Ectopic Pregnancy

Ectopic pregnancy is the implantation of a fertilized ovum outside the uterine cavity. It most commonly occurs in the fallopian tube, but other sites are possible.

In whites, ectopic pregnancy occurs in about 1 in 200 pregnancies; in nonwhites, in about 1 in 120. The prognosis for the patient is good with prompt diagnosis, appropriate surgical intervention, and control of bleeding; rarely, in cases of abdominal implantation, the fetus may survive to term. Usually, only 1 in 3 women who experience an ectopic pregnancy give birth to a live neonate in a subsequent pregnancy.

Causes

An ectopic pregnancy results from a fertilized egg's inability to work its way quickly enough down the fallopian tube into the uterus. An infection or inflammation of the tube may have partially or entirely blocked it. Pelvic inflammatory disease is the most common of these infections.

Endometriosis or scar tissue from previous abdominal or fallopian surgeries can also cause blockages. More rarely, birth defects or abnormal growths can alter the shape of the tube and disrupt the egg's progress.

Signs and Symptoms

Ectopic pregnancy sometimes produces symptoms of normal pregnancy or no symptoms other than mild abdominal pain (the latter is especially likely in abdominal pregnancy), making diagnosis difficult.

Typically, the patient reports amenorrhea or abnormal menses (after fallopian tube implantation), followed by slight vaginal bleeding and unilateral pelvic pain over the mass.

If the tube ruptures, the patient may complain of sharp lower abdominal pain, possibly radiating to the shoulders and neck. She may indicate that this pain is often precipitated by activities that increase abdominal pressure such as a bowel movement.

During a pelvic examination, the patient may report extreme pain when the cervix is moved and the adnexa is palpated. The uterus feels boggy and is tender.

Diagnostic tests

Serum pregnancy (human chorionic gonadotropin [HCG] test result shows an abnormally low level of HCG and, when repeated in 48 hours, the level remains lower than the levels found in a normal intrauterine pregnancy.

Real-time ultrasonography determines intrauterine pregnancy or ovarian cyst (performed if serum pregnancy test results are positive).

Culdocentesis (aspiration of fluid from the vaginal cul-de-sac) detects free blood in the peritoneum (performed if ultrasonography detects absence of a gestational sac in the uterus).

Laparoscopy may reveal pregnancy outside the uterus (performed if culdocentesis is positive).

Differential diagnosis is used to rule out intrauterine pregnancy, ovarian cyst or tumor, pelvic inflammatory disease (PID), appendicitis, and recent spontaneous abortion.

Treatment

If culdocentesis shows blood in the peritoneum, laparotomy and salpingectomy are indicated, possibly preceded by laparoscopy to remove the affected falopian tube and control bleeding. Patients who wish to have children can undergo microsurgical repair of the fallopian tube. The ovary is saved, if possible; ovarian pregnancy requires oophorectomy. Nonsurgical, management of ectopic pregnancy involves the use of methotrexate, a chemotherapeutic agent, administered istered orally, I.M., or by local infiltration to destroy remaining trophoblastic tissue and avoid the need for lalaparotomy.

Interstitial pregnancy may require hysterectomy; abdominal pregnancy requires a laparotomy to remove the fetus, except in rare cases, when the fetus survives to term or calcifies undetected in the abdominal cavity.

Supportive treatment includes transfusion with whole blood or packed red blood cells to replace excessive blood loss, administration of broad-spectrum I.V. antibiotics for sepsis, administration of supplemental iron (given orally or I.M.), and institution of a high-protein diet.

Prevention

• Avoiding risk factors for pelvic inflammatory disease , such as multiple sexual partners, intercourse without a condom, and sexually transmitted diseases
• Early diagnosis and treatment of STDs
• Early diagnosis and treatment of salpingitis and PID