What Does Protein in Urine During Pregnancy Indicate?

Expert: Christine Greves, MD

If you are pregnant or have been in the past, you’re likely well acquainted with the process of collecting a urine sample at prenatal visits. By the time you reach your third trimester, you’ve practically mastered the process and probably don’t think much of it anymore, but there is good reason for this routine (albeit unpleasant) sample collection—to test for proteinuria or protein in the urine. 

What Causes Protein in Urine During Pregnancy?

A simple urine test can clue doctors into all kinds of different things that may be happening inside your body during pregnancy. When it comes to protein, specifically, elevated levels can indicate things like urinary tract infections (UTI), preeclampsia, and kidney problems, according to Christine Greves, MD, an OB-GYN at Orlando Health Winnie Palmer Hospital for Women and Babies. Additionally, high levels of sugar protein could be a warning sign of gestational diabetes. 

Depending on your situation, to find out if your urine contains elevated protein levels, your doctor’s office will send your sample out to a lab for a complete analysis. This analysis will measure sugar levels, proteins, ketones, and bacteria. In some cases, the staff at your doctor’s office will also conduct a “quick dipstick test” before sending your sample to the lab. In this test, they’ll dip a test strip into the sample and wait to see what color the strip turns. Within minutes, the strip’s color will indicate whether protein levels in the sample are concerning. 

Symptoms of Protein in Urine During Pregnancy

Without a test, how will you even know if you have elevated protein levels in your urine during pregnancy? During the early stages of proteinuria, you may not experience symptoms at all. In fact, your urine test may be the first sign that anything is amiss. 

Still, this isn’t necessarily a symptomless event. In some cases, Dr. Greves says, “Symptoms can range between high blood pressure, swelling in hands and face, sudden weight gain, headache, visual changes, nausea and vomiting, and urinating more often.”  You may also notice fatigue, shortness of breath, and muscle cramps. 

 The cause of elevated protein levels in urine may present different symptoms. For instance, protein levels increase when a urinary tract infection (UTI) is present; you may experience the frequent need to urinate and possibly a burning sensation when you go.  In contrast, higher protein levels in the urine may cause significant swelling in the hands and face– common signs of preeclampsia. 

It’s also important to note that many of these symptoms are common pregnancy symptoms in general. There’s a good chance you experience a number of these symptoms throughout your pregnancy without ever having protein in your urine. 

What Happens Next

In most cases, the presence of elevated protein levels in urine alone is not enough to diagnose a single condition. Physicians will also consider symptoms (if you are experiencing any), and they may order additional tests to help narrow down the possible cause of the proteinuria. 

“Trends are very important in medicine,” explains Dr. Greves. “If we notice [protein] in your urine during pregnancy, we also check your blood pressure and assess your risks for other things.” Because these trends are so telling, Dr. Greves stresses the importance of keeping up with your regular prenatal checkups so that your provider has your history and data to reference. 

Once your doctor determines what is causing protein in your urine, they can assess the proper treatment. 

Learning about abnormal test results during pregnancy can be very scary, but it’s essential to stay calm and take things one step at a time with your health care provider. The best thing you can do for yourself and your baby is to keep on top of your prenatal appointments, pay attention to any strange symptoms you may be experiencing, and follow your doctor’s advice for a healthy pregnancy.