A 25 year old woman complains of abdominal pain of rapid onset in the right lower quadrant. She subsequently undergoes surgery for suspected acute appendicitis. At surgery, however, a tubal pregnancy is discovered. The most frequent predisposing factor for this condition is?
The great majority of ectopic pregnancies (90%) occur in the fallopian tubes. The other sites are the ovaries, abdominal cavity, and the intrauterine segment of the fallopian tubes. Any condition that leads to anatomical abnormalities of the uterus and fallopian tubes may predispose to ectopic pregnancy. The most frequent of such conditions is pelvic inflammatory disease (PID), which is usually associated with salpingitis. PID is a common infectious condition most frequently caused by Neisseria gonorrhoeae and Chlamydia trachomatis, both sexually transmitted. Other cases are due to a polymicrobial population, including staphylococci, streptococci, coliform bacteria, and Clostridium perfringens, acquired during aboion or delivery. PID leads to acute purulent salpingitis. If this is untreated or inadequately treated, it progresses to salpingo-oophoritis, tubal abscesses, pyosalpinx, or hydrosalpinx. Even milder cases may cause adhesions within the tube or between the tube and the ovary that interfere with implantation of the ovum and result in tubal pregnancy. All the remaining conditions listed above may also predispose to ectopic pregnancy. Endometriosis refers to the presence of endometrium in abnormal locations, such as the ovary, uterine ligaments, rectovaginal pouch, and pelvic peritoneum. It is an impoant clinical condition manifesting with pain, dysmenorrhea, and infeility. Scarring at endometriotic sites may cause peritubal adhesions and ectopic pregnancy. An intrauterine device may also increase the risk of ectopic pregnancy, but the mechanism of action is not clear. Leiomyomas of the uterus are the most frequent benign tumor in women. They develop from the smooth muscle as well-circumscribed nodules within the uterine wall (intramural), in a subserosal or submucosal location. Leiomyomas may cause significant distoion of the uterine wall and interfere with implantation, increasing the risk of ectopic pregnancy. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 10. Ectopic Pregnancy. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.
Endometriosis
A an intrauterine device
Leiomyomas of the uterus
Pelvic inflammatory disease