Generational changes in young adults' sleep duration: a prospective analysis of mother-offspring dyads

To quantify the changes in sleep duration over two generations of young adults.

We used data from the Mater-University of Queensland Study of Pregnancy cohort to compare sleep duration in mother and offspring. The analyses were restricted to 1,731 mothers who were young adults (mean age 21.96 years; SD±1.90) at the baseline measurement, and their offspring who were about the same age (mean age 20.6 years; SD±0.86) when assessed 21 years later. Maternal sleep was explored by asking the mother, during the first trimester, about her typical sleep duration prior to pregnancy, while offspring participants were asked about the sleep duration in the last month at the time assessed. Multinomial logistic regression for correlated responses was used to assess generational changes.

We found that offspring had 3.2 (2.7, 3.9) times the odds of sleeping for short duration (≤6 hours/night) and 1.7 (1.5, 1.9) times the odds of sleeping for a longer duration (≥9 hours/night) compared with their mothers. Gender-based analysis found that daughters had 3.0 (2.3, 5.0) times the odds of sleeping for a short duration, while sons had 3.4 (2.6, 6.4) times the odds of sleeping for a short duration compared with their mothers.

There is a significant decline in sleep duration below recommendations as well as a substantial increase in long-duration above the recommendations over two generations of young adults. Therefore, the focus of sleep health should not be limited to short sleep, but on the need for achieving optimal sleep recommended for the age.