Iron deficiency anaemia in mothers and infants with high inflammatory burden: Prevalence and profile in a South African birth cohort

The scarcity of epidemiological data on anaemia in low- and middle-income countries, coupled with contrasting approaches to the assessment of iron status with inflammation, represent critical research gaps. This study characterised the prevalence and profile of iron deficiency anaemia, including adjustment for inflammation, in mothers and infants from South Africa. Mother-child dyads (n = 394) were recruited (2021-2022) for the Khula birth cohort in Cape Town. Haematological metrics, iron metrics, and inflammatory biomarkers were obtained from mothers antenatally and 3-6 months postnatally, and infants 3-18 months postnatally. The extent to which inflammation impacted iron deficiency was assessed using two methods; Method A: higher serum ferritin thresholds for classifying iron status in participants with inflammation (World Health Organisation), Method B: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anaemia (BRINDA) regression which corrects serum ferritin based on inflammatory biomarker concentrations. Prevalence of maternal anaemia was 34.74% (107/308) in pregnancy and 22.50% (54/240) in mothers at 3-6 months after childbirth. Of their infants, 46.82% (125/267) and 48.10% (136/283) were anaemic by 6-12 months and 12-18 months, respectively. Using Method A, the prevalence of maternal iron deficiency (regardless of anaemia), increased from 18.35% (20/109) to 55.04% (60/109) in pregnancy, and from 11.97% (28/234) to 46.58% (109/234) postnatally. Similarly, using Method B, maternal iron deficiency prevalence increased to 38.53% (42/109) in pregnancy, and 25.21% (59/234) postnatally. In infants at 12-18 months, the prevalence of iron deficiency increased from 19.79% (19/96) to 31.25% (30/96) and 32.29% (31/96) using Methods A and B, respectively. Approximately half of anaemia cases in mothers antenatally (50%; 20/40) and postnatally (45.10%; 23/51), and infants at 12-18 months (55.56%; 10/18), were attributable to iron deficiency. This is one of the first studies reporting the extent to which iron deficiency anaemia may be underestimated if inflammation is unaccounted for in South African mothers and infants.