A 24 yo female presents with 3 days of worsening right lower quadrant pain.
The pain is sharp, severe, worse with movement. The patient has no fever, nausea or vomiting and scant vaginal bleeding. The patient states that her last menstrual period came one month ago at its normal time but only lasted 2 days (short for her). Her pregnancy test is currently positive.
Where is the pregnancy?
This is a large (12week) right adnexal ectopic pregnancy. The uterus is in the center of the screen (still image 1) and ones eyes should focus on the hyperechoic endometrium that has no sac inside it. The right adnexal ectopic is large and could easily be mistaken as intrauterine (still image 2). In any first trimester OB scan, the first step is to identify the uterus, and then determine if the gestation is within the uterine cavity. Large ectopic pregnancies can be mistaken for intrauterine because the walls are thick and the fetus is distracting.
Is this a ruptured ectopic pregnancy?
No, at the time of presentation the ectopic was unruptured. There is no free fluid in the Pouch of Douglas or surrounding the ectopic. In general, free fluid is black and tracks between tissue planes creating a "pointy" pocket of free fluid. Clotted blood however, can appear gray and can be mistaken for bowel and fat.