During a routine return OB visit, an 18-year-old G1P0 patient at 23 weeks gestational age undergoes a urinalysis. The dipstick done by the nurse indicates the presence of trace glucosuria. All other parameters of the urine test are normal. Which of the following is the most likely etiology of the increased sugar detected in the urine?

The finding of glucosuria is common during pregnancy and usually is not indicative of any pathology. During pregnancy, there is an increase in the glomerular filtration rate and a decrease in tubular reabsorption of filtered glucose. In fact, one of six women will spill glucose in the urine during pregnancy. If the patient has risk factors for diabetes such as obesity, previous macrosomic baby, advanced maternal age, or family history of diabetes, the physician may want to screen for diabetes with a glucose tolerance test. If the patient has a urinary tract infection, the dipstick will also show an increase in WBCs and blood. A contaminated urine sample would not be a cause of isolated glucosuria.