Differential Diagnosis for Vaginal Pain in the First Trimester

Single Most Likely Diagnosis

• Threatened abortion or miscarriage: This is a common cause of vaginal pain in the first trimester, often accompanied by bleeding. The pain can range from mild to severe and is usually associated with a potential or actual miscarriage.

Other Likely Diagnoses

• Implantation cramping: Mild cramping can occur as the embryo implants into the uterine lining, typically around 6-10 days after fertilization.
• Round ligament pain: As the uterus expands, the round ligaments stretch, causing pain that can be sharp and stabbing, often on one side.
• Urinary tract infection (UTI): UTIs can cause dysuria, frequency, and suprapubic pain, which might be mistaken for vaginal pain.
• Vaginal infections: Yeast infections, bacterial vaginosis, or trichomoniasis can cause vaginal discomfort, itching, and pain.

Do Not Miss Diagnoses

• Ectopic pregnancy: Although less common, ectopic pregnancy is a life-threatening condition that can present with vaginal pain, often accompanied by abdominal pain and bleeding. It requires immediate medical attention.
• Ovarian torsion: This is a rare but emergency condition where the ovary twists, cutting off its blood supply. It can cause severe, sudden pain and requires immediate surgical intervention.

Rare Diagnoses

• Müllerian duct anomalies: Abnormalities in the development of the female reproductive tract can cause various symptoms, including pain, but are less common.
• Vaginal cysts or tumors: These can cause localized pain and are relatively rare.
• Endometriosis: While more commonly associated with chronic pelvic pain, endometriosis can cause pain during the first trimester, especially if there are implants in the vagina or on the cervix.