An analysis of intra-uterine growth retardation in rural Malawi

Objective: (1) To describe the sex-specific, birth weight distribution by gestational age of babies born in a malaria endemic, rural area with high maternal HIV prevalence; (2) to assess the contribution of maternal health, nutritional status and obstetric history on intra-uterine growth retardation (IUGR) and prematurity. Methods: Information was collected on all women attending antenatal services in two hospitals in Chikwawa District, Malawi, and at delivery if at the hospital facilities. New-borns were weighed and gestational age was assessed through post-natal examination (modified Ballard). Sex-specific growth curves were calculated using the LMS method and compared with international reference curves. Results: A total of 1423 live-born singleton babies were enrolled; 14.9% had a birth weight < 2500 g, 17.3% were premature (< 37 weeks) and 20.3% had IUGR. A fall-off in Malawian growth percentile values occurred between 34 and 37 weeks gestation. Significantly associated with increased IUGR risk were primiparity relative risk (RR) 1.9; 95% CI 1.4-2.6), short maternal stature (RR 1.6; 95% CI 1.0-2.4), anaemia (Hb < 8 g/dl) at first antenatal visit (RR 1.6; 95% CI 1.2-2.2) and malaria at delivery (RR 1.4; 95% CI 1.0-1.9). Prematurity risk was associated with primiparity (RR 1.7; 95% CI 1.3-2.4), number of antenatal visits (RR 2.2; 95% CI 1.6-2.9) and arm circumference < 23 cm (RR 1.9; 95% CI 1.4-2.5). HIV infection was not associated with IUGR or prematurity. Conclusion: The birth-weight-for-gestational-age, sex-specific growth curves should facilitate improved growth monitoring of new-borns in African areas where low birth weight and IUGR are common. The prevention of IUGR requires improved malaria control, possibly until late in pregnancy, and reduction of anaemia.