Definition. This is a pregnancy in which implantation has occurred outside of the uterine cavity. The most common location of ectopic pregnancies is an oviduct. The most common location within the oviduct is the distal ampulla. Differential Diagnosis. With a positive pregnancy test, the differential diagnosis consists of a threatened abortion, incomplete abortion, ectopic pregnancy, and hydatidiform mole. In a reproductive age woman with abnormal vaginal bleeding, the possibility of pregnancy or complication of pregnancy should always be considered. Risk Factors. The most common predisposing cause is previous pelvic inflammatory disease (PID). Ectopic pregnancy risk is increased from any obstruction of normal zygote migration to the uterine cavity from tubal scarring or adhesions from any origin: infectious (PID, IUD), postsurgical (tubal ligation, tubal surgery), or congenital (diethylstilbestrol [DES] exposure). One percent of pregnancies are ectopic pregnancies, and if the patient has had one ectopic pregnancy, the incidence becomes 15%. Clinical Findings • Symptoms. The classic triad with an unruptured ectopic pregnancy is amenorrhea, vaginal bleeding, and unilateral pelvic-abdominal pain. With a ruptured ectopic preg- nancy, the symptoms will vary with the extent of intraperitoneal bleeding and irritation. Pain usually occurs after 6–8 menstrual weeks. • Signs. The classic findings with an unruptured ectopic pregnancy are unilateral adnexal and cervical motion tenderness. Uterine enlargement and fever are usually absent. With a ruptured ectopic pregnancy, the findings reflect peritoneal irritation and the degree of hypovolemia. Hypotension and tachycardia indicate significant blood loss. This results in abdominal guarding and rigidity. • Investigative findings. A β-hCG test will be positive. Sonography may or may not reveal an adnexal mass, but most significantly no intrauterine pregnancy (IUP) will be seen.
