Marta Pombo Shares Curious Story of Two Positive Pregnancy Tests

Marta Pombo, sister of influencer María Pombo, reported a false positive result on two separate pregnancy tests, a clinical occurrence that often stems from biological interference or specific medical conditions. According to Pombo’s public account, the resolution of the situation confirmed that she was not pregnant despite the initial diagnostic indicators.

The phenomenon of a false positive pregnancy test is rare but medically significant, as it often signals a gap between a rapid screening tool and a definitive clinical diagnosis. While most over-the-counter tests boast high sensitivity and specificity, they are designed to detect the presence of the hormone human chorionic gonadotropin (hCG). When a test returns a positive result without a viable pregnancy, it suggests the presence of hCG from a non-gestational source or a chemical interference with the test’s antibodies.

For individuals experiencing contradictory test results or unexpected positives, immediate triage is necessary. It is highly recommended to consult with [Board-Certified Endocrinologists] or [Reproductive Health Specialists] to perform a differential diagnosis and rule out hormonal imbalances or systemic issues.

Why do pregnancy tests produce false positives?

False positives typically occur through one of three mechanisms: chemical interference, biochemical “ghost lines,” or the production of hCG by non-placental tissues. According to the National Center for Biotechnology Information (NCBI), the most common cause of a true false positive is the presence of heterophilic antibodies. These are antibodies produced by the patient’s immune system that can bind to the antibodies on the test strip, mimicking the presence of hCG.

Another clinical possibility involves the “hook effect,” though this more commonly leads to false negatives in very high concentrations. Conversely, certain medications—specifically those containing hCG used in fertility treatments—can trigger a positive result if administered shortly before testing. This creates a clinical gap where the patient perceives a pregnancy that is actually a pharmacological residue.

Medical practitioners often look for “phantom hCG” produced by certain types of tumors, such as germ cell tumors or gestational trophoblastic disease. While rare, these conditions represent a serious morbidity risk if not identified through professional screening. Patients who encounter this scenario should seek evaluation at [Diagnostic Imaging Centers] for an ultrasound to confirm the absence of an intrauterine pregnancy.

How is a false positive distinguished from a chemical pregnancy?

A critical distinction exists between a false positive and a “chemical pregnancy,” which is a very early miscarriage that occurs shortly after implantation. In a chemical pregnancy, the woman was briefly pregnant; the embryo implanted, hCG was produced, and the test was technically correct, but the pregnancy failed to progress. In a true false positive, as experienced by Marta Pombo, no pregnancy ever occurred.

To resolve this ambiguity, clinicians follow a standard of care involving quantitative serum testing. Unlike qualitative urine tests, which provide a binary “yes/no,” quantitative tests measure the exact amount of beta-hCG in the blood. According to guidelines published by the American College of Obstetricians and Gynecologists (ACOG), a rising trend of hCG over 48 hours typically indicates a viable pregnancy, while a flat or declining level suggests either a chemical pregnancy or a non-gestational source of the hormone.

The pathogenesis of non-gestational hCG can also be linked to kidney failure, as the kidneys are responsible for clearing hCG from the blood. When renal function is impaired, hCG levels may accumulate, potentially interfering with the accuracy of rapid tests. This necessitates a multidisciplinary approach, often requiring coordination between [Nephrology Clinics] and obstetricians to ensure patient stability.

What are the clinical implications of “ghost lines”?

Many users report “evaporation lines” or “ghost lines,” which are faint streaks that appear after the test’s recommended read-time has passed. These are not biological positives but rather the result of the urine evaporating and leaving a residue on the test strip. This is a common point of confusion in home diagnostics and highlights the necessity of adhering strictly to the manufacturer’s timing instructions.

The risk of misinterpreting these lines can lead to significant psychological distress and unnecessary medical interventions. To avoid such outcomes, the World Health Organization (WHO) emphasizes the importance of using standardized diagnostic protocols. When home tests yield ambiguous results, the gold standard remains the transvaginal ultrasound, which can visualize the gestational sac and fetal heartbeat, providing a definitive resolution.

For healthcare providers, managing these cases requires a balance of empathy and scientific rigor. Ensuring that patients have access to vetted [Women’s Health Diagnostic Centers] prevents the delay of treating the underlying cause of a false positive, such as an endocrine disorder or an occult malignancy.

As diagnostic technology evolves, the integration of more specific monoclonal antibodies in home tests may reduce the incidence of heterophilic antibody interference. However, until these advancements become standard, the transition from a home screen to a clinical laboratory remains the only way to achieve absolute diagnostic certainty. Those seeking clarity on hormonal health or unexplained test results should engage with certified medical professionals to ensure a comprehensive health audit.

Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.