Levothyroxine Dosage Requirement During Pregnancy in Well-Controlled Hypothyroid Women: A Longitudinal Study
Bibliographic record
Abstract
BACKGROUND: Untreated maternal hypothyroidism can have adverse effects on both the mother and fetus, but it can potentially be prevented by adequate levothyroxine replacement. This study was conducted to determine what percentage of hypothyroid pregnant women who were taking levothyroxine needed to adjust their medication dosage, and when and how much it should be increased. METHODS: In this longitudinal study, 81 well-controlled hypothyroid women (TSH≤ 2.5 mIU/L) were monitored throughout pregnancy. Thyroid function tests were performed before conception, after the first missed menstrual period, in the second and third trimesters of pregnancy and one month after delivery. Levothyroxine dosage was adjusted according to TSH levels measured. RESULTS: Of the 81 pregnancies studied, the pregnancy outcomes were 74 full-term births, six abortions and one pre-term birth. The levothyroxine dosage needed to be increased in 84% (CI95%= 74-90) of the pregnancies (OR=5.2, CI95%= 2.9-9.4). Most levothyroxine dose adjustments were made in the first trimester of gestation. The levothyroxine requirement increased 50% (CI95%= 41-59) in the first trimester, 55% (CI95%= 45-64) in the second trimester and 62% (CI95%= 52-72) in the third trimester. Levothyroxine dosage was decreased for 6 cases (7.4%), and no adjustment was made for 7 women (8.6%). CONCLUSIONS: Increases in levothyroxine dosage administered in pregnancy appear to be indispensible in the majority of patients with well-controlled hypothyroidism, especially in the first trimester. However, this change was not universal and levothyroxine dosage decreased in a few cases and remained unchanged in others.
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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 | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 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 | 0.001 |
| 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".