Symptom guide · Pregnancy Smart
Blood in urine during pregnancy
By trimester
Weeks 1–13
1st trimester
Early pregnancy raises the same urinary tract infection risk that continues throughout pregnancy, and a stone or infection found now gets worked up the same way it would at any other point. True blood in the urine is never explained away as just early pregnancy.
Weeks 14–27
2nd trimester
As the growing uterus starts to press on the bladder and ureters, urinary tract infections become more common, and MedlinePlus lists infection of the bladder or kidney among the main causes of visible or microscopic blood in urine. Report new or ongoing symptoms rather than waiting for your next routine visit.
Weeks 28–birth
3rd trimester
Later in pregnancy, always rule out vaginal bleeding before assuming a urine sample's blood is truly urinary, since NIDDK notes blood that looks like it's in the urine can actually be coming from the vagina. A clean-catch sample and a conversation with your provider can sort out which it actually is.
What does the evidence show for blood in urine?
- Blood in urine can come from a problem in the kidneys or urinary tract, such as infection of the bladder, kidney, prostate, or urethra, from a bleeding disorder, or it may not be urinary at all: MedlinePlus notes what looks like blood in urine can actually be coming from the vagina. 1
- MedlinePlus advises contacting your provider right away for blood in urine accompanied by fever, nausea, vomiting, shaking chills, or pain in the abdomen, side, or back, and states plainly that you should never ignore blood you see in your urine. 1
- NIDDK defines hematuria as blood in the urine, either gross hematuria that is visible to the naked eye or microscopic hematuria detectable only through a urine test, with common causes including infection, urinary tract stones, vigorous exercise or sexual activity, and recent urinary procedures or trauma. 2
- Assessment typically starts with a medical history, physical exam, and urinalysis to confirm blood is actually present, and depending on findings can include blood tests, ultrasound, CT scan, cystoscopy, or kidney biopsy, per NIDDK. 2
- MedlinePlus notes most causes of blood in urine aren't serious, including certain medications, intense physical activity, and even foods like beets or rhubarb, but the same source lists urinary tract or kidney infection, kidney or bladder stones, and kidney inflammation among the more significant possible causes that a positive test should prompt follow-up on. 3
- A case report describes placenta percreta, a rare condition where the placenta grows through the uterine wall and can invade the bladder, causing visible blood in the urine. The same report notes placenta percreta itself is rare, affecting an estimated 0.3 to 1 in 10,000 births, with hematuria described as an uncommon presenting sign even within that small group. 4
Blood in urine during pregnancy: what it could mean
| Pattern | Possible cause | What to do |
|---|---|---|
| Blood plus burning, urgency, or frequent urination | Urinary tract infection | Contact your provider for testing; UTIs are common in pregnancy and respond well to prompt care |
| Blood plus sharp flank or back pain | Kidney stone or kidney infection | Contact your provider; fever with this pattern needs prompt evaluation |
| Blood that may actually be vaginal in origin | Vaginal bleeding rather than true hematuria | Mention exactly what you observed and when; a clean-catch urine sample can help sort this out |
| Any visible blood in urine, even once | Several possible causes, most identifiable with testing | Never ignore it. Get a urinalysis rather than waiting to see if it happens again |
When should I call my provider about blood in urine?
Fever, chills, nausea, vomiting, or pain in your abdomen, side, or back alongside blood in your urine needs same-day medical attention, per MedlinePlus, since this pattern can point to a kidney infection rather than a lower urinary tract problem alone. Heavy or repeated visible blood, or blood clots with pain, also deserves prompt evaluation rather than a wait-and-see approach: blood in urine should never be ignored or assumed to resolve on its own. Trust your read on your own body. If something feels off beyond the list above, please consult your healthcare provider rather than waiting it out.
Frequently asked questions
What does blood in urine during pregnancy usually mean?
Most often it points to a urinary tract issue like infection or a stone, though NIDDK also lists vigorous exercise, sexual activity, and recent urinary procedures as common, less serious causes. A urinalysis is how your provider narrows this down rather than guessing from symptoms alone.
Could it actually be vaginal bleeding instead of blood in my urine?
Yes, and this is a genuinely common mix-up. MedlinePlus specifically notes that blood which looks like it's in the urine can actually be coming from the vagina, so telling your provider exactly what you noticed and when helps sort out which it really is.
Is blood in urine during pregnancy an emergency?
Not always, but it should never be ignored. MedlinePlus specifically advises contacting your provider right away if blood in urine comes with fever, nausea, vomiting, shaking chills, or pain in the abdomen, side, or back.
What is the difference between gross and microscopic hematuria?
Gross hematuria is blood you can actually see, often turning urine pink, red, or brown. Microscopic hematuria is only detectable through a lab urine test, per NIDDK, which is why a routine urinalysis can pick up blood you wouldn't otherwise notice.
Can a urinary tract infection cause blood in urine during pregnancy?
Yes. Infection of the bladder or kidney is listed by MedlinePlus among the main causes of blood in urine, and urinary tract infections are common during pregnancy as the growing uterus puts more pressure on the bladder and ureters.
What tests will my provider run if I have blood in my urine?
NIDDK describes a medical history, physical exam, and urinalysis as the starting point, with additional tests like bloodwork, ultrasound, a CT scan, or cystoscopy added depending on what the initial results and your symptoms suggest.
Can exercise cause blood in urine during pregnancy?
It can. NIDDK and MedlinePlus both list vigorous physical activity among the recognized, usually benign causes of hematuria. Still, any blood in urine deserves a mention to your provider rather than being assumed to be exercise-related without testing.
Is blood in urine ever caused by something related to the placenta?
Rarely. A case report describes placenta percreta, where the placenta grows through the uterine wall and can invade the bladder, as a rare cause of visible blood in urine. Placenta percreta itself is uncommon, affecting an estimated 0.3 to 1 in 10,000 births, so this is a small piece of a much larger list of possible causes, not the first thing to assume.
Related in the library
References
MedlinePlus · https://medlineplus.gov/ency/article/003138.htm
Hematuria (Blood in the Urine)
NIDDK · https://www.niddk.nih.gov/health-information/urologic-diseases/hematuria-blood-urine
MedlinePlus · https://medlineplus.gov/lab-tests/blood-in-urine/
Gross Hematuria in Pregnancy: An Enigma
PMC · https://pmc.ncbi.nlm.nih.gov/articles/PMC6765036/
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