You'll have a urine test at your first prenatal visit and at later visits, too. The urinalysis tests for sugar, protein, ketones, bacteria, and blood cells to make sure you don't have a condition such as a UTI, gestational diabetes, or preeclampsia.
Will my practitioner ask me for a urine sample at each prenatal visit?
Maybe. Practices vary a lot from office to office, and your provider will be testing for different things at different points in pregnancy.
Your practitioner will likely ask you for a urine sample at your first prenatal visit and send it to a lab for a complete urinalysis and possibly culture (to check for bacteria). Some practitioners will continue to ask for a urine sample at each visit (or once a trimester), and they will usually test it by dipstick right in the office. Others will not ask for a sample again unless you're having symptoms that would warrant a urine test.
Some will give you specific instructions for how to produce a "clean-catch midstream specimen," while others will just ask you to pee a little bit into a cup.
How do I produce a "clean-catch midstream specimen"?
You're given a specimen cup and an antiseptic wipe and sent to the rest room to produce a urine sample.
- Wash your hands.
- With clean fingers, separate your labia and clean your vulva from front to back with the wipe.
- Urinate for a few seconds into the toilet, and then slip the cup under the stream until you collect enough for the sample. (Avoid touching the inside of the cup with your fingers.) Then finish urinating into the toilet.
- Put the cap on the cup and deliver it to the medical assistant.
How is the dipstick testing done?
A medical assistant checks your urine by dipping a colored test stick in it and comparing the results to a chart. The results are written on your medical chart for your midwife or doctor to review.
What is my urine tested for?
It's normal to occasionally have a small amount of sugar (glucose) in your urine during pregnancy, but if you have elevated levels at a couple of prenatal visits in a row or a very high level at one visit, it could mean you have gestational diabetes.
Your practitioner may have you take a glucose challenge test to find out whether that's the case. (Even if your urine test results are normal, you'll have a glucose challenge test between 24 and 28 weeks to check for this relatively common condition.)
Excess protein in your urine can be a sign of a urinary tract infection (UTI), kidney damage, or certain other disorders. Later in your pregnancy, it can also be a sign of preeclampsia if it's accompanied by high blood pressure.
If you have protein in your urine but your blood pressure is normal, your provider may send a clean-catch midstream sample to the lab in a sterile container to test for a UTI.
Ketones are produced when the body starts breaking down stored or ingested fat for energy. This can happen when you're not getting enough carbohydrates (your body's usual source of energy). It can also be a sign that you're dehydrated.
If you're suffering from severe nausea and vomiting or you've lost weight during pregnancy, your practitioner may check your urine for ketones. If your ketone reading is high and you can't keep any food or liquid down, you may need intravenous fluids and medication. If ketones are found in combination with sugar in your urine, it could be a sign of diabetes.
Bacteria and blood cells
On your first prenatal visit, your urine sample will most likely be screened for bacteria that indicate a UTI. This is done through a laboratory urinalysis and a culture and sensitivity test. The culture shows any bacteria and isolates it, and the sensitivity test shows which antibiotics can effectively treat the infection.
The test is done even though you may not have symptoms of a UTI. (While UTIs usually cause painful symptoms when you're not pregnant, it's possible to have a UTI with no symptoms during pregnancy.) If left untreated during pregnancy, even a painless, symptomless UTI can progress to a full-blown kidney infection, which almost always requires hospitalization. So screening is done at the beginning of pregnancy to catch and treat a UTI early.
If this initial test is negative, your risk of developing a UTI later in pregnancy is small, unless you have a history of chronic or recurrent UTIs.
You may continue to have dipstick tests during your pregnancy or you may only have one if you show symptoms. The dipstick test checks for a certain enzyme (produced by white blood cells) and nitrites (produced by certain bacteria), both of which signal a UTI. If either of these shows up on a dipstick test, a sterile urine sample will be sent to the lab for a culture and sensitivity test.
You usually have to wait about 48 hours for the results of a urine culture and sensitivity test. However, your practitioner may start you on some kind of antibiotics before the testing is complete, particularly if you have symptoms of a urinary tract infection.
You'll be tested again after treatment of a UTI and at regular intervals during your pregnancy if your provider feels you're at risk for recurrent UTIs. In addition, if you have a history of kidney infection or frequent UTIs, your provider may recommend a mild daily antibiotic during pregnancy to prevent infection.
In addition to a urine test, you'll also have blood tests at your first prenatal visit. Our article on common first trimester blood tests explains what those are looking for.