Ectopic pregnancy is the implantation of a fertilized ovum outside the endometrial cavity. It is a rapidly progressing medical emergency requiring early recognition and intervention to prevent morbidity and mortality. Ruptured ectopic pregnancy is the number one cause of mortality in pregnancy-related deaths in the first trimester. Despite advancements in the diagnosis of ectopic pregnancy, it remains a serious source of maternal mortality, especially in developing countries due to limited healthcare. The incidence for ectopic pregnancy in females from 15 to 45 years old is 1 in 100 females in the general population, while those with preexisting tubal disease are more susceptible. Although several risk factors increase the likelihood of patients having ectopic pregnancy, nearly one-third of ectopic pregnancies have no identifiable risk factors (Table 162-1).
TABLE 162-1Risk Factors for Ectopic Pregnancy |Favorite Table|Download (.pdf) TABLE 162-1 Risk Factors for Ectopic Pregnancy
Prior ectopic pregnancy
Prior tubal surgery
Pelvic inflammatory disease
Congenital anatomic distortion, e.g., exposure to diethylstilbestrol
Use of intrauterine device
History of infertility
Lifestyle choices, i.e., smoking, vaginal douching
Assisted reproductive technology
Ruptured ectopic pregnancy most commonly involves trophoblastic proliferation extending into surrounding blood vessels. It first invades the luminal mucosa, then muscularis, followed by lamina propria and the serosa. Invasion into the large blood vessels of the broad ligament predisposes patients to life-threatening hemorrhage and painful distortion of the tube.
It is important to recognize a fertilized ovum can implant anywhere on the path of migration or the abdominal cavity (Figure 162-1). Most ectopic pregnancies are tubal, implanting on the infundibulum, fimbriae, ampulla, or isthmus. Roughly, 2% of ectopic pregnancies are localized at the cervix, vagina, ovary, or abdominal cavity.
Location of ectopic pregnancy. (Reproduced with permission from Benson RC. Benson & Pernoll’s Handbook of Obstetrics & Gynecology, 9th ed. New York, NY: McGraw-Hill Education, Inc; 1994.)
Ectopic pregnancy patients may present in a variety of ways, depending on their gestational age, implantation site, and the presence of active hemorrhage. Early diagnosis and detection will provide the most significant improvement in morbidity and mortality. Patients often present with lower quadrant pain, vaginal bleeding, delayed menses, increases in serum beta-human chorionic gonadotropin (β-HCG), and shoulder pain from subdiaphragmatic intraperitoneal blood.
Pain is often the first symptom of ectopic pregnancy. This symptom is followed by vaginal bleeding which is typically caused by the breakdown of the decidual lining of the uterine wall. The lining is likely compromised due to decreased HCG production by the ectopic trophoblast and insufficient hormone production by the corpus luteum. Patients may also present with dizziness, syncope, and orthostatic hypotension due to massive blood loss. It ...