The study involved 400 Swedish women; they were between 20 and 70 years of age. Their sleep was monitored by home sleep testing.
Results show that they slept for only about 6.5 hours per night. It took the women an average of 22 minutes to fall asleep.
Participants slept on their side for 50 percent of their total sleep time; side sleeping was more common in women over the age of 45 years.
The women slept on their back 41 percent of the time; only nine percent of total sleep time involved stomach sleeping.
In women who were older and in those with high blood pressure, sleep efficiency was lower. This is the percentage of time in bed that you are asleep. A low efficiency means that you were awake for much of your time in bed.
Older women and those with a higher body mass index (BMI) had less of the sleep stages of deep, slow-wave sleep. Sleep quality also was reduced in women who smoke, drink or have high blood pressure; it took them longer to fall asleep.
The AASM reports that there are many complex factors that can affect how a woman sleeps. These include sleep disorders, medical problems, pregnancy and menopause.