Qualitative Serum hCG Optimal Testing Recommendations

  • Use to screen for possible pregnancy.
  • Test results should be confirmed using a quantitative hCG assay prior to the performance of any critical medical procedure.

Guidelines for Test Utilization

What does the test tell me?

A positive hCG measurement indicates the presence of chorionic gonadotropin hormone in the circulation, with the most likely source being the placenta and indicative of pregnancy.

When should I order this test?

Use any time there is suspicion of possible pregnancy.

When should I NOT order this test?

For questions of pregnancy viability or for use as a trophoblast or gonadal tumor marker, a quantitative hCG is recommended instead.

How should I interpret the result?

A positive hCG test is consistent with pregnancy or a condition in which hCG is produced.

A negative hCG test does not rule out very early pregnancy due to its low negative predictive value during this stage.

Is the test result diagnostic/confirmatory of the condition?

A positive hCG result is considered diagnostic for pregnancy when in agreement with clinical exam and patient history.

Are there factors that can affect the lab result?

Heterophilic antibody interference has been reported. Women working or living with farm animals or treated with monoclonal antibody therapies are at highest risk.

Elevated leukocyte concentrations may cause false positive results in hCG assays.

HCG testing may not be valid in patients taking high dose biotin supplements and having certain qualitative tests.

Are there considerations for special populations?

False-negative results most commonly occur in pregnancies before 4 weeks of gestation.

Women at or near menopause (> 40 years) may have low detectable hCG from pituitary gland secretion; however, this low level is not commonly detected by qualitative testing.

What other test(s) might be indicated?

Quantitative hCG measurement can be used to assess pregnancy viability with levels expected to approximately double every 24-48 hours through 10-12 weeks of gestation. If serum hCG assays are unavailable, urine hCG test may be used.

References

Greene DN, Grenache DG; Education Committee of the Academy of Clinical Laboratory Physicians and Scientist. Pathology consultation on human chorionic gonadotropin testing for pregnancy assessment. Am J Clin Pathol. 2015 Dec; 144(6):830-6.

Greene DN, Schmidt RL, Kamer SM, Grenache DG, Hoke C, Lorey TS. Clin Limitations in qualitative point of care hCG tests for detecting early pregnancy. Chim Acta. 2013 Jan 16; 415:317-21.

Furtado LV, Lehman CM, Thompson C, Grenache DG. Should the qualitative serum pregnancy test be considered obsolete? Am J Clin Pathol. 2012 Feb;137(2):194-202.

Williams GR, Cervinski MA, Nerenz RD. Assessment of biotin interference with qualitative point-of-care hCG test devices. Clin Biochem. 2018 Mar;53:168-170.



Last reviewed: June 2020. The content for Optimal Testing: AACC's Guide to Lab Test Utilization has been developed and approved by the AACC Academy and AACC's Science and Practice Core Committee.

As the fields of laboratory medicine and diagnostic testing continue to grow at an incredible rate, the knowledge and expertise of clinical laboratory professionals is essential to ensure that patients received the highest quality and most useful laboratory tests. AACC's Academy and Science and Practice Core Committee have developed a test utilization resource focusing on commonly misused tests in hospitals and clinics. Improper test utilization can result in poor patient outcomes and waste in the healthcare system. This important resource geared toward medical professionals recommends better tests and diagnostic practices. Always consult your laboratory director to make sure these recommendations are appropriate for your patient population.