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In
ectopic pregnancy, implantation occurs in a site other than the
endometrial lining of the uterine cavity—in the fallopian tube, uterine
interstitium, cervix, ovary, or abdominal or pelvic cavity.
Ectopic pregnancies cannot be carried to term and eventually rupture
or involute. Early symptoms and signs include pelvic pain, vaginal bleeding,
and cervical motion tenderness. Syncope or hemorrhagic shock can
occur with rupture. Diagnosis is by β-human
chorionic gonadotropin measurement and ultrasonography.
Treatment is with laparoscopic or open surgical resection or with
IM methotrexate.
Incidence of ectopic pregnancy (overall, 2/100 diagnosed pregnancies) increases as maternal age increases. Other risk factors include prior pelvic inflammatory disease (particularly due to Chlamydia
trachomatis), prior tubal surgery, prior ectopic pregnancy (10 to 25% recurrence risk), cigarette smoking, exposure to diethylstilbestrol, and prior induced abortion. Pregnancy is less likely to occur when an intrauterine device (IUD) is in place; however, about 5% of such pregnancies are ectopic. Simultaneous ectopic and intrauterine pregnancies occur in only 1/10,000 to 30,000 pregnancies but may be more common among women who have undergone ovulation induction or assisted reproductive techniques such as in vitro fertilization and gamete intrafallopian tube transfer (GIFT); in such cases, the reported ectopic pregnancy rate is ≤ 1%.
The most common site of ectopic implantation is a fallopian tube, followed by the uterine interstitium (cornua). Cervical, cesarean section scar, ovarian, abdominal, and pelvic pregnancies are rare. Rupture of an ectopic pregnancy results in bleeding that can be gradual, or rapid enough to produce hemorrhagic shock. Intraperitoneal blood eventually causes peritonitis.
Symptoms and Signs
Symptoms vary. Most patients have pelvic pain, sometimes crampy, vaginal bleeding, or both. Menses may or may not be delayed or missed. Rupture may be heralded by sudden, severe pain, followed by syncope or by symptoms and signs of hemorrhagic shock or peritonitis. Rapid hemorrhage is more likely in cornual ectopic pregnancies.
Cervical motion tenderness, unilateral or bilateral adnexal tenderness, or an adnexal mass may be present. The uterus may be slightly enlarged (but less than anticipated based on date of last menstrual period).
Diagnosis
Ectopic pregnancy is suspected in any female of reproductive age with pelvic pain, vaginal bleeding or unexplained syncope or hemorrhagic shock, regardless of sexual, contraceptive, and menstrual history. Findings of physical (including pelvic) examination are neither sensitive nor specific. Diagnosis requires measurement of the urine β subunit of human chorionic gonadotropin (β-hCG), which is about 99% sensitive for pregnancy (ectopic and otherwise). If urine β-hCG is negative and if clinical findings do not strongly suggest ectopic pregnancy, further evaluation is unnecessary unless symptoms recur or worsen. If urine β-hCG is positive or if clinical findings strongly suggest ectopic pregnancy, quantitative serum β-hCG and pelvic ultrasonography are indicated. If quantitative serum β-hCG is < 5 mIU/mL, ectopic pregnancy is excluded. If ultrasonography detects an intrauterine gestational sac, ectopic pregnancy is extremely unlikely except in women who have used assisted reproductive technologies; however, cornual and intraabdominal pregnancies may appear similar to intrauterine pregnancies. Ultrasonographic findings suggesting ectopic pregnancy (noted in 16 to 32%) include complex (mixed solid and cystic) masses, particularly in the adnexa; free fluid in the cul-de-sac; and absence of a uterine gestational sac on transvaginal views, particularly if the β-hCG level is > 1000 to 2000 mIU/mL. Absence of an intrauterine sac with a β-hCG level > 2000 mIU/mL strongly suggests an ectopic pregnancy. Use of transvaginal and color Doppler ultrasonography may improve detection rates.
If ectopic pregnancy appears unlikely and patients are stable, serum levels of β-hCG can be measured serially on an outpatient basis. Normally, the level doubles every 1.4 to 2.1 days up to 41 days; in ectopic pregnancy (and in abortions), levels may be lower than expected by dates and usually do not double as rapidly. If initial evaluation or serial β-hCG levels suggest ectopic pregnancy, diagnostic laparoscopy may be necessary for confirmation. Progesterone levels may be measured when the diagnosis is unclear; if they are ≤ 5 ng/mL, a viable intrauterine pregnancy is very unlikely.
Prognosis
and Treatment
Untreated ectopic pregnancy is fatal to the fetus, but if treatment occurs before rupture, maternal death is very rare. In the US, ectopic pregnancy probably accounts for 9% of pregnancy-related maternal deaths.
Hemorrhagic shock is treated (see Shock and Fluid Resuscitation: Prognosis and Treatment); such hemodynamically unstable patients require immediate laparotomy. For stable patients, treatment is usually laparoscopic surgery; sometimes laparotomy is required. If possible, salpingotomy, usually using cautery or laser, is done to conserve the tube, and the products of conception are evacuated. Salpingectomy is indicated when ectopic pregnancies recur or are > 5 cm, when the tubes are severely damaged, or when no future childbearing is planned. Only the irreversibly damaged portion of the tube is removed, maximizing the chance that tubal repair can restore fertility. The tube may or may not be repaired simultaneously. After a cornual pregnancy, the tube and ovary involved can usually be salvaged, but occasionally repair is impossible and hysterectomy is necessary.
If unruptured tubal pregnancies are ≤ 3.0 cm in diameter, no fetal heart activity is detected, and β-hCG level is < 5,000 mIU/mL ideally but < 15,000 mIU/mL certainly, women can be given a single dose of methotrexate 50 mg/m2 IM. β-hCG measurement and ultrasonography are repeated on about days 4 and 7. If the β-hCG level does not decrease ≥ 15%, a 2nd dose of methotrexate or surgery is needed. About 10 to 30% of women treated with methotrexate eventually require a 2nd dose. Success rates with methotrexate are about 87%; 7% of women have serious complications (eg, rupture). Surgery is indicated when methotrexate is inappropriate (eg, β-hCG level > 15,000 mIU/mL) or ineffective.
Last full review/revision November 2005
Content last modified November 2005
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