Urinary and Vaginal Infections in Pregnancy

Three treatments at once, and what I’d ask from the first visit

What I learned about urinary tract infections, bacterial vaginosis and yeast in pregnancy: how they’re tested and treated, why they come back and how to talk to your provider.

Key points

The U.S. Preventive Services Task Force recommends a urine culture at the first prenatal visit or at 12 to 16 weeks, whichever is earlier, even without symptoms. Treating significant bacteria found this way can lower the risk of a kidney infection. Ask whether your culture has been done.
A negative dipstick does not reliably rule out a urinary infection in pregnancy. A 2016 review of screening for bacteria in urine without symptoms found that the nitrite part of the dipstick detected about 55% of cases. If you have symptoms, ask your clinician about a urine culture.
In pregnancy, the CDC recommends only topical yeast treatment, for 7 days, and says oral fluconazole, a yeast pill, shouldn’t be used. Check with your provider before using any yeast treatment, including over the counter.

What happened to me

In my first pregnancy, I wrote to my practice for months about the same cluster of symptoms: discharge, spotting, urinary pain, yeast and bacterial vaginosis. Around eight weeks, I noticed debris in my urine and pain near my kidneys. I lived outside the city, so I was told to get checked locally, and urgent care started me on an antibiotic. After that course, a later result showed the bacteria had increased again.

By late pregnancy, my chart listed it all: “GBS bacteriuria, symptomatic bacteriuria (on suppression), asthma, recurrent BV and yeast (on suppression).” My doctor laid out the regimen in one message: “Nitrofurantoin 100 mg capsule daily for urinary tract infection suppression,” “Metrogel 0.75% gel 2 DAYS PER WEEK of your choosing for BV suppression,” and “MICONAZOLE – 2 DAYS PER WEEK of your choosing for yeast suppression.”

I asked what finding justified each prescription and what suppression meant. At one point, I wrote: “I’d love to better understand what specific symptoms I need to look out for to warrant metronidazole and miconozole?” My doctor answered, in long messages, and offered to talk through suppression by phone. What I didn’t have was a picture of the whole thing: why it kept coming back, how we’d know the treatment was working and when it would end. For the last two months of my pregnancy, I was on three treatments at once.

In my second pregnancy, it started again: pressure, urgency and pain. An ER dipstick test came back negative. A later culture grew E. coli. I asked for an exam, a swab taken by a clinician, repeat testing and an explanation of whether the antibiotic matched the culture report. My OB scheduled a follow-up urine test after that first infection, without my asking, to make sure it had cleared.

Urinary tract infections

How common. Bacteria in the urine without symptoms show up in 2% to 10% of pregnancies. Urinary tract infections affect about 8% and are linked to preterm delivery and low birth weight.

How it’s tested. A urine culture checks for bacteria and can help identify an antibiotic that will work. A dipstick is quicker, but its nitrite result alone is not a reliable rule-out test. In a 2016 review of asymptomatic screening tests in pregnancy, pooled nitrite sensitivity was 55%. That is not the same as the accuracy of the full dipstick in someone with symptoms.

Why it matters. In the Task Force’s review, treating bacteria found without symptoms was linked to a 76% relative reduction in kidney infections. Most trials were old, and untreated patients in more recent studies had a lower starting risk. Evidence for reducing low birth weight was less certain.

When it keeps coming back. Two or more UTIs in one pregnancy counts as recurrent and happens in 4% to 5% of pregnancies. A daily low-dose antibiotic, called suppression, may be considered. The evidence is thin: a Cochrane review of the research found one trial of 200 women, where daily nitrofurantoin didn’t reduce repeat kidney infections, and rated the evidence very low quality.

Near the end of pregnancy. Nitrofurantoin (Macrobid) is generally avoided at term because of a risk of anemia in the newborn. That’s why, in my first pregnancy, my antibiotic was switched at 36 weeks.

Testing after treatment. After treatment for bacteria found without symptoms, the American College of Obstetricians and Gynecologists (ACOG) found insufficient evidence for routinely repeating the culture. If symptoms persist after treatment for a bladder infection, a repeat culture is the next step. Some clinicians repeat it either way, depending on your history. Ask what your plan is.

Group B strep in the urine. GBS in the urine at any point in pregnancy usually means antibiotics are needed during labor, without the routine late-pregnancy GBS swab. The exception is a cesarean performed before labor begins while the membranes are still intact. Antibiotics given for the surgery itself are a separate matter. Ask your team to record your plan.

Bacterial vaginosis

How common. BV affects an estimated 5.8% to 19.3% of pregnant women in the U.S., and is associated with preterm delivery. The Task Force recommends against screening pregnant women at low risk of preterm birth who don’t have symptoms.

Treatment. The CDC recommends treating everyone pregnant who has symptoms, and says metronidazole has shown no evidence of causing birth defects.

Recurrence. After treatment with oral metronidazole, BV came back in 58% of women within 12 months. Twice-weekly metronidazole gel for more than three months reduces recurrence, according to the CDC, but the benefit ends when you stop.

Yeast

Treatment in pregnancy. The CDC recommends only topical azole (antifungal) creams or suppositories for 7 days. Oral fluconazole shouldn’t be used. In a Danish study, fluconazole in early pregnancy was associated with a higher risk of miscarriage.

How often to test

First prenatal visit, or 12 to 16 weeks: A urine culture, even without symptoms
Any time you have symptoms: A culture, not just a dipstick, and a swab if there’s discharge
After treatment: Whether a repeat culture is planned, or what to do if symptoms return
36 to 37 weeks: The GBS swab, unless GBS has already shown up in your urine
On suppression: The plan for how long, and what would show it’s working

How I talk to my provider about it

I ask for the working explanation, not just a prescription: what do they think is going on, and what would change their mind?
I ask whether the antibiotic matches the culture. In my second pregnancy, I asked for the culture and the match.
I bring the actual results, printed or saved, including the susceptibility report.
I keep a one-page symptom log, one line per episode: when it started, what it felt like, what was tested, what was prescribed and whether it worked. In my first pregnancy, my portal messages were the only record of the pattern.

Take this back

To discuss with your care team:

Has my urine culture been done, and what did it show?
What do you think is causing this, and what would change that?
Does this antibiotic match what grew?
Will you repeat the culture after treatment?
If I’m on suppression, how will we know it’s working, and when do we stop?
If symptoms come back, do I call, come in or get a culture first?
Should I see a specialist if this keeps recurring?

To discuss with the people in your life: If I say “it’s back,” will you help me make the call that day?

Don’t wait if

Fever, chills, vomiting or pain in the back or side, along with urinary symptoms, can signal a kidney infection. A fever of 100.4°F or higher is an urgent maternal warning sign. Seek medical care immediately. If you can’t reach your care team, go to the emergency department. Tell them you’re pregnant and list your medications.

Next in the series: “Preeclampsia: Know the Numbers”