Maternal Vitamin B12 Levels During Pregnancy and Their Effects on Maternal Neurocognitive Symptoms: A Systematic Review
Bibliographic record
Abstract
Background Vitamin B12 deficiency has been linked to neurocognitive symptoms. Vitamin B12 deficiency in pregnancy may be associated with antenatal or postpartum depression along with other neurocognitive symptoms including restless leg syndrome. Objectives: To systematically review the literature regarding vitamin B12 deficiency and insufficiency in pregnancy and effects on the maternal neurocognitive state. Search Strategy: Medline, Embase, and SCOPUS were searched from inception to October, 2020. Selection Criteria: Reports on vitamin B12 deficiency in pregnancy were searched. Data Collection and Analysis: Data were synthesized and presented narratively. Main Results: The five studies included in the analysis did not demonstrate a statistically significant link between vitamin B12 deficiency or insufficiency and either restless leg syndrome or depression in pregnancy. Conclusions: To date, evidence is lacking that would support a causal link between suboptimal vitamin B12 serum levels and maternal restless leg syndrome or depression.
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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 | 0.003 | 0.015 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.006 | 0.005 |
| Bibliometrics | 0.006 | 0.008 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".