What is the diagnosis for a 30-year-old woman, gravida (number of times pregnant) 3, para (number of viable births) 1, aborta (number of spontaneous abortions) 1, at 26 weeks gestation, presenting with increased vaginal discharge, spotting, and a history of positive urine culture, with normal vital signs, a soft and nontender abdomen, and an amniotic fluid index of 3 cm?

Differential Diagnosis for Increased Vaginal Discharge and Spotting in a 26-Week Pregnant Woman

• Single most likely diagnosis:
  • Premature rupture of membranes (PROM): The presence of clear, nitrazine-positive fluid in the vagina, which is indicative of amniotic fluid, strongly suggests PROM. The patient's symptoms of increased vaginal discharge and spotting also support this diagnosis.
• Other Likely diagnoses:
  • Urinary tract infection (UTI): Although the patient has a positive urine culture, she has not started antibiotics and may be experiencing symptoms related to the infection, such as increased discharge. However, the presence of nitrazine-positive fluid suggests that PROM is more likely.
  • Cervical inflammation or infection: The patient's increased discharge and spotting could be related to cervical inflammation or infection, but the absence of other symptoms such as fever or cervical tenderness makes this less likely.
• Do Not Miss diagnoses:
  • Placental abruption: Although the patient's ultrasound shows an anterior placenta, placental abruption is a life-threatening condition that can cause vaginal bleeding and should be considered, especially if the patient's symptoms worsen or if there are concerns about fetal well-being.
  • Uterine rupture: Given the patient's history of a previous cesarean delivery, uterine rupture is a rare but potentially life-threatening complication that should be considered, especially if the patient experiences severe abdominal pain or vaginal bleeding.
• Rare diagnoses:
  • Amniotic fluid embolism: This is a rare but potentially life-threatening condition that can occur when amniotic fluid enters the maternal circulation. Although the patient's symptoms do not currently suggest this diagnosis, it should be considered if her condition worsens or if there are concerns about fetal well-being.
  • Chorioamnionitis: This is an infection of the amniotic fluid and placenta that can cause increased vaginal discharge, fever, and other symptoms. Although the patient does not currently have a fever, this diagnosis should be considered if her symptoms worsen or if there are concerns about fetal well-being.