During pregnancy, the body transforms to accommodate a new life, and with this, certain balances also change, which can favor urinary tract infections. Although these are often mild, detect them early and treat them safely It is key to prevent them from getting worse or affecting maternal-fetal well-being.
If you experience discomfort when urinating or have bacteria detected in a test despite having no symptoms, you're not alone: ​​it's quite common. The important thing is knowing what signs to watch for, when to see a doctor, and what habits can help. With the right approach, The vast majority of urinary tract infections during pregnancy resolve without putting the baby at risk..
Why are urinary tract infections more common during pregnancy?
The hormonal and mechanical changes of this stage explain much of the increased risk. Progesterone relaxes the muscles of the ureters and bladder, slows the flow of urine, and makes it easier for residual urine to remain after urination; in addition, the growing uterus compresses the bladder. All of this creates an ideal environment for bacteria such as Escherichia coli, responsible for most urinary tract infections.
Anatomy isn't the only factor at play. Vulnerability is greater during the first six months of pregnancy, so it's important to be especially careful with hydration and hygiene. In terms of frequency, Two out of ten pregnant women may experience a urinary tract infection throughout pregnancy, and a significant portion will have bacteria in their urine without symptoms.
One particular point is asymptomatic bacteriuria (bacteria in the urine without symptoms). It affects approximately 2-11% of pregnant women, and if left untreated, between 20-40% of cases (in some studies, 30-35%) can progress to symptomatic infection or reach the kidneys. This is why prenatal screening is recommended. even if you feel perfectly fine.
Common symptoms and warning signs
Cystitis (bladder infection) presents with very characteristic symptoms. If these appear, You need to consult to confirm with an analysis. and receive safe treatment.
- Burning or pain when urinating (dysuria) and a feeling of urinary urgency.
- Frequent urge to urinate even if only a few drops come out (pollakiuria).
- Suprapubic discomfort or pressure and in the lower abdomen.
- Changes in urine: cloudy or milky, strong ammonia smell in urinedarker color or with mucus.
- Possible blood when wiping after urinating or visible hematuria.
- Pain during sexual intercourse and a feeling of not fully emptying.
- In some cases, inability to urinate normally or a change in the amount of urine.
Sometimes there are no symptoms, but prenatal testing detects bacteria. This absence of discomfort does not diminish its importance. Asymptomatic bacteriuria must be treated to avoid complications later on.
If the infection ascends to the kidney and pyelonephritis develops, the condition is more aggressive and requires immediate attention. Warning signs include: high fever (peaks that can reach 39-40°C), chills, profuse sweating, intense pain in the lower back (predominantly on the right side in up to 90% of cases), nausea and vomiting with difficulty hydrating, and a decline in overall health. If you experience these symptoms, go to the Emergency Department without delay..
To give you some context: cystitis usually causes discomfort when urinating, bladder tenesmus, and suprapubic pain; pyelonephritis adds high fever, flank pain, and general malaise. It can be bilateral (in approximately 25% of cases), and around 80% of pyelonephritis cases are caused by... E. coliPyelonephritis in pregnancy requires hospitalizationespecially if there is a temperature >38 ºC or signs of dehydration.
Impact on pregnancy: Can it affect the baby?
Most urinary tract infections resolve well with appropriate treatment and follow-up. However, when they go undiagnosed or untreated, certain risks increase: premature birthLow birth weight and, in severe cases, perinatal morbidity/mortality are common complications. These complications are drastically reduced with early detection and safe antibiotics.
For the newborn, untreated maternal infections can be associated with a higher risk of neonatal infection (e.g., UTI, sepsis) and problems common in low birth weight infants, such as respiratory difficulties or slower development. In the mother, a poorly controlled infection can become recurrent, requiring prolonged antibiotic courses and higher likelihood of long-term urinary tract complications.
The good news is that, with prenatal checkups and prompt action, the prognosis is excellent. In fact, with the right approach, A UTI shouldn't harm you or your baby..
How it is diagnosed: urine test and urine culture
The diagnosis combines basic urinalysis and culture. The physical-chemical examination assesses specific gravity, pH, appearance and color, and parameters such as nitrites, hemoglobin, protein, glucose or acetone, in addition to the urinary sediment (leukocytes, bacteria, hematuria). Leukocyturia and positive nitrites suggest infection quite reliably.
In urine sediment, the presence of leukocytes is a useful marker: low values ​​(e.g., 4-8 leukocytes per field) may suggest relative control, while higher values ​​point to active infection. These ranges are indicative; the definitive interpretation is made by the healthcare professional based on the complete set of tests. Don't self-medicate based on a single piece of information.
Urine culture is the gold standard test. It allows for the identification of bacteria and the study of resistance patterns to adjust the antibiotic. A positive result is defined as more than 100.000 CFU/ml of a single microorganism; counts between 10.000 and 100.000 or the presence of multiple species require repeating the sample. The antibiogram guides the most effective and safe treatment..
For reliable results, collection must be done carefully: wash hands and clean the genital area; collect the first urine of the morning if possible; discard the first stream and collect the midstream in a sterile container. If not processed immediately, it can be stored at 4°C for up to 24 hours. A properly taken sample avoids false positives due to contamination.
