The Woolcock Institute of Medical Research

Sleep is fundamental to physical health, emotional wellbeing and daily functioning, yet for many women, sleep difficulties remain poorly understood. Increasing evidence suggests that biological differences between men and women may influence how sleep disorders develop, present and respond to treatment. One important factor that has received surprisingly little attention is the role of reproductive hormones.

Throughout a woman’s reproductive years, the body experiences regular fluctuations in ovarian hormones that influence many aspects of health. These hormonal changes occur across the menstrual cycle, during the use of hormonal contraception, and across different stages of life. However, despite the fact that women may experience menstrual cycles for more than 35 years, and that hormonal contraception is widely used during reproductive years, we still know relatively little about how these hormonal changes affect sleep.

This lack of understanding has important implications. Conditions such as insomnia and obstructive sleep apnoea (OSA) affect many women, but symptoms may differ from those typically recognised in men, potentially contributing to delayed diagnosis or treatment. OSA is increasingly recognised as an important health issue for women, which presents differently to the way it does in men.

Despite growing awareness of sex differences in sleep health, the influence of menstrual cycle changes and hormonal contraception is still largely overlooked in sleep research and clinical practice.

Understanding how hormones interact with sleep disorders could help researchers and clinicians develop more personalised approaches to prevention, diagnosis and treatment — ensuring women’s sleep health is considered through a more complete biological lens.

Menstrual Cycle and Insomnia (MenscIS) Study

The MenscIS Study is investigating whether ovarian hormone fluctuations across the menstrual cycle, or the use of hormonal contraception, influence insomnia severity.

Participation is completely online and involves a set of baseline questionnaires and eight short surveys over a two-month period. Participants will receive reminders at each time point to help make the process simple and manageable. The study is seeking premenopausal women aged 18 to 40 who either experience a regular natural menstrual cycle or use hormonal contraception, and who report experiencing insomnia complaints.

MENSTRUAL OSA STUDY

The Menstrual OSA study aims to investigate whether OSA severity changes across different phases of the menstrual cycle due to natural fluctuations in ovarian hormones, and whether the use of oral contraception influences OSA severity.

The study involves 10 weeks of nightly at-home monitoring, daily diaries and oral temperature recording each morning to help identify menstrual cycle phases. At specific points during the menstrual cycle, participants will wear an oximeter ring to measure changes in blood oxygen levels during sleep.

By improving our understanding of the relationship between hormones and sleep, these studies aim to help develop more personalised approaches to the diagnosis and treatment of sleep disorders in women.

Find out more

• Our Sleep and Circadian Research group
• Register to volunteer for the MenscIS Study
• Register to volunteer for the Menstrual OSA Study