Resultados Conflitantes de Testes de Gravidez: Como Resolver a Discordância

Discordant results (one positive, one negative) require systematic resolution. Don't guess—test definitively.

Common Scenarios

• Different test sensitivities: 10 mIU/mL test positive; 25 mIU/mL test negative → hCG between 10–25.
• Urine concentration variation: First-morning positive; afternoon negative.
• Timing: Early pregnancy; hCG near threshold.
• User error: One test performed incorrectly.
• Evaporation line: Read after window → false positive on one.
• Chemical pregnancy: hCG falling between tests.
• Heterophilic antibodies: Rare interference causing false positive on one assay.

Definitive Resolution

1. Quantitative serum β-hCG: Gold standard; provides exact value and trend.
2. Repeat in 48 hours: Rising → viable; falling → chemical/ectopic; static → indeterminate.
3. Transvaginal ultrasound: When hCG >1,500–2,000 mIU/mL.

Immediate Advice

• Assume pregnant until proven otherwise (precautionary principle).
• Avoid alcohol, teratogens, hot tubs.
• Start prenatal vitamin if not already.
• Contact provider for blood test order.

Do not rely on home test discordance; blood test settles it.