Observational studyReproductive biology and endocrinology : RB&E2026
Real-time intrauterine dissolved oxygen dynamics across the luteal phase: a potential non-invasive functional biomarker of endometrial status.
Observational study in Reproductive biology and endocrinology : RB&E, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
15 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAccurate, same-cycle assessment of endometrial readiness remains a major unmet need in assisted reproduction. Animal models have shown that spiral artery angiogenesis drives a midluteal rise in uterine oxygen tension, but direct, real-time measurements in humans have never been reported. We hypothesized that intrauterine dissolved O₂ profiling during the luteal phase could represent a potential functional, noninvasive biomarker of endometrial status.
methodsIn this prospective, observational pilot feasibility study, eight healthy women aged 18-35 years with regular menstrual cycles and BMI < 30 underwent serial intrauterine pO₂ measurements across the luteal phase during a single natural cycle. Measurements were scheduled approximately every 48 h from the day of the LH surge (LH + 0) up to LH + 13/14, with minor variations due to scheduling constraints. Dissolved oxygen was recorded using a 1 mm fiber optic microsensor positioned 1 cm from the uterine fundus under ultrasound guidance. The primary outcome was intrauterine pO₂ (Torr) across the luteal phase.
resultsTwo distinct intrauterine oxygenation profiles were identified. Four participants exhibited a "peak" pattern characterized by early luteal low pO₂ (< 15 Torr), followed by a sharp mid-luteal rise in pO₂ (40-45 Torr at LH + 4 to LH + 6, p < 0.0001), a short plateau, and a decline by LH + 8. One participant showed an earlier and abbreviated peak. The remaining four participants maintained pO₂ values < 35 Torr throughout the luteal phase ("no-peak" pattern). Post-hoc review of baseline screening data and follow-up participant interviews identified plausible physiological, pharmacological, or lifestyle-related factors that may influence endometrial vascular maturation in the no-peak subgroup.
conclusionsThis study provides the first in vivo characterization of real-time intrauterine oxygen dynamics across the luteal phase in women. Intrauterine pO₂ profiling identified distinct temporal oxygenation patterns across the luteal phase and may reflect physiologically relevant changes in endometrial function. These preliminary findings support further evaluation of intrauterine oxygen profiling as a potential non-invasive, same-cycle functional biomarker of embryo-endometrium synchrony. Larger studies are required to validate its predictive value for implantation and live birth outcomes.
trial registrationISRCTN85528745 (retrospectively registered on 30/01/2026).
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.