Causes Of A Urine Odor During Pregnancy

Pregnant women notice changes in urine early on. For some women, these changes are as simple as needing to go much more frequently than usual. Others find that in addition to frequency, they also notice an odd smell associated with the urine. There are several potential causes of odd-smelling urine during pregnancy, some of which are completely normal and related to hormones, and others of which have to do with infection.

Changing Nasal Sensitivity

Aside from more frequent urination, pregnant women experience a host of other symptoms, one of the most troublesome of which is an exceedingly enhanced sense of smell. This is a product of pregnancy hormones--a vastly increased blood supply as well as simply changes in physiology cause women to smell odors much more strongly, and in much lower concentration, than they normally do. In their book "What to Expect When You're Expecting," Heidi Murkoff and Sharon Mazel point out that women may simply notice the smell of urine much more strongly than they used to, and that what a woman perceives as an unusual urine odor may simply be the normal smell of urine, greatly amplified.

Pregnancy Hormones

The urine of pregnant women contains substances not normally found in urine--that's the reason a home pregnancy test can use urine to confirm the presence of a baby. The hormone hCG, which is produced by the developing embryo's growing placenta, makes its way into the mother's bloodstream, and from there into her urine via the kidneys. Some women are able to smell the hormone on their urine, and note that it has an odd odor.

Urinary Tract Infection

Unfortunately, though many pregnant women experience both frequent urination and unusual urine odors as normal symptoms of pregnancy, these are also both symptoms of urinary tract infection, notes Dr. Miriam Stoppard in her book, "Conception, Pregnancy and Birth." It can be quite difficult to tell normal pregnancy urine odor from the slight odor associated with urine in the case of an infection, and the frequent need to eliminate common to infections is also easy to mistake for normal pregnancy frequency. If urine odor is accompanied by a cramping sensation in the pelvis, although this, too, is common in pregnancy, and a burning sensation upon elimination, it's possible that the odor is caused by a urinary tract infection. Such infections are quite common during pregnancy, notes Dr. Raymond Poliakin in "What You Didn't Think To Ask Your Obstetrician," but thankfully there are several antibiotics approved for use in pregnant women that can quickly resolve the issue.