Mira vs Ultrasound: 2026 Clinical Study Results

890 ultrasound scans. 121 ovulatory cycles. One question: does what you measure at home match what a clinic sees?

The short answer: In a blinded, STARD-compliant clinical study published in Reproductive BioMedicine Online (Bouchard et al., 2026), ovulation confirmed by transvaginal ultrasound occurred within ±1 day of the LH peak measured by Mira in 96% of ovulatory cycles. Researchers tracked 121 ovulatory cycles and 890 ultrasound scans over 18 months.

At a glance*

96% of ovulations fell within ±1 day of Mira's LH peak (R² = 0.96)
0.97 intraclass correlation with ultrasound-confirmed ovulation day: excellent agreement
R² = 0.92 between Mira urine LH and blood LH
11% of cycles were anovulatory, even in women with regular periods
5–6 days: how early estrogen (E13G) started rising before ovulation

*Based on a blinded clinical study of 121 ovulatory cycles with 890 ultrasound scans (Bouchard et al., 2026). Findings should not be used for clinical decision-making.

As covered in FemTech World

"At-home ovulation test nearly as accurate as ultrasound, research finds" — FemTech World, September 18, 2026

Headline from independent third-party coverage; it reflects the publication's wording, not a Mira claim. Mira is not designed to replace ultrasound or clinical care.

What did the study test?

The study compared Mira's at-home urine hormone readings against the two methods fertility clinics rely on: serial transvaginal ultrasound to confirm ovulation, and serum blood tests.

Led by Dr. Thomas P. Bouchard, MD, the research ran prospectively for 18 months. Participants tested first-morning urine with Mira, and blood was drawn within 90 minutes of each urine sample.

Mira measured four hormones as actual numbers, not yes/no lines:

LH (luteinizing hormone), which surges before ovulation
E13G, a urine metabolite of estrogen, which rises as follicles grow
PDG, a urine metabolite of progesterone, which rises after ovulation
FSH (follicle-stimulating hormone), which drives follicle development

What does "blinded" and "STARD-compliant" mean? Blinded means ultrasound and hormone results were assessed independently, so one couldn't influence the other. STARD is the international reporting standard for diagnostic accuracy studies, the framework researchers use to show a test was evaluated rigorously and transparently.

What did the study find?

How closely does Mira's LH peak match ultrasound-confirmed ovulation?

Very closely. Ovulation confirmed by ultrasound occurred within ±1 day of Mira's LH peak in 96% of ovulatory cycles (R² = 0.96, P < 0.001). The intraclass correlation was 0.97, which researchers classify as excellent agreement.

Do urine hormones reflect blood hormone levels?

Yes. First-morning urine readings from Mira closely mirrored serum levels drawn within 90 minutes.

Hormone	Urine vs blood correlation (R²)	Strength
LH	0.92	Extremely strong
PDG (progesterone metabolite)	0.75	Very strong
E13G (estrogen metabolite)	0.73	Very strong
FSH	0.61	Strong

Does ovulation always happen at the LH peak?

Not always. In 12.4% of cycles, ovulation happened while LH was still rising. Most ovulations (83.4%) fell on the day of the peak or the day after. That's why a single positive LH strip can't tell the whole story.

When does the fertile window start?

Earlier than LH alone suggests. Urinary estrogen (E13G) began rising about 5–6 days before ovulation, reflecting real follicle growth and flagging the fertile window before the LH surge.

Can you skip ovulation even with regular periods?

Yes. Even among women with regular periods, 11% of cycles were anovulatory. A regular calendar doesn't guarantee an egg was released.

Is every cycle the same?

No. The follicular phase ranged from 10 to 29 days across cycles, and LH surges took different shapes: narrow, broad and two-day peaks. Your body doesn't run on a fixed schedule.

Why does this study matter?

It updates a 25-year-old benchmark. A widely cited earlier validation of an at-home fertility monitor against ultrasound was published in 2000: Behre et al., "Prediction of ovulation by urinary hormone measurements with the home use ClearPlan Fertility Monitor," in Human Reproduction. That monitor tracked two hormones, LH and an estrogen metabolite, and displayed fertility levels rather than hormone values.

The 2026 study builds on that work with a different design: four hormones measured as numbers, a blinded protocol and STARD reporting standards. The study authors describe it as, to their knowledge, the first STARD-compliant, blinded validation of a multi-hormone urine monitor against ultrasound-confirmed ovulation in over 25 years.

"For over two decades, at-home fertility tracking was based on qualitative indicators without providing quantitative hormone values." — Dr. Thomas P. Bouchard, MD, lead author

The authors concluded that validated at-home urine hormone tracking supports broader clinical adoption and could potentially reduce reliance on routine clinic visits.

What does this mean if you're tracking your cycle?

You can see more than a predicted date. With Mira, you track hormone patterns at home to see whether and when ovulation occurs, and how your cycle shifts month to month.

Test with first-morning urine. In the study, first-morning samples showed the strongest agreement with blood hormone levels, which is why Mira recommends testing first thing.
Watch estrogen, not only LH. In the study, E13G began rising 5–6 days before ovulation, an earlier signal of the fertile window.
Look past the LH peak. Mira shows your PdG (progesterone metabolite) levels after your LH peak, so you can see how your hormones change in the second half of your cycle.
Expect variation. Different cycle lengths and LH shapes are normal. Tracking over several cycles shows your pattern.

"Women deserve precise biological data about their reproductive health without needing constant clinic visits and serial blood draws." — Sylvia Kang, Founder and CEO, Mira

Start tracking with Mira →

Based on a blinded clinical study of 121 ovulatory cycles with 890 ultrasound scans. Findings should not be used for clinical decision-making. Mira is not intended to replace medical care; talk to your healthcare provider about your results.

FAQ

How accurate is Mira compared to ultrasound? In a blinded 2026 clinical study, ultrasound-confirmed ovulation occurred within ±1 day of Mira's LH peak in 96% of ovulatory cycles, across 121 cycles and 890 ultrasound scans. Findings should not be used for clinical decision-making.

Can Mira replace an ultrasound? No. Mira is not designed to replace ultrasound or clinical care. The study authors concluded that validated at-home hormone tracking could potentially reduce reliance on routine clinic visits. Always follow your healthcare provider's guidance.

Which hormones does Mira measure? Mira measures LH, E13G (estrogen metabolite), PDG (progesterone metabolite) and FSH as quantitative values, depending on the wand used.

Why should I test with first-morning urine? First-morning samples showed the strongest agreement with blood hormone levels in the study. Hormones fluctuate through the day, so morning testing gives the most consistent reading.

Can I not ovulate even if my periods are regular? Yes. In the study, 11% of cycles in women with regular periods were anovulatory, meaning no egg was released. Mira does not diagnose anovulation; if you're concerned about your cycles, talk to your healthcare provider.

How early does the fertile window start? In the study, urinary estrogen began rising about 5–6 days before ovulation, earlier than the LH surge.

Where was the study published? In Reproductive BioMedicine Online (Bouchard et al., 2026), a peer-reviewed journal. DOI: 10.1016/j.rbmo.2026.105881.