Women and sleep: Changes throughout life

The onset of puberty introduces certain changes, such as menstruation, which can raise the likelihood of sleep disorders. For example, the risk of insomnia increases when menstruation begins. While the reason is still poorly defined, we believe it is linked with hormonal fluctuations that occur during the menstrual cycle.[1]

The negative effects of menstruation on sleep also appear to be most frequent during the last few days of a woman’s cycle, when levels of progesterone and estrogen decline.[2]

In addition, women who have irregular periods are twice as likely to have problems sleeping.[1]

During pregnancy, 30% of pregnant women report rarely getting a good night’s sleep, compared to 15% of women overall.[2]

The most common sleep disorders are anxiety, backache, fetal movements, breast tenderness, leg cramps, heartburn and abdominal discomfort.[2]

Sleep disorders may also be due to increased nighttime urination or restless leg syndrome, which is thought to be related to changes in the metabolism of iron and folate during gestation.[5]

Sleep patterns evolve during pregnancy. Although changes can be observed during the first two trimesters, the majority of sleep disorders appear to be most frequent during the third trimester.[3] At this stage, about 21% of women report that their sleep is disturbed to the point that a diagnosis of insomnia can be established.[2]

First trimester

• Time spent sleeping increases.
• Sleep efficiency decreases.
• Non-REM sleep (stages 1 and 2) increases.
• Number of awakenings after sleep onset increases.
• Daytime drowsiness increases.

Second trimester

• Sleep improves.
• Fatigue and daytime drowsiness decrease.

Third trimester

• Time spent sleeping decreases.
• Rapid eye movement (REM) sleep decreases.
• Sleep disruptions increase, with three to five awakenings per night.
• Daily napping increases.
• Daytime alertness decreases.
• Dreams are more disturbed.

Sleep disorders do not stop after a baby is born. A newborn’s sleep is highly irregular and it is not uncommon that a new mother must wake up during the night to care for or feed her child.

Studies have shown that during the first six months after birth, when the baby’s sleep is not yet regular, there is an increase in awakenings after the onset of sleep and a decrease in sleep efficiency compared to sleep during the third trimester of pregnancy.[2]

Poor sleep quality can also take its toll on the budding relationship between mother and newborn. Mothers who sleep poorly may perceive that their infants cry more and are more anxious. It has also been shown that poor sleep quality is a predictor of a weaker bond between mother and child.[2]

Parenthood can continue to be an obstacle to healthy sleep as the child gets older, especially for women. It is estimated that women shoulder nearly twice as much responsibility for child care as men.[7] This includes waking up during the night to care for family members.

This work can be highly detrimental to sleep consolidation and quality. While napping during the day or sleeping longer at night would improve the situation, mothers are not always able to do this due to family and professional responsibilities.

The growth of single-parent families is another factor contributing to women’s increased responsibilities. For example, it is believed that a significant number of women must meet the financial needs of their families through paid work, while also taking on the responsibility of unpaid work related to raising children.[7]

Sleep disorders have been identified as a major symptom of menopause.[2] In the U.S., the National Institutes of Health (NIH) estimates that 42% of women in premenopause, 47% in perimenopause, and 60% in postmenopause have this symptom.[8] Furthermore, a poll by the National Sleep Foundation found that 25% of perimenopausal and 30% of postmenopausal women report getting a good night’s sleep only a few nights per month.[2]

A woman becomes more prone to sleep disorders largely due to hormonal changes that occur during this time. However, aging also increases the risk of developing health problems (such as depression or sleep-disordered breathing), which contribute to poor sleep.

Vasomotor symptoms, also known as “hot flashes,” are one of the main obstacles to sleep during menopause. While the cause is not fully understood, it appears to be associated with a drop in levels of estrogen and other hormonal changes.

Hot flashes typically last for up to 30 minutes and are characterized by a feeling of intense heat, sweating and an elevated heart rate. They are estimated to occur in 60% to 80% of women during menopausal transition and persist for about four to five years on average.[2]

Hot flashes do not always cause sleep disruption, but this is often the case. Sleep fragmentation, increased waking after sleep onset and poor sleep efficiency have all been associated with hot flashes during actigraphy and polysomnography tests.[5]

In late menopause, when hot flashes appear to be most common, studies have shown that they significantly alter the quality of a woman’s sleep.[9] Vasomotor symptoms can also impact mental health, as links have been established with symptoms of depression.[6]

Insomnia is another common sleep disorder, affecting up to 36% of premenopausal and 61% of postmenopausal women.[3] This may be associated with hormonal changes, age-related changes in sleep, or the inability to fall back asleep after a hot flash. In addition, approximately 80% of menopausal women who experience severe hot flashes may suffer from insomnia.[1]

Although studies indicate that women tend to sleep longer than men, [7] their sleep is suspected to be less restful, which may have consequences for their health.

Research has shown that, compared to men, women who suffer from sleep disorders and insufficient sleep have a higher risk of depression, as well as metabolic and cardiovascular disorders.[11]

As a result, it is important that women pay attention to the quality of their sleep. If they suspect that poor sleep is disrupting their daily life, they should speak with their doctor. For their part, the medical community should also pay attention, as poor sleep can seriously affect a woman’s physical and mental well-being.