Pregnancy fatigue is one of the most common complaints in the first and third trimesters, and it’s driven by real physiological changes, not just poor sleep. The good news: a combination of eating strategies, movement, better sleep, and staying hydrated can meaningfully reduce how drained you feel. Some causes, like iron deficiency or thyroid problems, need medical attention rather than lifestyle fixes.
Why Pregnancy Makes You So Tired
Progesterone is the main driver. This hormone rises steadily throughout pregnancy, peaking in the third trimester, and it has a strong sedative effect. Your body is also building an entirely new blood supply, growing a placenta, and increasing your heart rate to keep up with demand. All of that takes energy, even when you’re sitting still.
Most people feel the worst fatigue in the first trimester, when progesterone is climbing rapidly and your body is adjusting to the new workload. The second trimester typically brings a noticeable energy boost. Then fatigue often returns in the third trimester, this time compounded by the physical weight you’re carrying, disrupted sleep, and the continued rise in progesterone.
Eat to Prevent Energy Crashes
Blood sugar swings are one of the biggest controllable causes of pregnancy fatigue. When you eat simple carbs alone (white bread, crackers, juice), your blood sugar spikes and then drops, leaving you wiped out. The fix is pairing carbohydrates with protein, fat, or fiber every time you eat. These slow down how fast sugar hits your bloodstream, keeping your energy more stable.
Aim for about 30% of your daily calories from protein, with a minimum of roughly 71 grams per day during pregnancy. Carbohydrates should make up 45 to 65% of your calories, but choose whole grains, legumes, fruits, and vegetables over refined options. A snack of apple slices with peanut butter, or cheese with whole-grain crackers, will carry you much further than a granola bar on its own.
Eating smaller meals more frequently (every two to three hours) also helps. Many pregnant people find that three large meals leave them sluggish, while five or six smaller ones keep energy steadier throughout the day.
Move More, Even When You Don’t Want To
It sounds counterintuitive, but moderate exercise is one of the most effective tools against pregnancy fatigue. Current guidelines recommend at least 150 minutes of moderate-intensity aerobic activity per week during pregnancy, spread across multiple days. That’s about 30 minutes, five days a week.
“Moderate intensity” means you can hold a conversation but not sing. Walking, swimming, stationary cycling, and prenatal yoga all count. You don’t need to push hard. Even a 10-minute walk after lunch can reduce that afternoon energy crash. The key is consistency: regular movement improves circulation, helps regulate your sleep-wake cycle, and builds the kind of stamina that makes daily tasks feel less exhausting.
Fix Your Sleep Setup
Poor sleep quality is a major contributor to daytime fatigue, and pregnancy creates plenty of obstacles: heartburn, hip pain, frequent urination, and difficulty finding a comfortable position. You can’t eliminate all of these, but the right setup helps.
In the first trimester, sleep in whatever position feels comfortable. By the second and third trimesters, side sleeping is ideal because it maximizes blood flow to your uterus. Left side is traditionally recommended, though sleeping on your right side is also fine. What you want to avoid, especially from week 28 onward, is sleeping flat on your back. That position puts pressure on major blood vessels and can reduce oxygen flow to the baby while causing dizziness and heartburn for you.
Strategic pillow placement makes a real difference. Place a pillow between your knees to ease hip and lower back pain. Elevate your upper body with a couple of pillows if heartburn is waking you up. A full-length body pillow can cradle your belly and support your back simultaneously, helping you stay on your side through the night. If you tend to roll onto your back, wedge a pillow behind you to prevent it.
Stay Hydrated
Dehydration causes fatigue in anyone, but during pregnancy your blood volume increases dramatically, so your fluid needs are higher than usual. ACOG recommends drinking 8 to 12 cups (64 to 96 ounces) of water every day during pregnancy. That’s roughly two to three liters.
If plain water feels unappealing, flavoring it with fruit or drinking herbal teas (check with your provider on which are safe) can help you hit your target. Front-load your water intake earlier in the day so you’re not chugging fluids before bed and waking up repeatedly to use the bathroom.
Use Caffeine Strategically
Caffeine is still an option during pregnancy, just within limits. The World Health Organization recommends keeping intake below 300 mg per day to reduce the risk of pregnancy loss and low birth weight. That’s roughly two to three standard cups of coffee. Some providers recommend a lower threshold of 200 mg, so check what your care team suggests.
Timing matters more than amount for fighting fatigue. A small cup of coffee in the morning or early afternoon can help you through the worst energy dips without disrupting your sleep. Avoid caffeine after mid-afternoon, since it takes about five to six hours to clear half of it from your system.
Check for Iron Deficiency
Iron-deficiency anemia is extremely common in pregnancy and causes fatigue that no amount of sleep or coffee will fix. Your body needs significantly more iron to support the increase in blood volume, and many people enter pregnancy with borderline iron stores.
The CDC recommends starting a low-dose iron supplement (30 mg per day) at the first prenatal visit as a preventive measure. If bloodwork shows anemia, treatment typically involves 60 to 120 mg of iron per day. Anemia is diagnosed when hemoglobin drops below 11.0 g/dL in the first and third trimesters, or below 10.5 g/dL in the second trimester. Your prenatal provider will check these levels routinely.
If you’re already taking a prenatal vitamin with iron and still feel crushingly tired, ask specifically about your ferritin level. Ferritin measures your iron stores, and it can be low even when your hemoglobin looks borderline normal. A ferritin level at or below 15 confirms iron deficiency. Pairing iron-rich foods (red meat, spinach, lentils) with vitamin C helps your body absorb more iron from both food and supplements.
When Fatigue Signals Something Else
Normal pregnancy fatigue is the kind where you feel tired but can push through your day with some adjustments. Fatigue that feels extreme, unrelenting, or comes with other symptoms may point to a thyroid problem. Hypothyroidism (underactive thyroid) causes intense exhaustion along with muscle cramps, constipation, trouble concentrating, and sensitivity to cold. These symptoms overlap significantly with normal pregnancy complaints, which is why thyroid issues are easy to miss.
Hyperthyroidism (overactive thyroid) can also cause fatigue, along with a racing heart and difficulty tolerating heat, both of which mimic normal pregnancy symptoms. If your fatigue feels disproportionate to what other pregnant people describe, or if it doesn’t improve at all during the second trimester when most people feel better, bring it up at your next appointment. A simple blood test can check your thyroid function, and treatment is straightforward if a problem is found. People with known thyroid conditions typically have their levels monitored every four to six weeks during the first half of pregnancy.