Birth weight differences between preterm stillbirths and live births: analysis of population-based studies from the U.S. and Sweden
Bibliographic record
Abstract
BACKGROUND: Many stillbirths show evidence of fetal growth restriction, and most occur at preterm gestational age. The objective of this study is to compare birth weights at preterm gestational ages between live births and stillbirths, and between those occurring before or during labour. METHODS: Based on singleton births from the United States (U.S.) 2003-2005 (n=902,491) and Sweden 1992-2001 (n=946,343), we compared birth weights between singleton live births and stillbirths at 24-36 completed weeks of gestation from the U.S. and at 28-42 completed weeks from Sweden. RESULTS: In both the U.S. and Sweden, stillbirth weight-for-gestational-age z-scores were at least one standard deviation lower than live birth z-scores at all preterm gestational ages (GA). In Sweden, no birth weight difference was observed between antepartum and intrapartum stillbirths at preterm GAs, whereas birth weights among intrapartum stillbirths were similar to those among live births at 37-42 weeks. CONCLUSIONS: Birth weights observed at preterm gestation are abnormal, but preterm stillbirths appear to be more growth-restricted than preterm live birth. Similar birth weights among ante- and intrapartum preterm stillbirths suggest serious fetal compromise before the onset of labor.
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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 | 0.006 | 0.014 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.005 | 0.006 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".