The Human Fetus Preferentially Secretes Corticosterone, Rather than Cortisol, in Response to Intra-Partum Stressors
Bibliographic record
Abstract
CONTEXT: Fetal stress is relevant to newborn outcomes. Corticosterone is rarely quantified in human clinical endocrinology and is found at much lower concentrations than cortisol. However, fetal corticosterone is a candidate hormone as a fetal stress signal. OBJECTIVE: Test the hypothesis that preferential fetal corticosterone synthesis occurs in response to fetal intra-partum stress. DESIGN: Cross-sectional comparison of paired serum corticosteroid concentrations in umbilical artery and vein from 300 women providing consent at admission to a General Hospital Labor and Delivery unit. Pre-term and multiple births were excluded, leaving 265 healthy deliveries. MAIN OUTCOME MEASURES: Corticosterone and cortisol concentrations determined by LC-MS/MS for umbilical cord venous (V) and arterial (A) samples and used to calculate fetal synthesis (A-V) and proportional fetal synthesis ([A-V]/V). Chart-derived criteria stratified samples by type of delivery, maternal regional analgesia, augmentation of contractions, and clinical rationale for emergent Caesarian delivery. RESULTS: Cortisol concentrations were higher than corticosterone concentrations; however, the fetus preferentially secretes corticosterone (148% vs 49% proportional increase for cortisol) and differentially secretes corticosterone as fetal stress increases. Fetal corticosterone synthesis is elevated after passage through the birth canal relative to Caesarian deliveries. For vaginal deliveries, augmentation of contractions does not affect corticosteroid concentrations whereas maternal regional analgesia decreases venous (maternal) concentrations and increases fetal synthesis. Fetal corticosterone synthesis is also elevated after C-section indicated by cephalopelvic disproportion after labor, whereas cortisol is not. CONCLUSIONS: The full-term fetus preferentially secretes corticosterone in response to fetal stress during delivery. Fetal corticosterone could serve as a biomarker of fetal stress.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".