To investigate the association of seasonality with dietary diversity, household food security and nutritional status of pregnant women in a rural district of northern Bangladesh.

A cross-sectional study was conducted from February 2013 to February 2015. Data were collected on demographics, household food security (using the Household Food Insecurity Access Scale), dietary diversity (using the women’s dietary diversity questionnaire) and mid-upper arm circumference. Descriptive statistics were used to explore demographics, dietary diversity, household food security and nutritional status, and inferential statistics were applied to explore the role of seasonality on diversity, household food security and nutritional status.

Twelve villages of Pirganj sub-district, Rangpur District, northern Bangladesh.

Pregnant women (n 288).

Seasonality was found to be associated with dietary diversity (P=0·026) and household food security (P=0·039). Dietary diversity was significantly lower in summer (P=0·029) and spring (P=0·038). Food security deteriorated significantly in spring (P=0·006) and late autumn (P=0·009).

Seasons play a role in women’s household food security status and dietary diversity, with food security deteriorating during the lean seasons and dietary diversity deteriorating during the second ‘lesser’ lean season and the season immediately after. Interventions that aim to improve the diet of pregnant women from low-income, subsistence-farming communities need to recognise the role of seasonality on diet and food security and to incorporate initiatives to prevent seasonal declines.