Bacterial Vaginosis

Patient Presentation:
SD, an 18 year old teenager came to the labor and delivery unit complaining of preterm contractions that had started three days prior to arrival. She was 26 weeks pregnant, and it was her first pregnancy. She had a history of genital herpes and asthma. She was taking albuterol as needed for her asthma. Her vital signs were HR 87; BP 126/72; T 37.2 degrees Celsius; SaO2 99% on room air. When the patient was placed on the external fetal monitor, the tocometer (contraction monitor) showed that the patient was contracting every 2 to 3 minutes. When the resident put the patient in lithotomy position to perform a speculum exam to see if her cervix was dilated, a fishy smell permeated the room. The resident noticed homogeneous, thin, grayish-white discharge that smoothly coated the vaginal walls. When questioned, the patient stated that she had been having an increase in thin, off-white discharge for the past three months. She had assumed it was a normal sign of pregnancy. The patient did not feel any of the contractions that were showing up on the external fetal monitor.

Differential Diagnosis:

Diagnosis:
The resident took a sample of the discharge and placed it on the glass side to examine it under the microscope.  Clue cells were noted on the saline wet mount. The patient’s cervix was long and closed which ruled out preterm labor. The patient denied vaginal itching, and the discharge did not look like yeast. A positive whiff test helped confirm the diagnosis of BV

Treatment/Prognosis:
Once the diagnosis was made, the patient was given a prescription for metronidazole 250 mg orally three times daily for seven days. IV fluids had been started because of the contractions. She stopped contracting after a 1000ml bolus of lactated ringers. Approximately 30 percent of patients with initial responses to therapy have a recurrence of symptoms within three months and more than 50 percent experience a recurrence within 12 months

Outcome:
The patient was sent home with her prescription later that day.  Her physician saw her in the office three weeks later. Her bacterial vaginosis had resolved. She returned to the labor and delivery unit 14 weeks later and delivered a 7 lb 4 ounce baby girl.

Case created by Sarah Davis, 2011.