Differential Diagnosis for Abdominal Pain in a 27-year-old Pregnant Woman
Single Most Likely Diagnosis
- Placental Abruption: This condition is characterized by the premature separation of the placenta from the uterus, which can cause abdominal pain, vaginal bleeding, and fetal distress. The patient's symptoms of sudden onset of constant abdominal pain, vaginal bleeding, and the presence of a tender uterus with frequent contractions support this diagnosis. The fetal heart rate tracing showing occasional late decelerations also suggests fetal distress, which is consistent with placental abruption.
Other Likely Diagnoses
- Preterm Labor: The patient's history of preterm labor and fetal malpresentation in a previous pregnancy, combined with the current symptoms of abdominal pain and frequent uterine contractions, make preterm labor a possible diagnosis. However, the closed cervix on speculum examination makes this less likely.
- Uterine Fibroid Complication: The presence of a 5-cm pedunculated uterine fibroid on ultrasonography could be causing the abdominal pain, especially if the fibroid is degenerating or torsing. However, this would not typically cause vaginal bleeding.
Do Not Miss Diagnoses
- Uterine Rupture: Although less likely, uterine rupture is a life-threatening condition that can occur in pregnant women, especially those with a history of cesarean delivery. The patient's symptoms of severe abdominal pain and tenderness could be indicative of uterine rupture, which requires immediate surgical intervention.
- Ectopic Pregnancy: Although the ultrasonography shows a singleton fetus in the uterus, an ectopic pregnancy cannot be completely ruled out without further evaluation. Ectopic pregnancy is a life-threatening condition that requires prompt diagnosis and treatment.
Rare Diagnoses
- Ovarian Torsion: Ovarian torsion is a rare condition that can cause severe abdominal pain, but it is less likely in this patient given the presence of uterine tenderness and vaginal bleeding.
- Appendicitis: Appendicitis is a rare cause of abdominal pain in pregnant women, especially in the third trimester. However, it is still possible and should be considered in the differential diagnosis, especially if the patient's symptoms do not respond to treatment for other conditions.