Iron status and risk factors of iron deficiency among pregnant women in Singapore: a cross-sectional study

BMC Public Health

Table 1 Maternal characteristics by iron status based on plasma ferritin concentrations in the GUSTO study (n = 985)

Characteristics	Total (n = 985)	Iron sufficiency (n = 258; 26.2%)	Modest iron depletion (n = 660; 67.0%)	Severe iron depletion (n = 67; 6.8%)	p^a
Age, %					0.044
< 25 years	12.8	10.1	12.9	22.4
25–34 years	65.3	64.0	66.2	61.2
≥ 35 years	21.9	26.0	20.9	16.4
Body mass index, kg/m²					0.410
Mean	23.6	23.6	23.6	24.4
Standard deviation	4.8	4.7	4.7	5.2
Body mass index, %					0.727
< 23 kg/m²	53.9	54.7	54.1	49.3
≥ 23 kg/m²	46.1	45.3	45.9	50.7
Ethnicity, %					< 0.001
Chinese	54.4	64.7	50.6	52.2
Malay	26.6	21.7	27.6	35.8
Indian	19.0	13.6	21.8	12.0
Education, %					0.016
None/Primary/Secondary	66.3	70.5	63.5	77.6
University	33.7	29.5	36.5	22.4
Parity, %					0.046
Nulliparous	42.5	48.8	40.0	43.3
Multiparous	57.5	51.2	60.0	56.7
Smoking status, %					0.751
No	97.5	96.9	97.7	97.0
Yes	2.5	3.1	2.3	3.0
Iron-containing supplementation, %					0.003
No	12.5	6.6	14.5	14.9
Yes	87.5	93.4	85.5	85.1
History of anaemia, %					0.952
No	94.8	95.0	94.7	95.5
Yes	5.2	5.0	5.3	4.5
Hemoglobin at early pregnancy^b g/dL					0.010
Median	11.9	12.3	11.8	11.8
Interquartile range	11.2–12.6	11.6–13.0	11.0–12.6	10.1–12.4
Anaemia at early pregnancy^b %					0.005
No	80.8	92.5	77.9	74.2
Yes	19.2	7.5	22.1	25.8
Plasma ferritin, μg/L					< 0.001
Median	24.2	36.2	22.6	12.3
Interquartile range	19.9–30.6	32.3–42.1	19.7–25.6	9.4–13.9
Plasma soluble transferrin receptor,^c nmol/L					< 0.001
Median	16.4	15.5	16.7	17.6
Interquartile range	14.3–19.7	13.6–18.2	14.4–20.0	15.0–21.6

GUSTO Growing Up in Singapore Towards healthy Outcomes. Values are presented as percentages for categorical variables, and median (interquartile range) for continuous variables. Iron sufficiency, modest and severe iron depletion are defined as having plasma ferritin concentrations of ≥30 μg/L, 15 to < 30 μg/L and < 15 μg/L, respectively
^ap values for differences between groups are obtained from Fisher’s exact tests for categorical variables, ANOVA or Kruskal-Wallis tests for continuous variables
^bData on hemoglobin concentrations and anemia at early pregnancy are only available for subsample of women, n = 422
^cData on plasma soluble transferrin receptor are only available for 977 women

ISSN: 1471-2458