Why Is Pregnancy So Tiring?

You're in the first trimester of pregnancy and you're probably asking yourself"why is pregnancy so tiring?" Here's what you need to know.
Why Is Pregnancy So Tiring?

Last update: 02 August, 2022

Many women who are pregnant for the first time ask the same question: Why is pregnancy so tiring? When you’re going through the first months of pregnancy, you feel tired no matter what you do–or don’t do. This happens to all of us, to women who are usually full of energy, and to those who’ve always had the habit of taking an afternoon nap. When we’re pregnant, we end up drained of energy and with a sleepiness that seems to have no explanation.

Among the most common symptoms during pregnancy is feeling intense and seemingly inexplicable tiredness, which is often accompanied by excessive sleep.

The first weeks of pregnancy can be terrible. That’s because, in addition to feeling tired and sleepy, it’s also very common for nausea and vomiting to wreak havoc on your body and your energy levels. But take heart, this doesn’t last forever. At the end of the first trimester, the symptoms disappear and you’ll feel fine again.

However, this relief is temporary because your body feels fatigued again during the third trimester when the baby is already very large, and consequently, your belly as well. At that stage, your body carries at least 22 pounds more than its usual weight. So, as you’ll see, there are plenty of reasons to be sleepy when you’re pregnant and they’re not random. They all have a reason.

A pregnant couple sleeping in bed.

Why is pregnancy so tiring?

The tiredness and sleepiness you experience when your baby is growing inside your belly are largely due to the hormonal and physiological changes that your body begins to experience in the first weeks of pregnancy.

Among the hormones that revolutionize your body during pregnancy, progesterone is the one that stands out the most. Its levels suffer an increase of more than 500% and its action is essential for the maintenance of pregnancy and for the development of your baby. However, the rise in its levels causes many side effects, the main one being the feeling of extreme tiredness and excessive sleepiness.

In the first weeks of pregnancy, your body, in addition to providing the necessary nutrients for your baby to develop, needs to produce the placenta that will nourish your child during pregnancy. This process requires a lot of energy and makes your body prioritize the development of the pregnancy to the detriment of your daily activities.

The growth of the placenta also consumes energy

The baby and the placenta also need blood and much of your blood flow is destined for this new being that’s developing. In addition to the detour of blood, pregnancy hormones also stimulate a decrease in blood pressure caused by vasodilation of the arteries.

So, pregnant women have lower blood pressure. Much of the body’s blood is destined to irrigate an area of tissue that’s larger than usual, that area where the love of your life is gestating.

At the same time, fluid retention thins the blood, making pregnant women relatively anemic. This contributes even more to the tiredness and intolerance we feel at this stage of our life towards physical efforts.

At the end of the first trimester, hormone levels stabilize and the placenta is already formed, so tiredness and sleepiness improve considerably. During this period, many women feel as energetic as ever. That’s why the second trimester is known as the happy trimester because all those unpleasant symptoms that appear in the first weeks of pregnancy go away.

As your baby grows, so does the tiredness

But the story doesn’t end there. We often feel tired again during the third trimester, when our body begins to feel that it’s carrying excess weight.

Your baby alone weighs about 6.5 pounds, while body water and amniotic fluid are estimated at just over 13 to 18 pounds, and the placenta together with the uterus weighs almost 4.5 pounds. Therefore, at the end of pregnancy, each mother carries about 22 pounds more than she used to carry just a few months ago.

So, during pregnancy, your body assumes a significant weight gain in a very short interval and doesn’t have much time to adapt. In addition, progesterone also acts on the muscles, tendons, ligaments, and joints of the body, altering their normal functioning. This makes you more prone to pain and musculoskeletal injuries.

A father kissing his parther's pregnant belly as they both lie on a chalk drawing of a bed.

Why is pregnancy so tiring during the third trimester?

The feeling of being very sleepy comes back in the third trimester of pregnancy. This happens not only because of the direct action of progesterone on the central nervous system but also because the large size of your belly prevents you from getting a good night’s sleep.

In the final stage of pregnancy, sleeping on your back or stomach is impossible, and in fact, it’s not recommended that you sleep on your stomach. Ideally, you should spend the whole night on your side, and in fact, when you get comfortable, it’s very likely that you’ll stay that way for the rest of the night because, at this point in your pregnancy, you feel have a very hard time changing positions while you sleep.

To make matters worse, the action of progesterone and the compression of the bladder by the uterus make you feel the urge to urinate all the time. Sometimes you will need to get up more than once during the night to go to the bathroom, which further disrupts your sleep.

So, in addition to all the fatigue accumulated throughout the day from excess weight, aches, and pains, frequent urges to go to the bathroom, and difficulty breathing (due to a giant uterus compressing the diaphragm), every pregnant woman still struggles to replenish her energy during nighttime sleep.

As you can see, there are numerous answers to the question why is pregnancy so tiring? But experiencing all these discomforts will be worth it because, after 9 months, you’ll have your newborn baby in your arms.

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