	75.2

Note: Results expressed in %.

Abbreviations: IDA, iron deficiency anemia; MCV, mean corpuscular volume; NPV, negative predictive value; PPV, positive predictive value.

Table 3 Specificity, sensitivity, PPV, NPV, and Youden’s index of different cut-off levels for MCH in (a) nonanemic pregnant women and (b) women with IDA

MCH, pg	Sensitivity	Specificity	PPV	NPV	Youden’s index, %
(a)
≤25	79.2	99.2	79.2	99.2	78.4
≤26	79.1	97.9	57.6	99.2	77.0
≤27	87.5	96.3	46.7	99.5	83.8
≤27.5	95.8	94.9	41.1	99.8	90.7
≤28	95.8	91.3	28.8	99.8	87.1
(b)
≤23	54.2	95.5	76.5	88.5	74.9
≤24	75.0	91.0	69.2	93.1	83.0
≤25	79.2	83.2	55.9	93.7	81.2
≤26	79.2	71.9	43.2	92.8	75.6

Note: Results expressed in %.

Abbreviations: IDA, iron deficiency anemia; MCH, mean corpuscular hemoglobin; NPV, negative predictive value; PPV, positive predictive value.

Table 4 Specificity, sensitivity, PPV, NPV, and Youden’s index of different cut-off levels for MRC in (a) nonanemic pregnant women and (b) women with IDA

MRC, %	Sensitivity	Specificity	PPV	NPV	Youden’s index, %
(a)
≥3	95.8	94.4	40.4	99.8	90.2
≥5	75.0	98.1	60.0	99.1	73.1
≥10	70.8	99.5	85.0	99.0	70.3
≥15	58.3	99.8	93.3	98.5	58.1
(b)
≥3	95.8	58.4	38.3	98.1	77.1
≥5	75.0	73.0	42.9	91.6	74.0
≥10	70.8	84.3	54.9	91.5	77.6
≥15	58.3	89.9	60.9	88.9	74.1

Note: Results expressed in %.

Abbreviations: IDA, iron deficiency anemia; MRC, microcytosis; NPV, negative predictive value; PPV, positive predictive value.

Figure 2 The algorithm of targeted antenatal nonsickling hemoglobinopathy screening.

Abbreviations: HPLC, high-performance liquid chromatography; MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume.