What is the diagnosis for a 34-year-old woman presenting with contractions, rupture of membranes (ROM), and vaginal bleeding, with a temperature of normothermia, blood pressure of normotension, and tachycardia, and fetal heart rate (FHR) tracing showing a baseline of 150 beats per minute (bpm) with absent baseline variability?

Differential Diagnosis for a 34-year-old Woman in Labor

• Single most likely diagnosis:
  • Normal Labor: The patient's presentation with contractions, rupture of membranes, and progressive cervical dilation is consistent with normal labor. The absence of baseline variability in the fetal heart rate tracing can be seen in a normal fetus, especially if the fetus is sleeping. The use of morphine for pain relief could also contribute to decreased fetal movement and variability.
• Other Likely diagnoses:
  • Opioid-induced Fetal Depression: The multiple doses of morphine administered for pain relief could be causing fetal depression, leading to the absent baseline variability and lack of accelerations in the fetal heart rate tracing.
  • Fetal Distress due to Occiput Posterior Position: The occiput posterior position can cause fetal distress due to increased pressure on the fetal head and spine, potentially leading to changes in the fetal heart rate tracing.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Umbilical Cord Prolapse: Although the membranes are ruptured and the fluid is clear, umbilical cord prolapse is a life-threatening emergency that must be considered, especially if there are concerns about fetal well-being.
  • Placental Abruption: The presence of vaginal bleeding and a non-reassuring fetal heart rate tracing raises the concern for placental abruption, which is a serious condition requiring prompt intervention.
  • Uterine Rupture: Although less likely, uterine rupture is a catastrophic event that can occur in labor, especially in women with a history of previous uterine surgery or other risk factors.
• Rare diagnoses:
  • Amniotic Fluid Embolism: This is a rare but potentially life-threatening condition that can occur during labor, especially with rupture of membranes and vaginal bleeding.
  • Fetal Anomaly or Congenital Infection: Although less likely, the absence of baseline variability and lack of accelerations in the fetal heart rate tracing could be indicative of a fetal anomaly or congenital infection.