Chapter 127 Ectopic Pregnancy
INTRODUCTION
Description: An ectopic pregnancy is one that implants outside of the endometrial cavity (fallopian tube, ovary, abdominal cavity, or cervix).
Prevalence: Ten to 15 of 1000 pregnancies; varies with age, race, and location (highest in Jamaica and Vietnam).
ETIOLOGY AND PATHOGENESIS
Causes: Tubal damage or altered motility that causes the fertilized egg to be improperly transported, resulting in implantation outside the uterine cavity. The most common cause is acute salpingitis (50%). In the majority of the remaining patients (40%), no risk factor is apparent. Abnormal embryonic development may play a role.
Risk Factors: Tubal damage (pelvic infections; 6-fold increased risk), prior ectopic pregnancy (10-fold increased risk), prior female sterilization, age (age 35 to 44, 3-fold greater rate of extrauterine gestations than for women aged 15 to 24), nonwhite race (1.5-fold increased risk), assisted reproduction, cigarette smoking (30+/day: 3- to 5-fold increased risk), intrauterine contraceptive device (IUCD) use, and endometriosis. More than half of cases occur in women who have been pregnant three or more times.
