Table 2 Factors associated with ZPP (μmol/mol haem) measured in whole blood ^a

Gravidity

0.68

0.04

Primigravida

Secundigravida

–2.3%

(–15.6% to 13.1%)

0.5%

(–9.6% to 11.8%)

Multigravida

2.7%

(–8.9% to 15.7%)

9.4%

(0.1% to 19.6%)

Gestational age

0.87

0.008

13–14 weeks

15–16 weeks

5.4%

(–11.3% to 25.3%)

6.7%

(–5.6% to 20.7%)

16–18 weeks

6.1%

(–10.4% to 25.7%)

–4.0%

(–14.9% to 8.3%)

19–21 weeks

2.0%

(–14.3% to 21.3%)

–7.3%

(–18.2% to 5.1%)

22–25 weeks

–1.0%

(–19.0% to 20.9%)

–11.0%

(–23.0% to –2.8%)

Anaemia

64%

(51.2% to 77.8%)

<0.001

33.5%

(23.9% to 43.9%)

<0.001

Iron deficiency^d

26.3%

(15.8% to 37.8%)

<0.001

16.6%

(9.1% to 24.6%)

<0.001

Plasma sTfR concentration, mg/L

31.9%

(28.1% to 35.9%)

<0.001

24.5%

(20.6% to 28.5%)

<0.001

Plasma transferrin concentration, g/L

30.9%

(21.4% to 41.2%)

<0.001

–

Plasma folate concentration, 10 μg/L

6.1%

(–7.2% to 21.4%)

0.39

12.8%

(2.9% to 22.7%)

0.01

Plasma vitamin B₁₂ concentration, 100 pmol/L

–1.8%

(–3.4% to –0.2%)

0.03

–

Plasma total bilirubin concentration, μmol/L

0.7%

(–0.4% to 1.8%)

0.20

–

Plasma LDH concentration, 10 IU/L

1.5%

(0.6% to 2.5%)

0.001

–

α ⁺-thalassaemia genotype

0.67

Normal

–

Heterozygote

–3.8%

(–16.1% to 10.2%)

–

Homozygote

–10.0%

(–30.2% to 16.1%)

–

Plasmodium infection

Any Plasmodium spp., by any dipstick or PCR

8.0%

(–1.6% to 18.4%)

0.10

–

Current or recent P. falciparum infection^e

5.1%

(–6.2% to 17.8%)

0.39

–

P. falciparum, by dipstick^e or PCR

8.1%

(–1.4% to 18.6%)

0.10

–

P. falciparum, by PCR

9.9%

(0.1% to 20.7%)

0.05

–

HIV infection

5.2%

(–14.9% to 6.2%)

0.37

–

Plasma CRP concentration, mg/L

0.2%

(–0.1% to 0.5%)

0.27

–

Plasma AGP concentration, g/L

21.5%

(3.2% to 43.0%)

0.02

–

Inflammation^f

Plasma CRP concentration ≥10 mg/L

5.0%

(–5.1% to 16.1%)

0.34

–

Plasma AGP concentration ≥1.0 g/L

14.0%

(–1.5% to 27.9%)

0.03

–

Plasma CRP concentration ≥10 mg/L, or AGP ≥1.0 g/L

6.6%

(–3.1% to 17.2%)

0.19

–