Adverse Pregnancy Outcomes and Chronic Hypertension in the Era of Prevention: A Contemporary, Retrospective Cohort Study Using Data from the National Inpatient Sample Database
Bibliographic record
Abstract
Abstract Chronic hypertension is a known risk factor for the development of preeclampsia and obstetrical morbidity. However, recent risk estimates, particularly in the era of use of low-dose acetylsalicylic acid for preeclampsia prevention, are lacking. This study aimed to estimate the association between chronic hypertension and preeclampsia and other adverse pregnancy outcomes in a contemporary cohort of births spanning the period, since the introduction of a low-dose acetylsalicylic acid protocol. The secondary outcome was to estimate trends in preeclampsia and preterm birth among patients with chronic hypertension during the study period. A retrospective, population-based cohort study was conducted using the National Inpatient Sample Database to identify individuals discharged from hospitals in the United States following obstetrical delivery from 2014 to 2019. Pregnancies complicated by chronic hypertension were identified using ICD 9/10 (International Classification of Diseases 9th and 10th editions) codes. Multivariable logistic regression models were used to estimate the adjusted odds ratios for the association between chronic hypertension and adverse pregnancy outcomes compared with pregnancies not complicated by chronic hypertension. Temporal trends in preeclampsia and preterm birth among patients with chronic hypertension were estimated over the study period. Among 4,451,667 obstetrical delivery-related admissions, 139,556 (3.1%) included pregnancies complicated by chronic hypertension. Of these, 27,146 (19.4%) admissions included pregnancies with superimposed preeclampsia, compared with 222,351 (5.2%) of admissions that included pregnancies with preeclampsia without prior diagnosis of chronic hypertension. Pregnancies complicated by chronic hypertension were associated with 3.29 times the odds of preeclampsia compared with pregnancies without chronic hypertension (95% confidence interval: 3.22–3.36), but the odds of preeclampsia (p-value for linear trend <0.0001) and preterm birth (p-value for linear trend = 0.0001) in this subgroup decreased over the study period. While the odds of preeclampsia are increased among pregnancies complicated by chronic hypertension, the odds of preeclampsia in this population have decreased over time.
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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 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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".