P22.09: Serial measurements of amniotic fluid volume in normal singleton pregnancies – an ongoing <scp>MRI</scp> and ultrasound study
Bibliographic record
Abstract
To describe amniotic fluid volume (AFV) longitudinally in normal singleton pregnancies. Prospective, longitudinal study of normal pregnancies examined every fourth week by magnetic resonance imaging (MRI) and ultrasound (US) from gestational week 16 until delivery. US measurements were single vertical deepest pocket (SVDP) from week 16 and additionally amniotic fluid index (AFI) from week 22. MRI was performed within 24 hours on a Siemens 1.5 Tesla system with a 3D high-resolution sequence covering the whole uterus. Sequence scan time was 14 seconds, repeated up to 20 times depending on fetal movement. Fetal volume and AFV excluding the umbilical cord were measured by manual segmentation of all MRI slices every 2 mm through the entire uterus in axial, coronal and sagittal planes using a threshold and filling technique in Mimics (Materialise, Belgium). Correlation between MRI and US measurements was calculated using Pearson's r. By April 2016, 12 participants have been included and five have completed the study. A total number of 52 MRI as well as US scans have been performed with AFI measured in 32 of the US scans. Fetal volumes by MRI showed growth curves with little variation and strong correlation to birth volumes calculated from birth weight (r = 0.94). AFVs by MRI showed volumes increasing up to 400–800 ml in second trimester. In third trimester, AFVs varied between 250–900 ml with individual patterns of AFV changes. We found a positive correlation between AFV and SVDP (r = 0.57) and between AFV and AFI (r = 0.47). Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
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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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".