Bladder Infections In Pregnancy

So you are pregnant.  At every OB visit, your doctor weighs you, checks your blood pressure, listens to your baby’s heartbeat and checks your urine.  Ever wonder why the urine is so important?  If you are not having symptoms of a bladder infection, what difference does it make?

Actually, urine gives a lot of information.  Your doctor checks for protein, glucose and bacteria.  And the bacteria can be there even if you don’t feel the burning and frequency of a urinary tract infection.  In fact, 5-10% of women have asymptomatic bacteriuria (ASB) at any time.  ASB is defined as greater than 10,000 bacteria in a single cc (just a few drops) of urine. 

Ordinarily this does not cause a problem.  But in pregnancy, the bladder empties less completely, the pH changes, and the ureters (drainage tubes from the kidneys to the bladder) expand.  The urine often contains more amino acids and sugar, which allow the bacteria to divide rapidly.  In fact, E.coli (the most common bacteria found in the bladder) can divide itself and thus double its numbers every eight minutes!  So in pregnancy, ASB can cause a symptomatic bladder infection fairly quickly if untreated.

Bladder infections are an uncomfortable nuisance.  But if untreated or incompletely treated, the infection can move upward, from the bladder into the kidneys.  A kidney infection is called pyelonephritis.  Pyelonephritis is much more severe than an ordinary bladder infection.  Symptoms include high fever (even to above 104 degrees in some cases), back pain and shaking chills.  Pyelonephritis in pregnancy typically requires an inpatient hospital stay, with intravenous fluids and antibiotics.  A few patients require an intensive care stay and oxygen therapy, and can have pre-term labor.  In a very small number the infection can be life threatening.

With potential complications like these, it’s easy to see why your doctor is so interested in your urine.  ASB is easily treated with antibiotic pills for 7-10 days.  Drinking plenty of water is also quite helpful.  Re-evaluation of urine at your next office visit usually confirms successful therapy.  So bladder health is an important aspect of a healthy pregnancy.  It’s no wonder your doctor is so interested in urine!

By Scott G. Williams, MD, FACOG of SSM St. Charles Clinic Medical Group, O’Fallon, MO.