Sleep During Pregnancy: Trimester by Trimester

If you're pregnant, you've probably noticed some changes in your sleeping habits. Here you can find out why and how to improve your sleep.
Sleep During Pregnancy: Trimester by Trimester

Last update: 22 July, 2021

We’re used to living for ourselves. Our body working in tune with our mind in order to meet the needs of perfect machinery. But one day we stop being and living only for ourselves and we start hosting another life inside of us. Among the many things that happen to our bodies, changes in sleep during pregnancy will be one of the most relevant aspects.

Even if adapting to this phenomenon is quite difficult, we should know that there’s a biological reason that we’ll probably understand after pregnancy.

How does sleep change during pregnancy?

Trimester by trimester, the pregnant body adapts to living for two (and sometimes more than two). These changes are gradual but significant, as doubling energy requires a greater effort.

The mother’s body undergoes major changes to accommodate a new life. One of the biggest challenges she faces is the creation of a new organ responsible for mediating the exchange of oxygen and nutrients between the baby and its mother: the placenta. This involves an enormous expenditure of maternal energy from the beginning of gestation, which translates into a greater need for rest.

Pregnant woman napping due to sleep changes.

Sleep during pregnancy: first trimester

This stage is determined by hormonal and circulatory changes that occur as a result of the creation of the placenta. This organ demands a lot of energy, so the body goes into a kind of “energy saving mode”. All vital processes slow down in order to prioritize the baby’s development.

It’s to be expected that during this trimester, pregnant women feel more tired during the day. Also, they experience a desire to sleep at times when they used to be quite active.

In addition to hormonal changes, the loss of water and salts that occur through vomiting favors a state of dehydration. The same occurs with increased urinary frequency. All these changes increase the need for rest.

Recommendations to improve rest during this stage

  • Maintain daily activities, but adjusting intensity according to the possibilities.
  • Ensure a healthy and complete diet and sufficient hydration.
  • Continue with the usual physical activity.
  • Rest at least eight hours at night and add a daytime nap if possible.

Sleep during pregnancy: second trimester

This stage is characterized by a state of balance between mother and baby. This is known as Bar’s state of Harmonic Symbiosis. In the majority of cases, the pregnant mother enters a stage of well-being during which she feels more energetic to carry out her activities. In other cases, nausea and vomiting persist, and this equilibrium takes longer to arrive.

Around the fourth month of gestation (or earlier if you’ve already had children), the mother’s abdomen shows signs of her baby’s growth. The same happens inside this cavity. All abdominal organs have to make space for the growing uterus and adapt to the reduced space available:

  • The bladder and ureters become compressed, favoring increased urinary frequency (which is known as pollakiuria), mainly at night (nocturia).
  • The stomach and intestine reduce their usual movement, which results in gas retention and increased gastroesophageal reflux. All this causes a feeling of fullness after eating, increased acidity, and abdominal discomfort.
  • The diaphragm tends to ascend and reduce the expansion space of the lungs, favoring the sensation of shortness of breath.

Recommendations to improve rest during this stage

  • Eat light meals, especially at dinner.
  • Go to bed at least two hours after eating.
  • Urinate before going to sleep.
  • Avoid lying on your stomach.
  • Ensure a comfortable position in bed with pillows or cushions.

Sleep during pregnancy: third trimester

At this stage, the mother’s body has started all the adaptive changes and begins to prepare for the baby’s arrival. One of the most notable transformations at this time is the onset of insomnia. According to the American Academy of Sleep Medicine, insomnia is: “The subjective perception of difficulty in sleep onset, duration, consolidation, or quality that occurs despite adequate opportunity for sleep, and results in some form of daytime disturbance.”

Woman falling asleep during pregnancy.

Even if this phenomenon occurs due to changes in brain activity, which seek to prepare the mother for the state of nocturnal semi-alertness that she’ll experience after birth, it’s not the only cause. There’s a relationship with other factors:

  • Emotional: anxiety and the desire to meet her baby.
  • Mechanical: the heaviness of the belly, the need to constantly change position, and the compression of the viscera of the body, among others. They generate pain, cramps, frequent urination, and shortness of breath, among others.
  • Baby factors, which maintain a certain level of activity taking advantage of the lying maternal position that provides more space.

Recommendations to improve rest during this stage

  • Rest on the left side (this frees the inferior vena cava and facilitates blood flow to the baby).
  • Use pillows to support the belly and avoid lumbar discomfort.
  • Drink enough water during the day and maintain a low sodium diet (due to the increased fluid retention at the end of the pregnancy).
  • Look for relaxing and “unplugged” activities to practice before going to sleep (meditation, yoga, listening to music, reading a book, sharing a moment with your partner).
  • Try to sleep at least eight hours a day. Changing sleep hours could favor an increase in blood pressure and the risk of pre-eclampsia.

All in all, we hope this information about sleep changes during pregnancy is helpful. However, if you have any doubts, it’s always advisable to consult your doctor for advice.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Uranga Imaz F, Uranga Imaz F (h). Obstetricia Practica, 5° Edición. Editorial Inter Medica. Buenos Aires. 1985.
  • Sateia MJ, Buysse DJ, Krystal AD, Neubauer DN, Heald JL. Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline. J Clin Sleep Med. 2017 Feb 15;13(2):307-349
  • Michelle A WilliamsRaymond S MillerChunfang QiuSwee May CripeBizu GelayeDaniel Enquobahrie. “Associations of early pregnancy sleep duration with trimester-specific blood pressures and hypertensive disorders in pregnancy”. Sleep 2010 Oct;33(10):1363-71. doi: 10.1093/sleep/33.10.1363.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.