One of the most common side effects of pregnancy is headache. For some women, this troublesome symptom is one of the first clues they have that they're pregnant. Mild headaches plague many women throughout pregnancy, and the causes can vary from trimester to trimester. Regardless of the cause, the Mayo Clinic recommends relaxation, plenty of sleep and relaxing massage to ease symptoms. While some obstetricians allow pregnant women to take certain over-the-counter analgesic drugs, the generally mild headaches of pregnancy often respond to home remedies, notes Mayo.
Changing Hormones
In their book, "What to Expect When You're Expecting," Heidi Murkoff and Sharon Mazel note that one of the causes of headache early in pregnancy is changing hormone levels. During the first trimester a woman's body is adjusting to high levels of progesterone and the pregnancy hormone, hCG. These hormones affect the way her body functions significantly---they change blood flow patterns, they affect sleep cycles and they can even change the alignment of vertebrae in her back. All of these have the potential to cause headaches. For most women, though, these early headaches disappear at some point during the first trimester as the body adjusts to the new hormones and begins to compensate.
Dehydration
Newly pregnant women have a tremendously increased need for water, as compared to before their pregnancies. While non-pregnant women may do well on eight 8-oz. glasses of water a day, a pregnant woman may need up to 13. If she doesn't drink enough water, she can easily become dehydrated, which decreases blood volume and pressure, potentially causing a headache. Staying hydrated is one of the best ways to prevent pressure-related headaches. Unfortunately, pregnant women also experience a need to urinate frequently, and drinking plenty of water certainly doesn't help her stay out of the bathroom. Still, it's important to drink lots of water---despite the frequent urination---in order to maintain health and prevent uncomfortable headaches.
Back Strain
Late in pregnancy, the weight of the developing fetus and all its accoutrements (the uterus, now much larger than in a non-pregnant woman, the amniotic fluid and the placenta) add as much as 30 lbs. to a woman's frame. This weight is all in the front of the body, throwing her balance off, and pulling her back out of its normal alignment. This can put stress on the muscles of the lower back, which in turn pull on the muscles of the upper back. The upper back strain pulls the shoulders out of alignment, and this cascade of muscle tension, in the end, produces significant tension in the muscles of the neck that extend up into the head. For late-pregnancy headaches in particular---because they're largely muscular in origin---attention to posture and massage are quite helpful, note Murkoff and Mazel.
References
- "What to Expect When You're Expecting"; Heidi Murkoff and Sharon Mazel; 2008
- Mayo Clinic: Pregnancy Headaches
