Fatigue or feeling like you are tired is a common symptom of pregnancy.  Some women describe this as a lack of energy or being lethargic.  Your fatigue will not harm the baby in any way and it makes for a great excuse to take a nap.

What causes fatigue during pregnancy?

There is a combination of factors that contribute to your fatigue or lack of energy.  First, there is a rapid shift of hormones that triggers several changes in your body.  Your blood volume and circulation are both increasing.  You have a developing baby and enlarging uterus. And, you have just the normally demands of day to day activities.  All of these take energy and you only have so much to go around.

When do these changes occur?

Some people even report fatigue before they have missed a period.  However, this symptom most commonly occurs in the first trimester around six to eight weeks.

How frequently do they occur?

The majority of women report fatigue in some sort of fashion.  Usually the difference is found in the intensity or duration of fatigue.  Some women feel bouts or momentary fatigue where others report feeling sluggish all day long.  It is common for fatigue to be experienced throughout your pregnancy.


Cunningham, F., MD; Leveno, K., MD; Bloom, S., MD; Hauth, J., MD; Gilstrap, L., MD; and Wenstrom, K., MD, Williams Obstetrics 22nd ed., McGraw-Hill, New York, 2005.

Duff, P., MD, Edwards, R., MD, Davis, J., MD, Rhoton-Vlasak, A., MD, Obstetrics and Gynecology: Just the Facts, McGraw-Hill, New York, 2004.

Scott, J., MD; Gibbs, R., MD; Karlan, B., MD; and Haney, A., MD, Danforth’s Obstetrics and Gynecology, 9th ed., Lippincott Williams & Wilkins, Philadelphia, 2003.

Crombleholme, W., MD, “Obstetrics,” Current Medical Diagnosis & Treatment 2003, 42nd ed., McGraw-Hill, New York, 2003.

DeCherney, A., MD, and Nathan, L., MD, Current Obstetric & Gynecologic Diagnosis & Treatment, 9th; McGraw-Hill, New York, 2003.

Harms, R., MD, Mayo Clinic Guide to a Healthy Pregnancy, HarperResource, New York, 2004.

Bankowski, B. MD., Hearne, A. MD, Lambrou, N. MD, Fox, H. MD, and Wallach, E. MD, The Johns Hopkins Manual of Gynecology and Obstetrics, 2nd ed., Lippincott Williams & Wilkins, Philadelphia, 2002.

American College of Obstetricians and Gynecologists, Planning Your Pregnancy and Birth, 3rd ed., ACOG, Washington DC, 2000.

Beck, W., MD, Obstetrics and Gynecology, B.I. Waverly Pvt., Ltd., New Delhi, 1997.

Johnson, R., MD, Mayo Clinic Book of Pregnancy & Baby’s First Year, William Morrow and Company, Inc., New York, 1994.