Pregnancy fatigue is caused by a surge in progesterone, increased blood volume, and the body’s added energy demands, plus disrupted sleep.
Why
- Progesterone surges, which is sedating.
- Blood volume rises by up to 50%.
- The body works hard to support the baby.
- Low iron or anemia.
- Sleep disruption.
When
Peaks in the first trimester and returns in the third.
Relief
- Sleep more and nap.
- Eat iron rich foods.
- Gentle exercise.
- Hydrate.
See a doctor
If fatigue is extreme, or comes with dizziness, or shortness of breath.
Hormone and blood changes
Fatigue is among the most common early pregnancy symptoms. Progesterone rises sharply and acts as a sedative. Blood volume increases by 30 to 50 percent by the third trimester, and the heart pumps more blood, which is tiring. Iron needs increase from 18 mg to 27 mg per day.
- Fatigue often peaks in the first trimester, eases in the second, and returns in the third.
- Anemia affects roughly 1 in 5 pregnant women in the US, and causes extra tiredness.
- Sleep disruption from nausea, bathroom trips and discomfort adds to fatigue.
- Thyroid problems and gestational diabetes can also cause tiredness.
Relief
Nap, go to bed earlier, eat small frequent meals with protein and iron, walk lightly and drink water. Take prenatal vitamins as directed. Ask a doctor to check hemoglobin and thyroid function if fatigue is overwhelming. Seek help for fatigue with shortness of breath, palpitations, persistent low mood or hopelessness, which may signal anemia or depression.
Hormone and blood changes
Pregnancy fatigue is driven by rapid rise in progesterone, increased blood volume (about 40 to 50 percent), the energy cost of growing a baby, sleep disruption and low iron. Anemia occurs in about 38 percent of pregnant women worldwide, according to the WHO.
Relief
Rest, eat iron rich foods, stay active lightly and drink water. Ask a provider to check hemoglobin, thyroid and vitamin D. Severe fatigue with palpitations or breathlessness should be checked.
Changes in the body
Blood volume increases by about 1.5 liters during pregnancy, and the heart pumps 30 to 50 percent more blood. Progesterone has a sedative effect. Iron needs increase from 18 to 27 mg a day. Iron deficiency anemia affects about 18 percent of pregnant women in the US. Thyroid disorders and gestational diabetes cause fatigue too.
Management and screening
Providers screen hemoglobin at the first visit and at 24 to 28 weeks, along with a glucose test. Eat iron rich foods (red meat, beans, fortified cereals) with vitamin C, take prenatal vitamins and nap 20 to 30 minutes. Light exercise such as walking 150 minutes a week boosts energy. Report depression symptoms, which are common and treatable.
Based on data from the American College of Obstetricians and Gynecologists and the CDC
