TABLE 4d.

Associations between maternal iron status at early and mid-pregnancy with heart rate in late pregnancy (multivariable linear regression).

Gestational age	Predictor	Heart rate (bpm)
		Model 1 (n = 189)			Model 2 (n = 184)			Model 3*
		B	95% CI	p	B	95% CI	p	B	95% CI	p
< 18 weeks	Hb (g/dL)	0.56	−0.50, 1.62	0.295	0.45	−0.66, 1.55	0.425	-	-	-
	Fer (μg/L)	−0.02	−0.03, 0.00	0.023	−0.02	−0.03, 0.00	0.041	-	-	-
	sTfR (mg/L)	0.09	−0.11, 0.29	0.364	0.11	−0.08, 0.31	0.254	-	-	-
		Model 1 (n = 189)			Model 2 (n = 186)			-
22 weeks	Hb (g/dL)	−0.32	−1.41, 0.77	0.568	−0.21	−1.31, 0.89	0.710	-	-	-
	Fer (μg/L)	−0.03	−0.06, 0.01	0.112	−0.02	−0.05, 0.01	0.123	-	-	-
	sTfR (mg/L)	0.08	−0.24, 0.39	0.640	0.07	−0.24, 0.38	0.664	-	-	-

CI, confidence interval; Hb, haemoglobin; Fer, serum ferritin; sTfR, soluble transferrin receptor. Associations were assessed with multivariable linear regression, B-values and 95% confidence intervals. Model 1 is adjusted for maternal age and living standards measure (socio-economic status); model 2 is adjusted additionally for gestational age, CRP and maternal BMI at baseline, HIV status throughout pregnancy and aspirin prescription during mid-pregnancy;

^*, model 3, not conducted. p < 0.05 was considered significant and p between 0.05 and 0.08 had a tendency towards significance.