Ectopic Pregnancy Risk Factors
The correct answer is B: A history of pelvic inflammatory disease (PID) significantly increases the risk of ectopic pregnancy. 1
Why Option B is Correct
Salpingitis (pelvic inflammatory disease) with resulting tubal occlusion doubles the likelihood of ectopic pregnancy with each recurrent episode. 1 This makes PID one of the most important risk factors for ectopic pregnancy, as it causes tubal damage and altered embryo transport—the primary mechanism underlying most ectopic pregnancies. 1
Key Risk Factors for Ectopic Pregnancy
The evidence clearly establishes a hierarchy of risk factors:
- History of tubal surgery (including sterilization) carries the highest risk 1
- Pelvic inflammatory disease/salpingitis doubles risk with each recurrent episode 1
- Previous ectopic pregnancy results in significant risk increase 1
- Chlamydia trachomatis infection (a common cause of PID) 2
- Cigarette smoking 3, 2, 4
- Infertility and assisted reproduction 3, 4
- Age over 35 years 5
All identified risk factors are maternal and relate primarily to tubal damage and altered embryo transport. 2
Why the Other Options are Incorrect
Option A: "Also known as spontaneous abortion"
This is completely incorrect. Ectopic pregnancy is a pregnancy implanting outside the uterine cavity (most commonly in the fallopian tube), while spontaneous abortion is a pregnancy loss occurring within the uterus. 3, 6 These are entirely different conditions with different pathophysiology and management.
Option C: "Rarely noticed by women"
This is false. The classic symptoms of ectopic pregnancy are secondary amenorrhea, abdominal pain, and vaginal bleeding. 6 Ectopic pregnancy should be considered in any patient presenting early in pregnancy with vaginal bleeding or lower abdominal pain. 3, 5 While symptoms vary in acuteness, the condition is typically symptomatic and noticed by patients.
Option D: "The same thing as a molar pregnancy"
This is incorrect. Molar pregnancy (gestational trophoblastic disease) is an abnormal intrauterine pregnancy with abnormal placental tissue development, completely distinct from ectopic pregnancy which involves extrauterine implantation. 3
Clinical Significance
Ectopic pregnancy remains the most common cause of maternal death and serious morbidity in the first trimester of pregnancy, accounting for 9% of pregnancy-related maternal deaths. 1 Understanding risk factors, particularly the strong association with PID, is essential for early diagnosis and prevention of life-threatening complications. 1, 5
A significant number of patients with confirmed ectopic pregnancy will not have an identifiable risk factor, 5 so clinicians must maintain high suspicion even in the absence of classic risk factors.