Tubal pregnancy refers to the implantation of a fertilized egg in the fallopian tubes. The most common site of implantation is the ampulla.
Presentation
Severe lower quadrant pain, sudden in onset, stabbing, intermittent and without radiation, is present in almost 100% cases. Pain can be unilateral or bilateral, localized or generalized. Backache may be present during attacks. Secondary amenorrhea varies, as nearly half of women with tubal pregnancies have some spotting at the time of their expected menses and thus do not realize they are pregnant.
Abdominal distention and mild paralytic ileus are often seen. Palpable mass in the pelvic region, and diffuse abdominal tenderness is noticed. Uterine changes of pregnancy and peritoneal accumulation of blood may be present. Heavy intraabdominal bleed can lead to altered consciousness. Vital signs should be examined to assess the hemodynamic stability of the patient.
Workup
The key components to the diagnosis of tubal pregnancy include physical findings, transvaginal ultrasonography (TVS), serum β-hCG level measurement – both the initial and the subsequent patterns of rise or decline, and diagnostic surgery, which includes curettage, laparoscopy, and occasionally laparotomy.
- Blood tests: All relevant serum levels including β-human chorionic gonadotropin (β-hCG) are at a lower range than the expected in a normal pregnancy. Monitoring β-hCG levels is important. Decreased levels over a period of time can be an indicator of spontaneous abortion.
- Transvaginal ultrasound (TVS): β-hCG titers and ultrasound complement each another in early detection of tubal pregnancy. When β-hCG levels are around 1000 mIU/mL TVS detects a well visible intrauterine sac. When an empty sac is seen with or without adnexal mass at same β-hCG levels, ectopic pregnancy can be suspected [8].
Treatment
- Medical therapy: All patients with tubal pregnancy must be closely monitored. In a stable patient, methotrexate (50 mg/m2) intramuscularly can be given as single or multiple doses for early tubal pregnancy. The pregnancy should be < 3.5 cm in largest dimension and unruptured, with no active bleeding and no fetal heart tones. The use of methotrexate in an unstable patient is absolutely contraindicated [9].
- Surgical therapy: Surgical treatment is definitive, and can be planned for all cases but is absolutely indicated for an unstable patient with a tubal pregnancy. The patient is hospitalized, and blood is typed and cross-matched. Diagnostic laparoscopy is the initial surgical procedure performed. The plan of surgery depends on size of the ectopic pregnancy. Removal of fallopian tube either partially or completely along with ectopic is planned accordingly [10].
- Postoperatively, iron therapy for anemia may be necessary during convalescence. Rho(D) immune globulin (300 mcg) should be given to Rh-negative patients because sensitization may occur.
Prognosis
Tubal pregnancy can end up with abortion or rupture. The mortality from tubal pregnancy is around 0.2 per 100 cases. Isthmic pregnancies tend to rupture earliest, at 6 to 8 weeks' gestation. Interstitial pregnancies are the last to rupture, usually at 12–16 weeks and can result in massive hemorrhage due to their proximity to uterine and ovarian vessels. More than 85 % of women can be diagnosed with accurate determination of low β-hCG and diagnostic ultrasound, allowing preservation of tube and future fertility. There is a 10 to 20% chance of another ectopic pregnancy, and the patient requires careful observation and early ultrasound confirmation of an intrauterine pregnancy in the future [6] [7].
Etiology
Predisposing risk factors are found in only two third of cases. Tubal pregnancy is more often associated with fertility treatments and intrauterine contraceptive devices (IUD). Tubal surgery, reanastomosis of tubectomy, previous ectopic pregnancy, in-utero exposure to diethylstilbestrol, documented tubal pathology and use of IUD are high risk factors. Infertility, previous genital infections, and multiple sexual partners are associated with moderate risk of tubal pregnancy. Smoking and past surgeries are also risk factors. Multiple previous elective abortions and failure of progesterone only contraceptives are important associations [2] [3].
Epidemiology
The rate of ectopic pregnancy is approximately 1 % of pregnancies. The mortality rate is high in women who do not have access to medical care. Undiagnosed or undetected ectopic pregnancy is the most common cause of maternal death during the first trimester in many developed countries [4].
Pathophysiology
The implantation in tubal pregnancy takes place under the serosa inside the connective tissue of the fallopian tube. There is little decidual reaction to the permeating trophoblast leading it to invade blood vessels causing local hemorrhage. As the pregnancy progresses, the hematoma in the subserosal space enlarges. Progressive distention of the tube eventually leads to rupture. Tubal pregnancy includes ampullary type (55%), isthmic type (25%), fimbrial type (17%) and interstitial type. Uterine decidual sloughing can lead to vaginal bleeding. Superficial secretory endometrium usually is present, but no trophoblastic cells are seen [5].
