Sleeping By the Trimesters: 3rd Trimester

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The third trimester is the most sleep challenged stage of pregnancy. With the frequency of urination, inability to get comfortable and exhaustion from trying to keep up with the demands of their normal schedules, some women find themselves struggling to stay awake. Hayley complained, "The third trimester was tough. I felt huge and could not get comfortable. I could hardly breathe because I started becoming asthmatic. Plus, the baby would kick at night causing me to wake up many times."

Back Pain, Muscle Aches and General Discomfort

In a study by the Department of Anesthesiology, Yale University School of Medicine, 950 pregnant women were surveyed about lower back pain during pregnancy, how it impacts day-to-day life and how their healthcare provider managed the pain. The study showed that 645 respondents reported back pain during their pregnancy and a majority claimed that it caused sleep disturbances.

These aches and pains can be associated with the ligaments between the pelvic bones softening and the joints loosening in preparation for the birth. Carrying the weight of the baby also affects posture, leaving many women uncomfortable walking, sitting, and sleeping.

Night Waking

Although studies show that women start waking up during the night at the onset of pregnancy, Dr. Mindell and Dr. Barry J. Jacobson's study "Sleep Disturbances During Pregnancy" show that by the end of pregnancy 97.3% of the women were waking at night - an average of 3.11 times each night. Two thirds of the women who woke up at night awakened five or more nights per week. Waking up multiple times may interrupt the necessary sleep cycles.


Many pregnant women start snoring because of nasal congestion, and the increase in abdominal girth and the uterus pressing on the diaphragm. About 30% of pregnant women snore because of increased swelling in their nasal passages, which can block airways. Snoring can also lead to high blood pressure, which can put both the mother and fetus at risk. If the blockage is severe, sleep apnea may result, characterized by loud snoring and periods of stopped breathing during sleep.

Women should consider snoring a warning sign, especially if it is in combination with severe daytime sleepiness, headaches and swollen legs. Dr. Jennifer Santiago of the Department of Obstetrics and Gynecology, New York Presbyterian Hospital, explained, "A recent study of 502 women reported that snoring pregnant women had a twofold greater incidence of hypertension, preeclampsia, and intrauterine growth restriction than did non-snorers."

Leg Cramps and Restless Legs Syndrome (RLS)

The National Sleep Foundation's 1998 Omnibus Sleep in America poll showed that up to 15 percent of pregnant women develop restless legs syndrome during the third trimester. The symptoms include crawling or uncomfortable feelings in the foot, calf or upper leg, momentarily disrupting sleep. Moving your legs can stop these symptoms temporarily, but the irritation returns when the limb is still.

Another study by Dr. Lee, "Restless legs syndrome and sleep disturbance during pregnancy: The role of folate and iron" looked at the likelihood of developing RLS during pregnancy. Dr. Kryger explains, "Those who developed restless legs syndrome were found to be iron deficient and/or folic acid deficient before becoming pregnant. So common sense mandates that women who develop RLS during pregnancy have their iron status checked by a doctor." The good news is that for most women, according to Dr. Kryger, restless legs syndrome goes away with childbirth.

Leg cramps in the lower leg muscles are fairly common in the second and third trimester. These painful spasms tend to occur at night and may disrupt your sleep. Leg cramps are believed to be caused by an excess of phosphorous and a shortage of calcium circulating in your blood system. trimester

Third Trimester Survival Tips

  • Sleep on your left side. This allows for the best blood flow to the fetus and to your uterus and kidneys. Try to avoid lying on your back for extended periods of time.
  • Try using a special "pregnancy" pillow to help you sleep better.
  • If you are experiencing leg cramps you may want to avoid carbonated sodas and drinks.
  • If you start snoring, have your blood pressure and urine protein checked—especially if you have swollen ankles and headaches.
  • If you develop Restless Legs Syndrome, you may want to talk to your health care physician about an iron deficiency.
  • If you can't sleep, don't lie in bed forcing yourself to sleep. Get up and read a book, write in a journal or take a warm bath.
  • If you get a cramp in your leg, straighten your leg and flex your foot upwards. Try doing this before going to bed several times to help ward off future cramps.