Guidelines recommend performing a culture at the first prenatal visit. With this strategy, less than 1% of pregnant women with an initial negative culture will subsequently develop bacteriuria. Furthermore, after treating an infection, a follow-up culture is usually ordered between 7 and 15 days later, and if pyelonephritis was present, monthly follow-up with urine cultures until delivery.
Safe treatment during pregnancy
The golden rule is simple: always consult a doctor and avoid self-medication. The primary treatment consists of pregnancy-safe antibiotics, selected based on culture and sensitivity testing. Complete the instructions exactly as directed.even if the symptoms improve within a few days.
For uncomplicated cystitis, a 7-day course of antibiotics is usually prescribed. If pyelonephritis is present, management is hospitalized with intravenous antibiotics and monitoring of vital signs; after clinical improvement and 48-72 hours without fever, it is common to switch to oral antibiotics to complete the course. This strategy reduces relapses and protects kidney function.
In addition to medication, there are supportive measures that help: drinking enough water (at least 8 large glasses a day, and generally 2-3 liters spread out), rest, compatible painkillers to relieve pain, and, if recommended by your healthcare professional, warm compresses on the lower abdomen. Hydration helps clear bacteria from the urinary tract.
Important: If symptoms do not improve within 48 hours of starting antibiotics, if a high fever develops, or if you have difficulty staying hydrated due to vomiting, go to the Emergency Department. After completing treatment, a follow-up urine culture is usually ordered to confirm eradication; some complex cases require urological evaluation after delivery. Follow-up prevents recurrences and complications.
Action plan according to the type of infection
Every diagnosis has its own roadmap. Tailoring the plan to the specific scenario improves the resolution and prevents problems. The most suitable itinerary Your healthcare team will tell you.
Asymptomatic bacteriuria
Present in 2-11% of pregnant women, it should be treated even in the absence of symptoms, as 20-40% (30-35% in some series) progress to overt infection if left untreated. Antibiotics are prescribed based on culture and sensitivity testing, and urine culture is repeated after treatment. If it persists, monthly check-ups can be done until delivery..
Acute cystitis
It affects approximately 1-4% of pregnant women, most frequently in the second trimester. It is recommended to take a sample for culture before starting the treatment regimen, which often lasts 7 days and is adjusted when the results are received. Starting treatment early shortens the duration of symptoms and limits progression.
Pyelonephritis
With an incidence of around 1-2%, this is the severe form and requires hospitalization. Management includes intravenous antibiotics, hydration, close monitoring, and, after 48-72 hours without fever and with good progress, transition to oral intake. Pyelonephritis in pregnancy cannot wait..
Follow-up after treatment
Monitoring is part of the treatment: a follow-up urine culture between days 7 and 15 after completing the course, and monthly cultures if pyelonephritis occurred. In patients with complications, a urological evaluation after delivery may be recommended. Preventing relapses is just as important as curing the current episode..
Daily habits that help prevent
Prevention is your best ally. With small routines, you can greatly reduce the risk of infection. They are simple and make all the difference.
- Constant hydration: 2-3 liters daily, spread throughout the day (and at least 8 large glasses).
- Don't hold back the urge to urinate and try to empty your bladder; always urinate after sexual intercourse.
- Intimate hygiene: clean only the external area with pH neutral soaps, from front to back, without sponges or gloves (they can accumulate bacteria), and dry thoroughly.
- Wear loose-fitting cotton underwear and change it daily; avoid tight-fitting garments that retain moisture.
- A diet rich in vitamin C fruits (citrus fruits, kiwi), yogurt with probiotics, plenty of fiber to avoid constipation, and less refined sugar (helps prevent candidiasis).
- Avoid bladder irritants such as caffeine and alcohol, and perfumed products or intimate deodorants that alter the flora.
These habits, along with prenatal check-ups, reduce the chances of infection and of silent bacteriuria becoming complicated. The best treatment is the one that isn't needed because it never becomes necessary..
Prenatal check-ups and screening: your safety net
During prenatal checkups, urine is routinely analyzed to detect bacteria, protein, glucose, nitrites, or blood that may not be visible to the naked eye. This screening allows for the early detection of problems before symptoms appear. Taking a culture at the first prenatal visit is a recommended practice and has been shown to reduce the risk of subsequent bacteriuria to less than 1% if the first culture is negative.
Remember to bring a good sample whenever they ask for testing (midstream urine, sterile container). If the result suggests infection, it will be confirmed and the safest treatment plan for the pregnancy will be chosen. Your healthcare team is there to guide you step by step.
When to go to the Emergency Room
In addition to checkups, there are situations that require urgent evaluation: high fever (≥38-39 ºC), intense chills, lower back pain that does not subside (especially on the right side), nausea or vomiting that prevents drinking, worsening after 48 hours of antibiotics, or signs of dehydration. If you notice any of these signs, don't wait..
It is also a reason for priority consultation if you observe persistent blood in the urine, if you cannot urinate normally, or if you notice unusual abdominal contractions or pain associated with urinary symptoms. It's better to rule out in time than to arrive rushed..
Understanding how and why urinary tract infections occur during pregnancy, recognizing the symptoms, knowing when to see a doctor, and adopting simple habits puts you in the best position to avoid unpleasant surprises. With early diagnosis, appropriate antibiotics, and follow-up, UTIs usually resolve without complications for you or the baby.And prenatal checkups, along with good hydration and hygiene, are your best shield throughout pregnancy.
