Anaemia and iron deficiency in pregnancy and adverse perinatal outcomes in Southern India

Abstract

Background/objectives: We examined the prevalence of anaemia, iron deficiency, and inflammation during pregnancy and their associations with adverse pregnancy and infant outcomes in India.

Subjects/methods: Three hundred and sixty-six women participating in a randomised trial of vitamin B₁₂ supplementation were monitored to assess haemoglobin (Hb), serum ferritin (SF), hepcidin, C-reactive protein (CRP), and alpha-1-acid glycoprotein (AGP) during pregnancy. Women received vitamin B₁₂ supplementation (50 µg per day) or placebo daily; all women received daily prenatal iron-folic acid supplementation. Binomial and linear regression models were used to examine the associations of maternal iron biomarkers with pregnancy and infant outcomes.

Results: Thirty percent of women were anaemic (Hb < 11.0 g/dl), 48% were iron deficient (SF < 15.0 µg/l), and 23% had iron deficiency anaemia at their first prenatal visit. The prevalence of inflammation (CRP > 5.0 mg/l: 17%; AGP > 1.0 g/l: 11%) and anaemia of inflammation (Hb < 11.0 g/dl, SF > 15.0 µg/l, plus CRP > 5.0 mg/l or AGP > 1.0 g/l: 2%) were low. Infants born to anaemic women had a twofold higher risk of low birth weight (<2500 g; risk ratio [RR]: 2.15, 95%CI: 1.20-3.84, p = 0.01), preterm delivery (RR: 2.67 (1.43-5.00); p = 0.002), underweight (WAZ < -2; RR: 2.20, 95%CI: 1.16-4.15, p = 0.02), and lower MUAC (β(SE): -0.94 (0.45)cm, p = 0.03). Similarly, maternal Hb concentrations predicted higher infant birth weight (p = 0.02) and greater gestational age at delivery (β(SE): 0.28 (0.08) weeks, p = 0.001), lower risk of preterm delivery (<37 weeks; RR: 0.76, 95%CI: 0.66-86, p < 0.0001); and higher infant MUAC (β(SE): 0.36 (0.13) cm, p = 0.006). Maternal SF concentrations were associated with greater birth length (β(SE): 0.44 (0.20) cm, p < 0.03). Findings were similar after adjusting SF concentrations for inflammation. IDA was associated with higher risk of low birth weight (RR: 1.99 (1.08-3.68); p = 0.03) and preterm birth (RR: 3.46 (1.81-6.61); p = 0.0002); and lower birth weight (p = 0.02), gestational age at birth (p = 0.0002), and infant WAZ scores (p = 0.02).

Conclusions: The prevalence of anaemia and iron deficiency was high early in pregnancy and associated with increased risk of adverse pregnancy and infant outcomes. A comprehensive approach to prevent anaemia is needed in women of reproductive age, to enhance haematological status and improve maternal and child health outcomes.

Fig. 1

Participant flow chart