(883) Hypertension in pregnancy without a documented diagnosis: a missed window of opportunity

Obstetric patients with chronic hypertension (HTN) and hypertensive disorders of pregnancy (HDP) may not receive corresponding ICD-10 codes due to missed diagnoses or documentation errors. We aimed to compare (1) healthcare engagement at 6 weeks postpartum (PP) and (2) American College of Cardiology (ACC) HTN staging at 6 months PP between hypertensive patients with and without corresponding ICD-10 codes.

Study Design:

This was a retrospective study of patients delivering within a healthcare system from 2013-2023 with ≥1 prenatal visit. Exclusion criteria were < 2 recorded blood pressures (BPs) at < 20 weeks’ gestation and no evidence of elevated BPs or cHTN/HDP by ICD-10 code. The electronic medical record was used to identify patients with HTN; these were then classified as “BP only” (≥2 BPs of ≥140/90 mmHg at < 20 weeks and/or 20 weeks to delivery discharge without an ICD-10 code for cHTN/HDP) or “ICD-10” (with an ICD-10 code for cHTN/HDP). Demographic characteristics and ACC HTN stages at 6 months were compared between groups using chi-square tests. The primary outcomes - attendance at any PP visit or HTN-focused visit within 6 weeks PP - were compared using multivariate logistic regression, adjusted for significant covariates.

Results:

Of 21,296 patients, 9,833 (46.2%) were identified as BP only and 11,463 (53.8%) as ICD-10. Compared to the BP only group, the ICD-10 group was significantly more likely to attend any PP visit [80.1% vs. 65.6%; aOR 2.0 (95% CI 1.8-2.1)] or PP HTN-focused visit [36.4% vs. 2.5%; aOR 17.3 (95% CI 15.1-19.8)]. Both BP only and ICD-10 patients demonstrated elevated BP by ACC staging at 6 months PP: elevated (13.1% vs 13.3%), Stage 1 (14.7% vs 22.6%), and Stage 2 (2.3% vs 9.4%).

Conclusion: Elevated BP in pregnancy in the absence of an associated ICD-10 diagnosis code is associated with lower healthcare engagement up to 6 weeks PP. Despite this, patients with elevated BPs without an ICD-10 diagnosis of cHTN or HDP remain at risk for ongoing BP elevation for at least 6 months from delivery, highlighting a need for improved recognition and documentation of antenatal HTN.