Differential Diagnosis for Subtle Right Lower Abdominal Pain in an 11-Week Pregnant Woman

• Single Most Likely Diagnosis
  • Constipation: Given the patient's reported constipation, it is likely that the subtle right lower abdominal pain is related to constipation, which is a common issue during pregnancy due to hormonal changes and pressure from the expanding uterus.
• Other Likely Diagnoses
  • Ovarian cyst complication (e.g., torsion, rupture): Although the presence of a 2-3 cm hemorrhagic ovarian cyst could be incidental, there is a risk of complications such as torsion or rupture, which could cause abdominal pain.
  • Urinary tract infection (UTI): UTIs are common during pregnancy and can cause abdominal pain, although the pain is typically more pronounced and accompanied by other symptoms like dysuria and frequency.
• Do Not Miss Diagnoses
  • Ectopic pregnancy: Although the patient is 11 weeks pregnant and an ectopic pregnancy would be unusual at this gestational age, it is a life-threatening condition that must be considered, especially if there is any suspicion of a ruptured ectopic pregnancy.
  • Appendicitis: Appendicitis can occur during pregnancy and may present with atypical symptoms, making it crucial to consider this diagnosis to avoid missing a potentially life-threatening condition.
  • Placental abruption: This condition, where the placenta separates from the uterus, can cause abdominal pain and is a medical emergency.
• Rare Diagnoses
  • Ovarian tumor: Although rare, ovarian tumors can cause abdominal pain and should be considered, especially if the ovarian cyst is large or shows suspicious features on imaging.
  • Renal colic: Kidney stones can cause severe abdominal pain and should be considered, especially if the patient has a history of kidney stones or if the pain is severe and radiates to the groin.