Maternal micronutrient status and decreased growth of Zambian infants born during and after the maize price increases resulting from the southern African drought of 2001-2002

Objective: To investigate the effects on maternal micronutrient status and infant growth of the increased maize prices that resulted from the southern African drought of 2001-2002. Design: Longitudinal cohort study. Setting: A maternal and child health clinic in Lusaka, Zambia. Subjects: Maternal and infant health and nutrition data and maternal plasma were being collected for a study of breast-feeding and postpartum health. Samples and data were analysed according to whether they were collected before (June to December 2001), during (January 2002 to April 2003) or after (May 2003 to January 2004) the period of increased maize price. Season and maternal HIV status were controlled for in analyses. Results: Maize price increases were associated with decreased maternal plasma vitamin A during pregnancy (P=0.028) and vitamin E postpartum (P=0.042), with the lowest values among samples collected after May 2003 (vitamin A: 0.96 mu mol l(-1), 95% confidence interval (CI) 0.84-1.09, n=38; vitamin E: 30.8 mu mol mmol(-1) triglycerides, 95% CI 27.2-34.8, n=64) compared with before January 2002 (vitamin A: 1.03 mu mol l(-1), 95% CI 0.93-1.12, n=104; vitamin E: 38.9 mu mol mmol(-1) triglycerides, 95% CI 34.5-43.8, n=47). There were no significant effects of sampling date on maternal weight, haemoglobin or acute-phase proteins and only marginal effects on infant weight. Infant length at 6 and 16 weeks of age decreased progressively throughout the study (P-values for time of data collection were 0.51 at birth, 0.051 at 6 weeks and 0.026 at 16 weeks). Conclusions: The results show modest effects of the maize price increases on maternal micronutrient status. The most serious consequence of the price increases is likely to be the increased stunting among infants whose mothers experienced high maize prices while pregnant. During periods of food shortages it might be advisable to provide micronutrient supplements even to those who are less food-insecure.