Sleeping for two: Sleep changes during pregnancy

Being pregnant can be a tiring experience for a woman’s body. Both the physical discomforts of pregnancy as well as the emotional stress of this major life change can cause sleep problems and keep a mother-to-be awake at night.

Feeling exhausted is a common complaint during the first and third trimesters. But women might be caught off guard by how worn out they feel in the early months of pregnancy.

“A lot of women are totally surprised by how fatigued they feel during the first trimester,” said Kathy Lee, a professor of nursing at the University of California San Francisco, who has studied how pregnancy affects sleep.
Women know about morning sickness in early pregnancy, but many first-time mothers say they had no idea about how tired they often feel at this stage, Lee said.

Sleeping for Two

Similar to the advice that a pregnant woman should be “eating for two,” health professionals should also be emphasizing the importance of “sleeping for two” during prenatal visits, Lee told Live Science.

One reason is that pregnancy can affect both the quantity of sleep a woman gets as well as the quality of it.

As their body changes and pregnancy discomforts make it more difficult to fall and stay asleep, mothers-to-be should spend at least eight hours in bed each night so they can get at least seven hours of sleep, Lee recommended.

Researchers have found that not getting enough sleep during pregnancy could affect a woman in ways that go beyond feeling exhausted during the day, irritability and poor concentration.

One of Lee’s studies, published in the American Journal of Obstetrics and Gynecology (AJOG), found that first-time mothers who got less than six hours of sleep at night were 4.5 times more likely to have a C-section, and their average length of labor was 10 hours or longer compared with first-time mothers who slept seven hours or more.

“A woman really needs to go to bed earlier when she is pregnant,” Lee said. Women need the extra rest, and they can’t keep going on the same amount of sleep they got before becoming pregnant, she pointed out.

Pregnancy and Fatigue

Researchers are still trying to figure out the exact reasons why pregnancy causes a woman to feel so exhausted, Lee said.

But to some extent, pregnancy-related fatigue is hormonal, she said. In the early phases of pregnancy, progesterone levels start to increase.

“Progesterone is a hormone that slows a woman down and mellows her out, and some women may perceive these effects as fatigue,” Lee said.

Besides the influence of hormones, some of the sleepiness that women feel early in pregnancy could also be physiological as the uterus gets bigger and the fetus grows, coupled with pregnancy-related weight gain and fluid accumulation in the body, Lee said. These changes mean the body is working harder as the placenta forms to nourish the developing fetus, the blood supply increases and the heart beats faster.

And emotional factors can also play a role. The excitement and anticipation of having a baby as well as the fears of impending motherhood and the anxiety about labor and delivery can all be stressful and make a woman feel more tired than usual.

Here’s what to expect in terms of sleep changes during the three stages of pregnancy.

Sleep and the First Trimester

In the early months of pregnancy, rising progesterone levels may not only make a woman feel drowsy, but they may also be partly to blame for the frequent need to pee, which can also disrupt sleep and worsen sleepiness.

During the first trimester, the hormones leading to the bladder get sluggish, which increases a woman’s urine production. This can cause her to wake up and need to go to the bathroom more frequently at night, Lee explained.

To reduce their nightly bathroom visits, women who are expecting may want to cut back on fluids in the evenings. However, they should not cut back on drinking plenty of fluids during the day because water and other liquids are important to help prevent constipation and excessive swelling, two common pregnancy discomforts.

Another factor that can rob a woman of the shuteye she needs is the nausea known as morning sickness, which can happen any time of the day or night. To relieve the queasiness, some women eat crackers or dry cereal before getting out of bed in the morning.

Women might also feel warm or hot when they sleep during pregnancy because of an increased metabolic rate, Lee said. A fan often helps to keep a woman cooler, she said, plus it can block out noise inside and outside the bedroom, including a snoring bed partner.

Bedmates are not the only ones who might be snoring. Snoring is common in pregnancy, and it can start in the first trimester in women who are already overweight or have allergies, Lee said.

Because of the many possible disruptions to sleep during pregnancy, napping is a good idea as long as a woman can fall asleep that night, Lee said.

But avoid using sleeping pills and even sleep-inducing supplements, such as melatonin, during pregnancy, Lee said.

Sleep and the Second Trimester

The second trimester of pregnancy is usually the best for women, Lee said. “Everything levels out and things aren’t changing quite as fast.”

Lee explained that hormonal changes, which are steep during the first trimester, level off during the second trimester, and then are steep again in the third trimester.

Leg cramps may occur at night during the second trimester. And some pregnant women, especially if they anemic and have low iron levels, may experience restless legs syndrome beginning in the evening hours of the second trimester and becoming more severe in the third trimester, Lee said. This condition, in which the legs feel jumpy, as if they had ants crawling up and down their veins, can occur while sitting or lying down and might be extremely uncomfortable.

Often the only relief from the pain is from walking around, Lee said, but then a woman may not be able to fall back asleep.

Heartburn is another problem that can keep women awake at night. As pregnancy progresses and a woman’s uterus gets bigger, it may press on her stomach, making a burning sensation more common.

Sleeping on the left side with the knees bent may be a better position for women who are experiencing heartburn during pregnancy, Lee said. Some women may also try sleeping with the head of the bed elevated or by propping their head on more pillows to ease the acid backwash of heartburn.

A lot of women say they have bizarre dreams related to their baby during pregnancy, Lee said. Although many women report strange dreams, the results from her research did not show any differences in dreaming across the trimesters compared with dreaming before a woman becomes pregnant.

“It might be that women are able to remember their dreams better during pregnancy because they are waking up more often,” Lee told Live Science.

Sleep and the Third Trimester

As a woman’s belly increases and the fetus is getting bigger and more active, Lee suggested that pregnant women sleep in any comfortable position they can find.

But she advised mothers-to-be to stay off their backs as much as possible because a heavy uterus can press on nerves in the spine and on a major vein that carries blood between the lower body and heart.

The National Sleep Foundation recommends that pregnant women sleep on their left side, which may improve the flow of blood and nutrients to the developing fetus and to a woman’s heart, uterus and kidneys.

Use pillows to be more comfortable, placing one between the knees, a second under the belly, and a third behind the back to support it and relieve pain, Lee advised.

Snoring is also a more common occurrence in the third trimester of pregnancy as a result of weight gain and more nasal congestion, Lee said. She recommended that women who have stuffy noses use nasal strips to help open up their nasal passages and improve their nighttime breathing.

One study found that women who began snoring while pregnant may be at greater risk of pregnancy-related high blood pressure and preeclampsia, a condition of high blood pressure during pregnancy, compared with mothers-to-be who did not snore.

by Cari Nierenberg, Live Science Contributor