How Soon Can Headaches Start When Pregnant?

Headaches are one of the most commonly reported symptoms among pregnant women. There are a number of likely causes. Some are quite serious, but most pose little threat to the mother or child. If you are pregnant, always keep your doctor apprised of any complications or symptoms you are experiencing. A headache usually is nothing to worry about, but your doctor can tell you if your headache is the rare exception. Headaches can occur early or late in pregnancy, and the timing is one clue to the cause.

Caffeine Withdrawal

One frequent cause of headaches during pregnancy is caffeine withdrawal. A study published in the March 2008 issue of the "American Journal of Obstetrics and Gynecology" showed that expectant mothers who consumed 200 mg or more of caffeine a day had double the risk of miscarriage than those who consumed no caffeine. Many women choose to stop consuming caffeine cold turkey when they find out they are pregnant. Headaches from caffeine withdrawal can begin as soon as 12 hours after stopping consumption in regular caffeine users, although symptoms may take up to 36 hours. Headaches from caffeine withdrawal usually last between two days and one week.

Preeclampsia and Eclampsia

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Headaches that begin in the third trimester or, less frequently, late in the second trimester may be a symptom of preeclampsia and eclampsia. These pregnancy complications are potentially life-threatening to both mother and child. Headaches associated with these conditions are typically constant, as opposed to intermittent, and mild to severe in intensity. The headaches may be accompanied by pain in the upper middle region of the abdomen and visual disturbances. If you are experiencing these symptoms during pregnancy, you should inform your physician immediately.


Migraine headaches afflict about 18 percent of American women. Hormonal changes significantly influence the clinical course of migraines, and the hormonal changes associated with pregnancy are known to affect the incidence of migraines. The good news is that women with a previous history of migraines tend to experience a reduction of migraine incidence and severity, but this improvement usually takes place in the the second and third trimesters. Migraines that get worse, or those that occur for the first time in a pregnant patient with no previous history of migraines, most often do so during the first trimester or in the period immediately following delivery.

Tension-Type Headaches

Woman with hand on head

A Headache in the Back of the Head as Indicator of Pregnancy

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Tension-type headaches, or TTH, are the most common type of headache. They can occur at any point during pregnancy and are common in nonpregnant patients as well, afflicting 42 percent of all women. Usually described as a pressure or band-like constriction around the head, these headaches are more likely than migraines to worsen over the course of gestation but can be treated with a variety of medications that do not present a danger to the fetus.

Other Headaches

Idiopathic intracranial thrombosis is a rare disorder, symptoms of which include headaches that may worsen throughout the course of pregnancy. Headaches are also symptomatic of another rare disorder, cerebral venous thrombosis, which may manifest during pregnancy but more typically is seen in the first four weeks after delivery. Physicians recommend that women who experience a new-onset or worsened headache with increased frequency or severity, especially after the first trimester, should undergo additional diagnostic evaluation.