Temporal change in maternal dietary intake during pregnancy and lactation between and within 2 pregnancy cohorts assembled in the United Kingdom

Background: The association between maternal and infant dietary exposures and risk of allergic disease development is an area of considerable scientific uncertainty.
Objective: This study aims to compare dietary habits during pregnancy and lactation in two pre-birth cohorts from the same location approximately 10 years apart, a timeframe characterised by changes in government dietary advice.
Methods: The FAIR cohort is an unselected birth cohort born between 2001-2002. The 3rd generation cohort was born between 2010-2018. Both cohorts were established on the Isle of Wight (UK) to investigate prevalence of allergic diseases. Nutrition and allergy data was collected prospectively from recruitment and throughout the infant’s early life. Here we present dietary data collected in the third trimester of pregnancy and at three months of age. Differences between cohorts were tested using t-tests, Wilcoxon rank sum tests, chi-squared and Fisher’s exact tests.
Results: Data was available for 1331 participants (969 FAIR and 362 3rd generation). The proportion of mothers that reported excluding peanuts during pregnancy was significantly lower for the 3rd generation compared to the FAIR cohort (16.0% vs. 55.6%, p < 0.01). Cohort membership, primiparity, and maternal education were significantly associated with excluding peanuts during pregnancy (p < 0.01). The proportion of mothers who reported excluding any foods during breastfeeding was significantly lower for the 3rd generation compared to the FAIR cohort (22.8% vs. 43.4%, p < 0.01).
Conclusion: Maternal exclusion of peanut during pregnancy was lower for mothers giving birth between 2012-2018, compared to mothers giving birth between 2001-2002.