Período Menstrual Atrasado com Teste de Gravidez Negativo: Causas e Abordagem Passo a Passo

A missed period with a negative home pregnancy test is a common clinical scenario with a structured diagnostic pathway.

Pregnancy-Related Causes

• Testing too early: Ovulação mais tarde do que o esperado; hCG não detectável ainda.
• Ectopic pregnancy: Slow-rising hCG; may stay below urine threshold.
• Very dilute urine: High fluid intake.
• Hook effect: Extremely high hCG (rare; molar, multiples).

Non-Pregnancy Causes of Missed Period

• Anovulation: PCOS, stress, weight change, excessive exercise, thyroid disorder, hyperprolactinemia, perimenopause.
• Medications: Hormonal contraceptives (especially depot, IUD), antipsychotics, chemo.
• Medical conditions: Thyroid disease, pituitary tumor, premature ovarian insufficiency.

Stepwise Approach

1. Repeat home test in 3–5 days with first-morning urine.
2. If still negative: quantitative serum β-hCG.
3. If hCG negative: evaluate for anovulation (TSH, prolactin, FSH, estradiol, androgen panel).
4. If hCG positive: transvaginal ultrasound for location/viability.
5. Progesterone challenge (medroxyprogesterone 10 mg × 10 days) to induce withdrawal bleed if anovulatory.

Most resolve with repeat testing; persistent amenorrhea warrants endocrine workup.