What is the best indicator that the client is experiencing an ectopic pregnancy?

Ectopic Pregnancy

Ectopic pregnancy is often one of the most difficult gynecologic lesions to diagnose.13 The incidence of ectopic pregnancy is estimated to be 0.64% to 2.0%, although surveillance data is imprecise and limited for a variety of reasons.14 Ectopic pregnancy is the most common obstetric cause of maternal death in the first trimester.13 In a series of 300 consecutive cases of ectopic pregnancy, 50% of patients received medical evaluation at least twice before the correct diagnosis was made.

The clinical picture of ectopic pregnancy may include vascular collapse, pelvic pain, isolated rectal or back pain, amenorrhea, abnormal menses, shoulder pain, syncope, cervical or adnexal tenderness, adnexal mass, anemia, and leukocytosis. It is important to note that blood in the peritoneal cavity does not consistently correlate with peritoneal irritation, blood pressure, or pulse rate.15 In fact, bradycardia in the presence of significant intraperitoneal bleeding from a ruptured ectopic pregnancy is not unusual (Tables 57.1 and57.2).

Risk factors for an ectopic pregnancy include a history of salpingitis, use of an intrauterine contraceptive device, or tubal ligation; however, no combination of these signs, symptoms, or historical data is diagnostic of an ectopic pregnancy. To confuse the diagnosis further, a normal menstrual history is reported in approximately 50% of patients with an ectopic pregnancy. A urine pregnancy test may occasionally be negative.16 Though rarely seen, the combination of a uterine decidual cast (Fig. 57.7) and a positive pregnancy test is virtually pathognomonic of an ectopic pregnancy. A uterine cast is decidua that has been hormonally stimulated by the ectopic pregnancy but is passed vaginally when the tissue can no longer be supported. The cast is an outline of the uterine cavity, but it can be mistaken for products of conception if not inspected carefully. Therefore all tissue passed vaginally should be carefully inspected before being sent to the laboratory for analysis for products of conception. An ectopic pregnancy can occasionally occur in conjunction with an intrauterine pregnancy. Patients who have undergone a therapeutic abortion may actually have had an unrecognized ectopic pregnancy, hence the need for pathologic evaluation of any tissue obtained by uterine evacuation procedures.

The greater sensitivity of the serum and urine β-hCG assay, coupled with the increased availability of emergency medicine physicians trained to perform pelvic US, has greatly increased the chance of early diagnosis of unruptured and ruptured ectopic pregnancy.17 Urinary β-hCG tests are sensitive at 20 mIU/mL or greater and are positive 98% of the time in the first few weeks of pregnancy. However, ectopic pregnancy is often associated with very low production of this hormone.

Introduction

Ectopic pregnancy (EP) is defined as the implantation and development of a fertilized ovum anywhere outside of the uterine cavity. The insidious and potentially catastrophic nature of EP has historically made it one of the most feared conditions to occur in women of reproductive age. Because an undiagnosed EP can quickly result in the untimely death of an otherwise healthy patient, the diagnosis and treatment of this condition have been extensively studied. Mastery of the most current clinical and scientific knowledge surrounding this topic is important for all health practitioners who treat women and essential for those practitioners who focus exclusively on women's reproductive health.

Ectopic Pregnancy

Ectopic pregnancy occurs when the fertilized ovum implants outside the endometrial lining of the uterus. Death, infertility, and recurrent ectopic pregnancy are possible sequelae. The frequency of ectopic pregnancy is difficult to determine accurately but in the United States is approximately 5 to 20 per 1000 pregnancies.8

Hemorrhage from ruptured ectopic pregnancy is the leading cause of pregnancy-related maternal death during the first trimester and accounted for 2.7% of all pregnancy-related maternal deaths in the United States from 2011 to 2013.9 More than 30% of women who have had an ectopic pregnancy subsequently suffer from infertility, and 5% to 23% have a second ectopic pregnancy.10

The number of deaths from ectopic pregnancy has decreased in the United States since the 1970s. The case-fatality rate decreased from 35.5 deaths per 10,000 ectopic pregnancies in 1970 to 3.8 per 10,000 in 1989,11 and the ectopic pregnancy mortality ratio decreased from 1.15 deaths per 100,000 live births from 1980 to 1984 to 0.5 death per 100,000 live births from 2003 to 2007.12 The U.S. Centers for Disease Control and Prevention (CDC) attributes this decline to “improvements in the sensitivity, accuracy, and use of pregnancy testing, ultrasound for diagnosis, and improvements in therapeutic modalities, including laparoscopic surgery and medical management of ectopic pregnancy.”13 Maternal death from ectopic pregnancy is more common in women with less access to obstetric care including teens, racial minorities, and women with poor socioeconomic status.

Factors that alter the risk for ectopic pregnancy include (1) previous ectopic pregnancy; (2) treatment for infertility (e.g.,in vitro fertilization); (3) prior pelvic infection (e.g., pelvic inflammatory disease and ruptured appendix); (4) prior tubal surgery (e.g., tubal ligation or occlusion); and (4) advanced maternal age.14 However, one-third of patients with ectopic pregnancies have no identifiable risk factors. In women with an intrauterine device (IUD), the risk for ectopic pregnancy is lower than in the general population at 0 to 0.5 per 1000 women-years. However, in the rare event that a pregnancy occurs with an IUD present, the likelihood that it is ectopic is increased.15

The fertilized ovum can implant anywhere along the path of migration or in the abdominal cavity (Fig. 16.1). Most ectopic pregnancies (98%) aretubal (infundibular or fimbrial, 6%; ampullary, 78%; isthmic, 12%; interstitial or cornual, 2%). The remaining 2% implant on thecervix, vagina, orovary or elsewhere in theabdomen.16 An increasing number ofcesarean scar ectopic pregnancies, which may be on a continuum withearly placenta accreta, are being reported.

