Maternal preconceptional weight and gestational length

Recent animal studies suggest that preconceptional undernutrition shortens gestation. We retested this idea among rural Gambian women who experience annual fluctuations in energy balance caused by the rains (with lowest weights in September to November) using records from 1918 infants. Pregnancies conceived in September to November were significantly shorter than those from better-fed months (38.6 vs 39.0 weeks; log-rank χ2 = 17.4, P < .0001).