A 31-year-old woman comes to the emergency depament because of abdominal pain and vaginal spotting. She states that the pain began 2 days ago and has been worsening since. The spotting occurred this morning. Her last menstrual period was 6 weeks ago. She has no medical problems. She takes no medications and has no known drug allergies. Her temperature is 37 C (98.6 F), blood pressure is 90/50 mm Hg, pulse is 110/minute, and respirations are 14/minute. Abdominal examination reveals significant lower abdominal tenderness. Speculum examination shows scant blood in the vagina with a closed cervical os. Bimanual examination demonstrates significant left adnexal tenderness. Urine hCG is positive. Serum hCG is 5,000 mIU/mL. Pelvic ultrasound shows a normal uterus with a left adnexal mass surrounded by free fluid. In MOST cases, the disease process of this patient affects which of the following anatomic structures?
Approximately 98% of the time, ectopic pregnancies are located in the fallopian tube. It is believed that improper transpo of the feilized ovum through the fallopian tube is the most common pathophysiology leading to ectopic pregnancy. Several risk factors are associated with such improper transpo, including pelvic inflammatory disease and prior tubal surgery. Pelvic inflammatory disease and prior tubal surgery result in intraperitoneal scarring and adhesions that can alter the finely tuned transpo mechanisms in the fallopian tubes that are responsible for ensuring that the feilized ovum makes it to the endometrial cavity. Occasionally an ectopic pregnancy can be located in the cervix but this is very uncommon. The cervix is one of the three segments of the uterus (the other two being the body and the fundus). An ectopic pregnancy in this location can be difficult to address surgically. Some ectopic pregnancies are located on or near the ovary. The ovary lies near the fallopian tube in the broad ligament. Ectopic pregnancies on the ovary are also very uncommon. Very rarely an ectopic pregnancy will be located in the peritoneal cavity where it may attach to the surrounding intestines. There are case repos of some of these pregnancies making it to term, although this is extremely rare.
Cervix
Fallopian tube
Ovary
Peritoneal cavity