Main adjusted analyses of shower length were also repeated, stratified by use of exhaust fans or leaving the window open during showers (Additional file 1: Table S6).
Furthermore, it is possible that there may have been some misclassification in our main exposure variables, as shower length was self-reported, potentially several months after pregnancy.
Main adjusted analyses of shower length were repeated again, stratified by presence of steam exhaust (use of an exhaust fan or leaving a window open during showers), because these activities are expected to decrease exposure to both hyperthermia and WDBPs.
Results from our evaluations of bath length and shower and bath frequency were less consistent than our main findings and did not support our shower length findings for most birth defects; however, because most women took one shower per day (68% of controls) and no baths (54% of controls), it is likely that these analyses were limited by the small amount of variability.
Main adjusted analyses were repeated based on several categories of longer shower length (i.e., 15 19, 20 29, and ≥ 30 minutes) (Additional file 1: Table S5).
To further assess the possibility that risk may vary among the offspring of women who took longer showers, the main adjusted analyses were repeated based on more specific categories of longer shower length (i.e., 15 19, 20 29, and ≥ 30 minutes).
As soon as they hit their teens, their shower length increases to nearly 10 minutes, which costs around £123 a year.
Table 3 Shower lengths and gaps between showers Parameter Min (min) Max (min) Mean (min) Standard deviation (min) Shower length 5158 8 4 Shower gap 5 7 6 1.
and details of hot water usages (e.g. average number of showers per day, average shower length etc). of the surveyed households.
Shower and bath length were categorized as <15 minutes or ≥15 minutes per occurrence, based on a median split of shower length among controls.
