Ectopic pregnancy: Causes, Symptoms, Diagnosis, and Complications | Medical Management of Ectopic Pregnancy

 Ectopic Pregnancy

Introduction

Description: An ectopic pregnancy is one in which the fertilized egg is implanted outside of the endometrial cavity ( fallopian tube [98%], ovary, abdominal cavity, or cervix). This is the leading cause of pregnancy-related maternal death in the first trimester (4%-10% of all Pregnancy-related deaths).

Prevalence: 10-15 of 1000 pregnancies; varies with age, race and location.

Predominant Age: 25-34 years (>50%).

Genetics: No genetic pattern.

Etiology and Pathogenesis

 Causes 

• Tubal damage or altered motility causes the fertilized egg to be improperly transported, resulting in implantation outside the uterine cavity. The most common cause is acute salpingitis (50%). In the majority of the remaining patients (40%), no risk factor is apparent. Abnormal embryonic development may play a role.

Risk Factors 

• Tubal damage ( pelvic infections; six-fold increased risk), prior ectopic pregnancy ( 10-fold increased risk), prior female sterilization, age 35-44 years (three-fold greater rate of extrauterine gestations than for women aged 15-24 years), non-white race ( 1.5-fold increased risk), assisted reproduction ( two-fold increased risk), cigarette smoking ( 30+/day: three-to five-fold increased risk), intrauterine contraceptive device (IUCD) use, and endometriosis. More than half of cases occur in women who have been pregnant three or more times.

Signs and Symptoms

• Normal signs and symptoms of pregnancy ( amenorrhea, uterine softening).
• Acute abdominal pain ( dull, crampy, or colicky).
• Evidence of intra-abdominal bleeding, including hypotension and collapse. 
• Adnexal mass ( with or without tenderness).
• Vaginal bleeding.
• Signs of peritoneal irritation.
• Absence of a gestational sac on ultrasonography with β-human chorionic gonadotropin ( β-hcg) level >2000 mIU/mL.
• Abdominal pregnancy may be asymptomatic until the near term.

Diagnostic Approach 

Differential Diagnosis

• Appendicitis
• Degenerating fibroid
• Dysfunctional uterine bleeding
• Endometriosis
• Gastroenteritis
• Mesenteric thrombosis
• Ovulation
• Ruptured corpus luteum cyst
• Salpingitis
• Septic abortion ( fever >38°C or a white blood count of >20000 WBC/dL is rare in patients with ectopic pregnancies; the presence of either should suggest a pelvic infection, including septic abortion).
• Threatened or incomplete abortion.
• Torsion of a an adnexal mass.

Associated Conditions: pelvic inflammatory disease, infertility, and recurrent abortion.

Workup and Evaluation

Laboratory

• Serial quantitative β-hCG levels ( if patients condition permits; 85% of viable pregnancies demonstrate a rise of at least 66% every 48 hours during the first 40 days of pregnancy). Levels are lower than 3000 mIU/mL in approximately half of ectopic pregnancies. Serum progesterone (low) may be diagnostic help if less than 6 weeks gestation ( almost 90% of patient with an ectopic pregnancy have levels less than 30 nM/L [10 ng/mL]). A hematocrit level of less than 30% is found in approximately one-fourth of women with ruptured ectopic pregnancy.

Imaging 

• Ultrasonography ( transvaginal preferred) may be augmented by colour-flow Doppler studies.

Special Tests 

• Culdocentesis has largely been replaced by ultrasonography.

Diagnostic Procedures

• History and physical examination, serum β-hCG level and ultrasonography, When laparoscopy is used as a diagnostic tool, there is a 2%-5% chance of a false-positive or false-negative diagnosis.

Pathologic Findings

• Placenta villi invading tissue other than the endometrium. Most ectopic pregnancies are tubal, with the ampulla ( approximately 80% ) and isthmus (12%) being the most common locations and 5% in the fimbrial region.

Medical Management and Therapy

Nonpharmacologic 

General Measures

• Rapid assessment and general support when intra-abdominal bleeding present.

Specific Measures

• Expeditious diagnosis ( diagnostic delay is a factor in approximately half of all deaths associated with ectopic pregnancy; 50% of patients have had one or more visits to a healthcare provider before the diagnosis is made, even in nonfatal cases). Surgical intervention generally is required for symptomatic patients ( salpingostomy, salpingostomy). Medical therapy may be considered for asymptomatic or mildly symptomatic patients.

Diets

• In acute rupture, nothing by mouth in anticipation of possible surgical intervention. If medical therapy is used, avoid folate supplements and folate-containing preparations.

Activity

• No restriction except those dictated by the patient's status.

Drugs of Choice

• Methotrexate IM 50 mg/m2 surface area with a maximum of 80 mg.

Contraindications

• Methotrexate should not be used if the β-hCG level is greater than 5000 mIU/mL, the adnexal mass is greater than 3-4 cm, or the patient's hemodynamic status is unstable. Patient with a history of active hepatic or renal disease, fetal cardiac activity demonstrated in the ectopic gestation, active ulcer disease, or significant alterations in blood count ( white blood cell count <3000, platelet count of <100,000) are generally not considered for this therapy.
• All women with ectopic pregnancies who are Rh-negative and unsensitized should receive Rh immunoglobulin at a dose of 50 ug if the gestation is of less than 12 weeks duration and 300 ug if it is beyond 12 weeks.

Precautions

• A transient increase in abdominal Symptoms is often encountered 48-72 hours after methotrexate therapy. Approximately 5%-10% of medically managed patients experience Complications before medical therapy can be effective, necessitating surgical intervention.

Interactions

• If patients are receiving methotrexate therapy, they should not take multivitamins with folic acid ( e.g prenatal vitamins) because this counteracts the effects of the methotrexate.

Follow up 

Patient Monitoring 

• Follow-up assessment of serum β-hCG level to confirm a decline toward normal.

Prevention/Avoidance

• Reduce modifiable risk factors, such as pelvic infections.

Possible Complications

• Rupture of an ectopic pregnancy dooms the pregnancy and may result in catastrophic intra-abdominal bleeding that jeopardises the life of the mother. It is the most common cause of maternal death in the first half of pregnancy. Maternal mortality from ectopic pregnancy has declined with earlier detection made possible by laboratory and ultrasonography diagnosis. Current statistics suggest a rate of 3.8 of 10,000 patients. Maternal death is most often associated with blood loss and delay in diagnosis.