Why is the first trimester so tiring?

It is common to feel tired during pregnancy. Of course! You are growing a tiny human in your body. Levels of fatigue differ from person to person. Some people retain normal energy; some are tired for the full nine months. For most people, though, the first trimester is the one that causes the most fatigue. There is some return to normalcy in the second trimester, but the third trimester again shows signs of exhaustion.
The fatigue felt in your first trimester is a sign that your body is slowing down as it adjusts to the remarkable changes going on in early pregnancy. Your hormone balances are changing, especially progesterone levels, and these shifts are a major factor in your exhaustion. Progesterone increases dramatically in the first trimester.
Though your pregnancy is not yet visible physically, your body is experiencing dramatic changes. Your blood volume is increasing, and your heart rate is going up. The volume increase is due to the need to supply the growing placenta and support fetal circulation. The baby is only the size of a blueberry. It has grown from a single cell at fertilization to a fully formed fetus with hands and feet during the first trimester.
Low iron levels can also make you tired. This can surprise many women, especially first-time moms and those accustomed to having high energy levels. Women who only need a few hours of sleep at night often find they need to double that time during the first trimester. This can lead to exhaustion during the day and a need to nap. Nausea and vomiting, common symptoms found in the first trimester, can also lead to fatigue.
During the first trimester, the following changes happen to your body:
- Areolas on your breast will enlarge and may become bumpy
- Mammary glands grow and cause the breasts to become bigger and more tender
- Hormones cause moodiness
- The uterus grows and presses on the bladder
- Metabolism changes
- Intestinal muscle contractions can cause constipation, gas, and heartburn
All of these factors come into play, making your first trimester extremely tiring.
What happens during the second trimester?
Second-trimester pregnancy is usually much better for moms. There is less morning sickness — in most cases, it has disappeared. Second-trimester fatigue has eased up significantly compared to the first trimester, and breast tenderness decreases. These changes occur due to a decrease in the human chorionic gonadotropin hormone as the body adjusts to its new progesterone and estrogen levels.
Even though most of your fatigue will be gone by this time, your body is still undergoing significant changes. In the second trimester:
- You can feel quickening ?— the movement of the fetus — for the first time at 20 weeks
- The skin of your belly itches while it grows, and there is pain on the sides of the body as the uterus stretches
- At 20 weeks the uterus grows to belly button level, and your pregnancy is visible
- Congestion and nose bleeds can occur ?— your increased hormone levels increase blood flow to the nose and its membranes
- Increase in appetite
- Hormones cause an increase in blood flow to the gums, making them spongier and more likely to bleed
- Weight gain causes back pain
- Hyperpigmentation of the skin may occur on the face or abdomen because of increased hormone levels
Why does fatigue return in the third trimester?
You have had a fantastic second trimester, and now comes the third. With the arrival of the third trimester comes the return of fatigue. There are many reasons why you will again be tired in the third trimester:
- Insomnia from pregnancy and other symptoms: The huge baby bump, back pain, restless leg syndrome, and heartburn make sleep harder to come by.
- Continued baby growth: Your baby is rapidly getting large, and as a result, you are carrying around more weight than before in your pregnancy. Walking around with that extra weight can easily lead to fatigue.
- Multitasking: Job, household duties, extracurricular activities, kids — and now a growing baby adds more mental and physical exhaustion to the list.
- Stress from having a baby: At this time, the baby is almost here. Preparation, including the nursery, more frequent doctor visits, shopping for the baby, and just getting ready for the arrival can take away energy and make you tired.
Some people have strange dreams during pregnancy. They can have nightmares about the baby’s arrival or the actual labor and delivery process. No worries, this is normal due to hormonal changes.

SLIDESHOW
16 Early Signs & Symptoms of Pregnancy: Could You Be Pregnant? See SlideshowWhat can be done to feel better?
You can try several things to help you get better rest.
- If you find it hard to keep your eyes open during the day, try deep breathing exercises or stretches. Also, try getting up to walk around your location or take a break while at work to go outside.
- Eating well is important. Eat small, healthy, repeated meals to keep you going and aid in nausea prevention.
- Change your sleeping habits. During the day, take naps if you can. You could also try to get to bed earlier.
- Take quick walks around the block. Exercise up to your fitness level while pregnant can help you rest better at night.
- Drink plenty of fluids daily and decrease your intake approaching bedtime. This could help avoid getting up to go to the bathroom at night.
There are also things you should avoid. Do not overindulge on coffee or other caffeinated drinks to stay alert. Caffeine is not good for your growing child. Instead, try to drink lots of water. Sometimes you may feel bad about feeling lazy. It is ok. Now is the time to slow down and pamper yourself. During your first trimester, reducing any unneeded tasks or social events can help you be more productive in your necessary daily activities. And it will allow you to focus on your most important responsibility of all — growing a healthy and perfect little one.
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John Hopkins Health: "The First Trimester," "The Second Trimester."
Lamaze International: "How to Handle Fatigue in the First Trimester of Pregnancy."
National Health Service UK: "Tiredness and sleep problems. Is it normal to feel tired in pregnancy?"
University of Rochester Medical Center: "First Trimester Fatigue."
What To Expect: "Fatigue During Pregnancy."
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