Review Question - QID 108567

This patient most likely has trichomonas vaginalis, a parasitic infection that is transmitted through sexual contact. She is most likely at an increased risk for preterm delivery.

Features of this patient’s presentation that suggest trichomonas include watery discharge, which is usually yellow-green and has a foul odor, burning on urination due to urethritis, and the red, punctate lesions on her cervix (“colpitis macularis” or “strawberry cervix”). In a woman presenting with vaginal discharge, cervicitis or vaginitis should be key considerations. For the former, chlamydia and gonorrhea are the most common etiologies and more typically cause purulent discharge. For the latter, trichomonas, bacterial vaginosis (BV), and candidiasis are most likely. Trichomonas is the only sexually transmitted process of the three. Although BV can also present with watery and foul-smelling discharge, it classically has a fish-like odor that enhances when the cervical swab is placed in potassium hydroxide (“amine whiff test”). BV also does not cause inflammation of the vagina or cervix, as trichomonas often does. BV is associated with recent use of antibiotics (as in this patient), which are thought to alter the flora of the vaginal canal. Candidiasis typically presents differently from both BV and trichomonas, with thicker, "cottage cheese" discharge that is odorless. Trichomonas during pregnancy is associated with increased risk of preterm delivery, preterm premature rupture of membranes, and low birth weight.

Figure A shows a strawberry cervix with red punctate lesions and inflammation. This is characteristic of trichomonas.

Incorrect Answers:
Answer 1: Congenital anomalies are not associated with trichomonas infection during pregnancy. Furthermore, this patient is already well into her second trimester. Since most organogenesis occurs within the first 10 weeks of gestation, an infection at this stage of the pregnancy is unlikely to result in a congenital anomaly.

Answer 2: Neonatal sepsis is usually due to group B Streptococcus, Listeria monocytogenes, Escherichia coli, or herpes simplex virus. These organisms are often found in the female reproductive tract and are thus passed to the infant. Trichomonas of the mother is unlikely to infect her child or cause subsequent neonatal sepsis.

Answer 3: Pyelonephritis in pregnancy is usually a result of ascending infection from a lower urinary tract infection due to increased progesterone. This patient complained of burning on urination and has a history of asymptomatic bacteriuria that may predispose her to future UTI or pyelonephritis, in which case she would need another course of antibiotics (for example, nitrofurantoin). However, a UTI or pyelonephritis would not cause vaginal discharge or inflammation, making trichomonas (with urethritis) the more likely diagnosis.

Answer 5: No consequence is a possible outcome of trichomonas in pregnancy, but this patient is at considerable risk for preterm delivery, preterm premature rupture of membranes, and low birth weight.

Bullet Summary:
Trichomonas vaginalis is a sexually transmitted lower reproductive tract infection that should be treated with oral metronidazole for the patient and all sexual partners. In pregnancy, it can increase the risk of preterm delivery, preterm premature rupture of membranes, and low birth weight.