Most women struggle with fatigue during pregnancy, especially during the first and third trimesters. During the first trimester, your body is supporting dynamic fetal growth and producing higher levels of progesterone, which has been linked to increased tiredness. If you're like many women, you'll feel more energy during most of your second trimester. Later in pregnancy, however, the physical demands of carrying a larger fetus, combined with disrupted sleep, can wear you out.
To manage fatigue during pregnancy:
WebMD Medical Reference from Healthwise