Sleep and Women

In general, women tend to sleep more hours than men and sleep more deeply, although since this is frequently not continuous, they feel tired and sleepy when they wake up.

Sleep in women is very influenced by external and environmental factors such as tobacco, schedules, the existence of mood disorders, etc. At the same time, the hormonal changes that occur throughout a woman’s life can affect her sleep-wake rhythm and the characteristics of nocturnal sleep, showing the most striking impact at certain times of life.

Hormonal changes that occur during the menstrual cycle have consequences on women’s sleep.

We can divide the menstrual cycle in two periods:

• Follicular phase (from day 1 to 13 of the cycle, i.e. from the end of menstruation until the start of ovulation): At the end of this period there is a great increase in the secretion of estrogen.
• Luteal phase (from day 14 to 28 of the cycle, i.e., from ovulation to menstruation): There is an increase in the secretion of estrogen but more so of progesterone. The hormone progesterone causes sleep fragmentation, through both effects at the level of the brain centers of sleep regulation, and an indirect mechanism that causes an increase in daytime and nighttime body temperature. In turn, this causes an increase in daytime sleepiness.

A decline in the proportion of REM sleep and dreams in the days prior to menstruation has been observed. In addition, many women notice difficulty falling and staying asleep, which translates into a loss in the quality of sleep, though it usually has no significant impact during the day.

Some women suffer these changes exclusively or mainly in the area of sleep, presenting problems falling asleep for 3-6 days prior to menstruation, frequent nighttime awakenings, nightmares, and significant fatigue and daytime sleepiness. These difficulties disappear completely with menstruation.

Similarly, the quality and quantity of sleep can be affected negatively by factors associated with menstruation, such as menstrual pain or blood loss (which is associated with a decrease in the levels of iron in the blood, predisposing to restless leg syndrome) and cause sleep difficulty.

Trimester

First trimester:

This is a period of adjustment and assimilation to the new situation.

Pregnant women complain of increased sleepiness, probably in connection with the increase of progesterone (necessary for the development of the pregnancy), which, in addition to having this soporific effect, causes less deep sleep and more awakenings throughout the night, resulting in a lower quality of sleep and daytime tiredness.

There are also other factors that can influence sleep:

• Back pain and body changes.
• Increased frequency of urination: Consequence of the secretion of the hormone that lowers the tone of the bladder muscles.
• Nausea and vomiting: Although in the majority of cases their emergence occurs mainly during the morning, in some cases it can appear at any time, and can even be responsible for pregnant women rising early when they are woken by feelings of nausea.

Second trimester:

The main problems are:

• Burning sensation (from gastroesophageal reflux), mainly in the supine position since the organs in the abdominal cavity move to make room for uterine growth.
• Body movements.
• Nightmares.

Third trimester:

This is the most critical period for sleep. The most common problems are a consequence of:

• Back, muscle pain or general malaise: These are common in this period due to the posture that the mother adopts during the pregnancy because of the weight of the child and the preparation of bones and ligaments of the pelvic waist for the time of birth.
• Frequent nighttime awakenings and more superficial sleep.
• Increase in the frequency of urination: Due to the growth of the uterus that compresses the bladder.
• Snoring: Snoring can be a consequence of the increasing abdominal perimeter and the pressure of the uterus on the diaphragm, which may be associated with air flow problems due to nasal congestion. Pregnant women who snore may also have sleep apnea, which is generally attributed to being overweight and the factors previously mentioned. A proper assessment is necessary since there is a higher incidence of hypertension, preeclampsia, and delayed intrauterine fetus growth in pregnant women who snore, which poses a risk to the mother and child.
• Restless legs syndrome: It is estimated that up to 15% of women present restless legs syndrome during pregnancy, mainly those who have low iron and folic acid iron levels since pregnancy causes an increase in the demand for iron. In almost all cases, the disorder disappears after childbirth.
• Painful leg cramps: These appear in the second trimester of pregnancy, usually during the night, and can disrupt sleep. They are painful contractions in the distal muscles of the leg.