# Second Trimester Interstitial Ectopic Pregnancy

## TL;DR

A rare case of second trimester interstitial ectopic pregnancy is presented, highlighting diagnostic challenges and the importance of timely recognition.

## Contribution

The paper presents a unique case of an advanced interstitial ectopic pregnancy with atypical imaging findings.

## Key findings

- The gestational sac was located in the interstitial left fallopian tube without rupture.
- Classic imaging signs for ectopic pregnancy were absent due to advanced gestational age and location.
- Timely recognition and management are crucial for interstitial ectopic pregnancies.

## Abstract

Background and Clinical Significance: Interstitial ectopic pregnancy is a rare but potentially life-threatening type of ectopic gestation that carries high risk of rupture and hemorrhage due to its vascular location and predisposition for delayed presentation. Case Presentation: We present a 33-year-old female with acute abdominal pain and elevated β-hCG, with transvaginal ultrasound demonstrating a live left adnexa ectopic pregnancy dated at approximately 14 weeks. MRI confirmed the gestational sac as tubal ectopic, but poorly localized within the interstitial fallopian tube. Exploratory laparoscopy revealed the gestational sac mainly in the interstitial left fallopian tube without rupture or distal involvement. Conclusions: This case demonstrates absent classic imaging findings associated with tubal, interstitial, and ovarian ectopic gestations including tubal ring sign, interstitial line sign, endo-myometrial mantle measurement, or claw sign due to location and advanced gestational age. Familiarity with these challenges and recognition that interstitial ectopic pregnancy may present atypically are important for timely recognition and management.