Factors associated with the timing of the first prenatal ultrasound in Canada
Bibliographic record
Abstract
BACKGROUND: The aim of this study was to investigate the factors associated with the timing of the first prenatal ultrasound in Canada. METHODS: This was a secondary data analysis of the Maternity Experiences Survey, a cross-sectional survey covering different aspects of pregnancy, labour, birth and the post-partum period. Bivariate and multivariate multinomial logistic regressions were performed to assess the relationship between timing of first prenatal ultrasound and different independent variables. RESULTS: 68.4% of Canadian women received an optimally timed first prenatal ultrasound, 27.4% received early ultrasounds and 4.3% received late ultrasound. The highest prevalence of early ultrasound was in Ontario (33.3%) and the lowest was in Manitoba (13.3%). The highest prevalence of late ultrasound was found in Manitoba (12.1%) and the lowest was in British Columbia and Ontario (3.5% each). The highest prevalence of optimal timing of first prenatal ultrasound was in Quebec (77%) and the lowest was in Ontario (63.2%). Factors influencing the timing of ultrasound included: Early - maternal age < 20 (adjusted OR = 0.54, 95%CI:0.34-0.84), alcohol use during pregnancy (adjusted OR = 0.69, 95%CI:0.53-0.90), history of premature birth (adjusted OR = 1.41, 95%CI:1.06-1.89), multiparity (adjusted OR = 0.67, 95%CI:0.57-0.78), born outside of Canada (adjusted OR = 0.82, 95%CI:0.67-0.99), prenatal care in Newfoundland and Labrador (adjusted OR = 1.66, 95%CI:1.20-1.30), Nova Scotia (adjusted OR = 1.68, 95%CI:1.25-2.28), Ontario (adjusted OR = 2.16, 95%CI:1.76-2.65), Saskatchewan (adjusted OR = 1.50, 95%CI:1.05-2.14), Alberta (adjusted OR = 1.37, 95%CI:1.05-1.77) British Columbia (adjusted OR = 1.90, 95%CI:1.45-2.50) and Manitoba (adjusted OR = 0.66, 95%CI:0.45-0.98) Late - unintended pregnancy (adjusted OR = 1.89, 95%CI:1.38-2.59), born outside of Canada (adjusted OR = 1.75, 95%CI:1.14-2.68), prenatal care in Manitoba (adjusted OR = 2.88, 95%CI:1.64-5.05) and the Territories (adjusted OR = 4.50, 95%CI:2.27-8.93). An interaction between history of miscarriage and having 'other' prenatal care provider significantly affected timing of ultrasound (adjusted OR = 0.31, 95%CI:0.14-0.66). CONCLUSION: Only 68% of Canadian women received an optimally timed prenatal ultrasound which was influenced by several factors including province of prenatal care, maternal age and country of birth, and an interaction effect between prenatal care provider and history of miscarriage. These findings establish a baseline of factors influencing the timing of prenatal ultrasound in Canada, which can be built upon by future studies.
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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 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".