In a retrospective analysis of 158 women considered to have had normal, low-risk pregnancies, 30 gave birth to infants with a birthweight less than the 10th centile for gestation. These 30 women had a significantly poorer mean increase in weight (0.99 kg) between 28 and 32 weeks gestation than the other 128 women (1.95 kg) who gave birth to infants with birthweights above the 10th centile for gestation. There was no statistically significant difference in booking weight, overall weight gain or other variables associated with low birthweight between the two groups of women which suggests that poor maternal weight gain specifically between 28 and 32 weeks gestation may predict small-for-gestational-age infants.