Tap water consumption, showering, bathing and swimming during pregnancy in the born in bradford birth cohort

Publication authors

Smith R.B.; Edwards S.; Toledano M.B.; Nieuwenhuijsen M.; Wright J.; Raynor P.


Background: We are investigating disinfection by-product exposure during pregnancy and fetal growth in the large prospective multi-ethnic Born in Bradford (BiB) birth cohort. Many previous epidemiological studies have been limited by lack of data on individual water use behaviours and incomplete adjustment for potential confounders.

Objectives: To describe individual water consumption and water-related activities during pregnancy in the BiB cohort, and to examine variability of these behaviours according to demographic/lifestyle characteristics. Methods: At recruitment to the BiB cohort (around 28 weeks gestation) pregnant women completed a baseline questionnaire encompassing lifestyle, environment, ethnicity, and health, administered by interviewer. The questionnaire included questions on typical daily consumption of tap water, water filtering habits and frequency and duration of showering, bathing and swimming whilst pregnant. Patterns of tap water consumption, showering, bathing and swimming were analysed for 11,472 women in the BiB cohort.

Results: Preliminary results show that pregnant women in the cohort consume, on average, 1.6 litres of tap water per day with the majority of tap water consumption occurring at home regardless of employment status. On average, 22 minutes per day were spent showering and/or bathing. Only 7.3% of women reported swimming during pregnancy. Preliminary results suggest there are differences in tap water consumption and time spent showering/bathing according to ethnicity, smoking status and age.

Conclusions: Adverse fetal growth outcomes are known to be associated with ethnicity, maternal age and smoking, and our results suggest that future epidemiological analyses may need to be adjusted for these variables to avoid residual confounding.