Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases

Ectopic Pregnancy

An ectopic pregnancy occurs when a fertilized ovum implants outside the uterine cavity, most commonly in the fallopian tube. Prognosis is good with prompt diagnosis, appropriate surgical intervention, and control of bleeding. Few ectopic pregnancies are carried to term; rarely, with abdominal implantation, the fetus survives to term.

In whites, ectopic pregnancy occurs in about 1 of 200 pregnancies. In non-whites, the incidence is about 1 of 120 pregnancies.

Causes

·   Endosalpingitis

·   Diverticula

·   Tumors pressing against the tube

·   Previous surgery, such as tubal ligation or resection

·   Transmigration of the ovum

·   Congenital defects in reproductive tract

·   Ectopic endometrial implants in the tubal mucosa

·   Sexually transmitted tubal infection

·   Intrauterine device

Pathophysiology

In ectopic pregnancy, transport of a blastocyst to the uterus is delayed and the blastocyst implants at another available vascularized site, usually the fallopian tube lining. Normal signs of pregnancy are initially present and uterine enlargement occurs in about 25% of cases. Human chorionic gonadotropin (HCG) hormonal levels are lower than in uterine pregnancies. If the ectopic pregnancy isn't interrupted, internal hemorrhage occurs with rupture of the fallopian tube.

Signs and symptoms

·   Abdominal tenderness and discomfort

·   Amenorrhea

·   Abnormal menses (after fallopian tube implantation)

·   Slight vaginal bleeding

·   Unilateral pelvic pain over the mass

·   If fallopian tube ruptures, sharp lower abdominal pain, possibly radiating to the shoulders and neck

Clinical Tip

Ectopic pregnancy sometimes produces symptoms of normal pregnancy or no symptoms other than mild abdominal pain (especially in abdominal pregnancy).

·   Possible extreme pain when cervix is moved and adnexa palpated

·   Boggy and tender uterus

·   Adnexa may be enlarged

Diagnostic tests

·   Blood test reveals abnormally low serum HCG; when repeated in 48 hours, level remains lower than levels found in a normal intrauterine pregnancy.

·   Real-time ultrasonography shows intrauterine pregnancy or ovarian cyst.

·   Culdocentesis shows free blood in the peritoneum.

·   Laparoscopy reveals pregnancy outside the uterus.

Treatment

·   Transfusion with whole blood or packed red blood cells

·   Broad-spectrum I.V. antibiotics

·   Supplemental iron

·   Methotrexate

·   Analgesics

·   RhO immune globulin if the patient is Rh negative

·   Laparotomy and salpingectomy if culdocentesis shows blood in the peritoneum; possibly after laparoscopy to remove affected fallopian tube and control bleeding

·   Microsurgical repair of the fallopian tube for patients who wish to have children

·   Oophorectomy for ovarian pregnancy

·   Hysterectomy for interstitial pregnancy

·   Laparotomy to remove the fetus for abdominal pregnancy

P.313

ECTOPIC PREGNANCY

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