Differential Diagnosis for a 34-year-old Pregnant Female with Right-Sided Pain Radiating to the Groin and Leg

The patient presents with pain on her right side that radiates down her leg to the groin, accompanied by nausea, and a recent confirmation of pregnancy. Given these symptoms, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Ovarian Cyst or Torsion: This condition is a common cause of acute pelvic pain, especially in pregnant women. The pain can radiate to the groin and leg due to the location of the ovaries and their potential to twist, cutting off their blood supply. Pregnancy increases the risk of ovarian torsion due to the displacement of pelvic organs.

• Other Likely Diagnoses

  • Appendicitis: Although the pain of appendicitis typically starts near the navel and then moves to the lower right abdomen, it can sometimes present with pain radiating to the groin. Pregnancy can alter the typical presentation of appendicitis due to the displacement of the appendix by the growing uterus.
  • Urinary Tract Infection (UTI) or Pyelonephritis: These conditions can cause flank pain that radiates to the groin, accompanied by nausea and vomiting. Pregnancy increases the risk of UTIs due to physiological changes in the urinary tract.
  • Round Ligament Pain: As the uterus expands during pregnancy, the round ligaments that support it can stretch, causing pain on either side of the abdomen that can radiate to the groin.

• Do Not Miss Diagnoses

  • Ectopic Pregnancy: Although the patient denies vaginal bleeding, ectopic pregnancy is a life-threatening condition that must be considered in any pregnant woman with abdominal or pelvic pain. The pain can be unilateral and severe, and it may radiate to the groin.
  • Pulmonary Embolism: Pregnancy increases the risk of blood clots and pulmonary embolism. While the primary symptom is usually shortness of breath, chest pain, or cough, in some cases, the pain can be referred to the abdomen or groin due to the involvement of the diaphragm or other mechanisms.
  • Ruptured Aneurysm or Arteriovenous Malformation: These vascular emergencies can cause severe, acute pain and are life-threatening. They might not be the first consideration but should be kept in mind, especially if the patient has a history of vascular disease.

• Rare Diagnoses

  • Adnexal Tumor: Although less common, adnexal tumors can cause pain due to torsion, rupture, or other complications. They might be considered if other diagnoses are ruled out and the pain persists or worsens.
  • Inguinal Hernia: Pregnancy can increase intra-abdominal pressure, potentially leading to the formation or exacerbation of an inguinal hernia, which could cause groin pain. However, this would be less common in the context of the other symptoms described.