Medical Management

Methotrexate (MTX) therapy for ectopic pregnancy is a widely used medical alternative to surgery. Methotrexate is a folic acid antagonist that impairs DNA synthesis and cellular replication targeting rapidly proliferating cells such as trophoblasts. Although medical treatment of ectopic pregnancy is an appealing option for many patients, certain absolute contraindications exist to the use of the drug and are listed inTable 1. Among the most important of the contraindications to MTX therapy is the inability of the patient to comply with follow-up after initiation of therapy. Without the ability to monitor response to medication and provide additional doses if deemed appropriate, opportunities to prevent ectopic rupture could be missed. To ascertain whether a patient is eligible for MTX therapy, a comprehensive laboratory and medical evaluation should first be performed, including tests of renal and liver function, as well as a complete blood count. Treatment failure occurs when decline in hCG levels is deemed inadequate and surgery is required. In some cases, medication failure presents as tubal rupture requiring emergent surgery.

Relative contraindications to MTX treatment pertain to patient characteristics that reduce the odds of successful treatment. These include hCG levels of 5000 mIU/mL or greater, ultrasonographic evidence of an ectopic pregnancy with fetal heart activity, and an ectopic gestational mass measuring ≥ 3.5 cm in diameter. The strongest predictor for the efficacy of MTX treatment is the hCG concentration.

Three methotrexate treatment regimens exist: single-dose, two-dose, and multidose regimens (Table 2). These designations refer more to the number of intended doses in the protocol rather than the actual number or doses received by all patients. For any of the protocols, once hCG levels have declined by at least 15% between interval assessments, no additional doses of medication are required, but hCG must still be followed until complete resolution to ensure treatment efficacy. Although each regimen has demonstrated efficacy, only one small, randomized trial of comparative efficacy exists in which no significant difference between protocols was observed. A recent meta-analysis demonstrated that the risk of treatment failure was nearly 5 times higher in women receiving single-dose MTX than in those receiving multidose MTX (adjusted for confounders). Of note, the meta-analysis demonstrated that patients designated to receive single-dose therapy often received more than one dose and that patients getting multidose therapy often required fewer than four doses to be cured. The two-dose protocol aims to address these considerations, improving on the efficacy of single-dose MTX while not requiring more visits than are typically required for the single-dose protocol.

Side effects of MTX therapy occur in up to 30% of women; however, most of these resolve rapidly and are generally of minor consequence. Abdominal pain is common early in treatment and is of concern as a possible indicator of tubal rupture. A potential cause of this pain in nonacute patients can be tubal miscarriage. Additional potential side effects include nausea, vomiting, diarrhea, gastritis, stomatitis, and liver transaminitis. Serious side effects such as alopecia and neutropenia can occur but are extremely rare.

Basic Information

Manifestations of Disease

Ectopic Pregnancy

Ectopic pregnancy may be responsible for nearly 5% of maternal deaths in developing countries compared with <1% in developed countries.9 As in industrialized countries, pelvic inflammatory disease (PID) associated with sexually transmitted diseases (STDs) is the most important risk factor for ectopic pregnancy in developing countries. Late diagnosis, leading in almost all cases to complications requiring emergency surgical intervention account for high fatality rates in women suffering from ectopic pregnancy in Africa.56 Clinicians should be suspicious of ectopic pregnancy in any woman of reproductive age presenting with acute abdominal or pelvic symptoms. The diagnosis of ectopic pregnancy can be difficult and protracted, but may be aided by ultrasound and serum β-hCG. A positive pregnancy test and no visible gestational sac in the uterus on ultrasound should always make for a presumptive diagnosis of ectopic pregnancy and if the diagnosis is not immediately obvious should trigger further investigations and follow-up until the final outcome of the pregnancy is known.57 A culdocentesis that produces any amount of dark blood is virtually diagnostic of a ruptured or leaking ectopic pregnancy; this test is very simple and can be performed as part of the original gynaecological examination of the patient in the outpatient's department. The treatment of ectopic pregnancy is primarily surgical removal of the ectopic pregnancy, but medical management with methotrexate is successful for small, stable ectopic pregnancies with serum β-hCG concentrations <3000 IU/L.

Ectopic Pregnancy

Ectopic pregnancy occurs when a fertilized egg implants outside the endometrial lining of the uterus. The vast majority of these are found in the fallopian tubes. Many ectopic pregnancies resolve spontaneously by absorption into the mother’s body. If the mother’s life is threatened, it is ethical to remove the fetus in a case of an ectopic pregnancy but not to directly terminate the life of the fetus (e.g., by dissection). Recourse can also be made to employ medical management with less frequent need of surgery. Occasionally, an ectopic pregnancy is diagnosed with hemorrhage, and this requires immediate surgery to save the mother’s life.