What are the immediate steps to take if an ectopic pregnancy is suspected?

Immediate Management of Suspected Ectopic Pregnancy

If ectopic pregnancy is suspected, immediately obtain quantitative serum β-hCG, complete blood count, blood type with Rh status, and perform transvaginal ultrasound regardless of the hCG level—these four tests form the cornerstone of initial evaluation and must be done simultaneously, not sequentially. 1

Immediate Hemodynamic Assessment

Assess hemodynamic stability first—this determines whether the patient needs emergency surgery or can proceed with diagnostic workup. 1, 2

• Check vital signs for hypotension, tachycardia, or orthostatic changes indicating hemorrhage 2
• Examine for peritoneal signs (rebound tenderness, guarding, rigidity) which indicate rupture requiring immediate surgery 1, 2
• Evaluate for shoulder pain, which suggests diaphragmatic irritation from hemoperitoneum 3

If the patient is hemodynamically unstable or has peritoneal signs, initiate resuscitation with blood products and obtain immediate obstetrics/gynecology consultation for emergency surgery—do not delay for complete diagnostic workup. 2, 4

Transvaginal Ultrasound Evaluation

Perform transvaginal ultrasound immediately regardless of β-hCG level, as approximately 22% of ectopic pregnancies occur at hCG levels <1,000 mIU/mL. 1

The ultrasound must specifically evaluate:

• Intrauterine cavity: Look for definitive intrauterine pregnancy (gestational sac with yolk sac or fetal pole)—this essentially excludes ectopic pregnancy in spontaneous conceptions 5, 1
• Adnexa: Search for extrauterine gestational sac, tubal ring (hyperechoic periphery with fluid center), or nonspecific heterogeneous adnexal mass 5, 1
• Cul-de-sac: Assess for free fluid, particularly echogenic fluid suggesting hemoperitoneum 5, 1

A common pitfall is assuming that a low β-hCG level excludes ectopic pregnancy—never exclude ectopic pregnancy based on a single low β-hCG value alone, as ectopic pregnancy can occur at any hCG level. 1

Risk Stratification Based on Initial Findings

High-Risk: Immediate Surgical Intervention Required

Obtain immediate obstetrics/gynecology consultation for surgery if any of the following are present: 1, 2

• Hemodynamic instability 1, 2
• Peritoneal signs 1, 2
• Confirmed ectopic pregnancy with fetal cardiac activity visualized 1
• Significant hemoperitoneum on ultrasound, even if vital signs are temporarily stable 2

Confirmed Ectopic Pregnancy (Stable Patient)

If ultrasound shows definitive ectopic pregnancy (extrauterine gestational sac with yolk sac or embryo) in a stable patient, obtain obstetrics/gynecology consultation for either medical or surgical management. 1, 6

Before considering methotrexate, assess candidacy:

• Pre-treatment labs: Complete blood count with differential and platelets, hepatic enzymes, renal function 1, 3
• Absolute contraindications: Alcoholism, active liver disease, immunodeficiency, active peptic ulcer disease, active pulmonary/renal/hematopoietic disease 1, 3
• Relative contraindications: Ectopic mass >3.5 cm, embryonic cardiac activity, β-hCG ≥5,000 mIU/mL 1, 3

Methotrexate is never appropriate for ruptured ectopic pregnancy or hemodynamically unstable patients. 2, 3

Pregnancy of Unknown Location (PUL)

If ultrasound shows no intrauterine pregnancy and no definitive ectopic pregnancy, this is a pregnancy of unknown location—most of these will be nonviable intrauterine pregnancies, but 7-20% will ultimately be ectopic. 5, 1

For stable patients with PUL:

• Arrange repeat quantitative β-hCG in 48 hours 1, 3
• Schedule follow-up transvaginal ultrasound when hCG reaches 1,000-2,000 mIU/mL range 5, 1
• Ensure patient understands warning signs requiring immediate return: severe abdominal pain, hemodynamic symptoms (dizziness, syncope), heavy vaginal bleeding, shoulder pain 3

A critical pitfall is making the diagnosis of ectopic pregnancy based solely on absence of intrauterine pregnancy—the diagnosis should generally be based on positive findings, not solely on the absence of an IUP, to avoid inappropriate methotrexate or surgical intervention. 5

Critical Patient Counseling

All patients being discharged must understand these warning signs requiring immediate return: 3

• Severe abdominal pain (may indicate rupture) 3
• Signs of hemodynamic instability (dizziness, syncope, severe weakness) 3
• Heavy vaginal bleeding 3
• Shoulder pain (indicates diaphragmatic irritation from blood) 3

For patients receiving methotrexate, emphasize that increasing pain after treatment may represent either expected treatment effect or rupture—they must return immediately for evaluation of any severe pain. 3

Rh Status Management

Administer Rh immunoglobulin to all Rh-negative patients with suspected or confirmed ectopic pregnancy to prevent alloimmunization. 2, 3