SOMANZ Poster Presentation Australasian Diabetes in Pregnancy Society and Society of Obstetric Medicine Australia and New Zealand Joint Scientific Meeting 2025

Exploring changing trends of preeclampsia in a local population of women with chronic hypertension (#193)

Madeleine M Cosgrave 1 2 , Catherine A Brumby 1 2 , Emily Schembri 2 , Lawrence P McMahon 1 2
  1. Department of Renal Medicine, Box Hill Hospital, Eastern Health , Melbourne, VIC, Australia
  2. Eastern Health Clinical School, Monash University , Melbourne, Vic , Australia

6870af1eb22c7-Figure+1.jpgBackground

Subjective observation has suggested rates of superimposed preeclampsia (PE) are increasing among women with chronic hypertension (CHTN) in our local population. This study aimed to characterise temporal trends in prevalence of PE and explore associations and risk factors.

Methods

We conducted a cohort study of pregnancies in women with CHTN at two obstetric centres in Melbourne between 2008-2024. Clinical data were collected on maternal demographics, BMI, previous PE, pre-existing diabetes or renal disease, anti-hypertensive use at conception, CHTN duration, secondary hypertension, and low-dose aspirin use. Temporal trends were explored and associations determined by regression analysis.

Results

Among 82,083 deliveries, 492 pregnancies were affected by CHTN. Annual prevalence rose 0.13% to 1.00% (trend p=0.015) over the study period. Superimposed PE incidence rose from 12.5% in 2008/09 to 23.26% in 2024 (p<0.001) (See Figure 1). No significant associations were observed with maternal age, BMI, parity, CHTN duration, assisted reproduction, comorbid conditions or booking BP. In contrast, the prevalence of chronic diabetes (0% to 4.65%, p=0.024) and aspirin use increased (0% to 87.12%, p<0.001). Rates of pre-term birth in women with PE remained stable, indicating the excess PE did not necessitate earlier delivery. Rates of special-care nursery admissions and small-for-gestational-age neonates were unchanged.

Conclusion

Pleasingly, aspirin use rose considerably after publication of the 2018 ASPRE trial. Reasons for increasing incidence of term preeclampsia are not elucidated in this study. This suggests other unmeasured factors, such as improving PE screening and diagnosis practices may be implicated, and are avenues for further research.