Objective: To study seasonal variation of maternal anthropometry and newborn weights.
Design: A retrospective descriptive study from 1995 to 1998.
Setting: Lungwena, a rural health centre in Malawi, southeast Africa.
Subjects: One thousand and thirty two women with singleton pregnancy, a minimum of eight weeks antenatal follow-up and a baby who was weighed in the first month of life. Maternal data were sought from a health centre antenatal register and linked with infant information collected from a newborn clinic.
Results: The mean (SD) gestational weight and fundal height gains among the pregnant women were 240 (200) grams and 0.9 (0.2) cm/week and the mean (SD) newborn weight 3360 (530) grams. Gestational weight gains followed a seasonal pattern and they were typically highest among women delivering in the third quarter of the year (mean gain 250-300 g/week) and lowest among those delivering in January-May (mean gain 100-200 g/week) (p < 0.001 for seasonality, ANOVA). For maternal fundal height gains and newborn weights, seasonality was less obvious (but statistically significant, p < 0.05, ANOVA) and its pattern was influenced by year of study. On average, newborn weights peaked in the last quarter (mean 3350-3400 grams) and nadired during the second quarter (mean 3200-3300 grams). There was only a modest correlation between maternal weight gain in pregnancy and the weight of her newborn (Pearson's correlation coefficient 0.13).
Conclusion: In rural Malawi, maternal weight gains during pregnancy are more strongly associated with season than fundal height gains or newborn weights. In adverse environmental conditions, foetal growth ismaintained at least partially at the expense of mother's nutritional status.