Prevention
A large number of tubal pregnancies can be avoided by prevention and timely treatment of sexually transmitted diseases. It is important to maintain a high index of suspicion in case of suggestive symptoms and diagnose tubal pregnancies early to reduce morbidity, mortality and late sequelae.
Summary
A tubal pregnancy occurs when a fertilized ovum implants in the fallopian tube instead of the endometrial lining of the uterus. It is the most common type of ectopic pregnancy. Other sites of ectopic implantation are the peritoneum or abdominal viscera, the ovary, and the cervix.
Tubal pregnancy commonly presents with abdominal and pelvic pain, missed period and vaginal bleeding. Diagnosis is made with a transvaginal ultrasound. Tubal pregnancy requires an emergency management to prevent the potentially life-threatening complication of tubal rupture. Medical management includes systemic methotrexate and surgical treatment consists of laparoscopic salpingectomy [1].
Patient Information
- Definition: A tubal pregnancy is when a fertilized egg implants itself outside of the womb, in one of the fallopian tubes. The egg thus implanted cannot grow into a baby, and also poses danger to the woman’s health because of the possibility of the tube getting ruptured.
- Cause: Factors causing tubal dysfunction lead to inability of the fertilized egg to move to the womb from the fallopian tube. These include previous infection of tubes, pelvic inflammatory disease (PID) which may be due to various causes including sexually transmitted diseases, problems of the appendix and previous tubal surgery.
- Symptoms: Symptoms appear between the fifth and fourteenth weeks of pregnancy, and include missed periods, mild to severe pain in abdomen, usually on one side and abnormal vaginal bleeding. Sometimes a tubal pregnancy may not cause any noticeable symptoms except those of pregnancy and may be diagnosed during routine pregnancy testing. In case of rupture, there is a sudden severe pain, feeling of nausea and faintness, and sometimes diarrhea and pain in shoulder tip. Rupture causes massive internal bleeding and can be life threatening.
- Diagnosis: The best way to diagnose a tubal pregnancy is by doing an ultrasound examination of the reproductive organs with the help of a probe placed inserted into the vagina.
- Treatment and follow-up: Tubal pregnancy, when detected very early, may be managed with a drug called methotrexate. Methotrexate prevents the egg from developing and the pregnancy tissue is then absorbed into the body. A later diagnosis of tubal pregnancy requires surgery to remove the egg, which is usually done with the help of a laparoscope.
References
- Murray H, Baakdah H, Bardell T, Tulandi T. Diagnosis and treatment of ectopic pregnancy. CMAJ 2005; 173:905.
- Bouyer J, Coste J, Shojaei T, et al. Risk factors for ectopic pregnancy: a comprehensive analysis based on a large case-control, population-based study in France. Am J Epidemiol 2003; 157:185.
- Pisarska MD, Carson SA, Buster JE. Ectopic pregnancy. Lancet 1998; 351:1115.
- Zane SB, Kieke BA Jr, Kendrick JS, Bruce C. Surveillance in a time of changing health care practices: estimating ectopic pregnancy incidence in the United States. Matern Child Health J 2002; 6:227.
- Senterman M, Jibodh R, Tulandi T. Histopathologic study of ampullary and isthmic tubal ectopic pregnancy. Am J Obstet Gynecol 1988; 159:939.
- Clausen I. Conservative versus radical surgery for tubal pregnancy. A review. Acta Obstet Gynecol Scand. Jan 1996; 75(1):8-12.
- Ory SJ, Nnadi E, Herrmann R, O'Brien PS, Melton LJ 3rd. Fertility after ectopic pregnancy. Fertil Steril. Aug 1993; 60(2):231-5
- Kirk E, Papageorghiou AT, Condous G, et al. OC59: A single transvaginal ultrasound examination as a test for ectopic pregnancy. Ultrasound Obstet Gynecol. 2007; 30:385.
- Lipscomb GH. Medical therapy for ectopic pregnancy. Semin Reprod Med 2007; 25:93.
- Mol F, van Mello NM, Strandell A, et al. Salpingotomy versus salpingectomy in women with tubal pregnancy (ESEP study): an open-label, multicentre, randomised controlled trial. Lancet 2014; 383:1483.