The study examined the relationship between sleep duration and cycle regularity among 2,596 women ages 18 to 50 who were not pregnant, not using hormonal contraception and not in peri/menopause. Researchers found that less sleep was associated with greater variability in cycle lengths.
Participants wore a wrist device connected to a smartphone app that collected sleep data and information such as resting heart rate variability, breathing rate, skin temperature and blood oxygen saturation. Researchers collected roughly 1.2 million days of data and recorded 42,759 menstrual cycles.
"This study shows an important association between lack of sleep and period regularity," said Dr. Lourdes DelRosso, Inspire Health Sleep Medicine director and a UCSF professor.
Dr. DelRosso emphasized that the findings show an association rather than a direct cause-and-effect relationship.
"Because there are many other factors and there could be social factors pain, discomfort, they could be stressors. It could be a lot of other factors that need to take into account the ability for this conclusion," Dr. DelRosso said.
According to the study, people who slept six hours tended to had more cycles that were off by three or more days from their normal cycle compared with those who slept eight hours. The findings also suggested that cycle lengths were more predictable among those who averaged more than 7.3 hours of sleep.
The American Academy of Sleep Medicine recommends at least seven hours of sleep for adults.
Dr. DelRosso said sleep needs are even greater for children and adolescents.
"It's about eight to nine hours, and sometimes even 10 hours for school-aged kids. It's important to get at least 10 or sometimes 11 hours. When you think of young girls and menses, when menses starts age 10 or 11, that recommendation is actually 10 hours of sleep. That's the time when the very early periods need to start getting regular, and you see a lot of irregularity. So it is important for parents to realize the importance of sleep for good and healthy hormone production and regularity," Dr. DelRosso said.
When asked whether people who have not been getting enough sleep can get back on track, Dr. DelRosso recommended maintaining consistent sleep habits.
"Keeping good sleep hygiene, consistent bedtime and wake-up time and avoiding electronics and bright light," Dr. DelRosso said.
Researchers also found a weak association between sleep duration and the actual length of the menstrual cycle.
For news updates, follow Danyelle Burke North on Instagram and TikTok.