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

Hyperemesis gravidarum and risk of long-term maternal hospitalisations: a population-based study in NSW (128382)

Diana M Bond 1 2 , Sarah Pont 1 2 , Antonia W Shand 1 2 3 , Laura Gerhardy 1 2 4 , Claudia Bruno 1 2 , Natasha Nassar 1 2 5
  1. Child Population and Translational Health Research, Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
  2. Leeder Centre for Health Policy, Economics, and Data, University of Sydney, Sydney, NSW, Australia
  3. Maternal Fetal Medicine, Royal Hospital for Women, Randwick, NSW, Australia
  4. Maternal Fetal Medicine, Nepean Hospital, Penrith, NSW, Australia
  5. Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia

Background: Hyperemesis gravidarum (HG), characterised by severe and constant nausea and vomiting in pregnancy is associated with adverse pregnancy outcomes, with limited research on long-term maternal morbidity. This study aimed to determine whether exposure to HG during pregnancy was associated with maternal morbidity beyond the postpartum period.

Methods: This population-based record linkage study included all births among women in New South Wales with a first recorded birth between 2006–2018. Maternal HG was classified using hospital admissions and emergency department presentations during pregnancy. Outcomes included all-cause hospitalisations at least six weeks post-birth. Association between HG exposure and subsequent hospitalisations was examined using Prentice-Williams-Peterson total time models, stratified by birth order and accounting for repeated measures per individual. Models were adjusted for sociodemographic, pregnancy and birth factors, and health service utilisation during and prior to pregnancy.

Results: Among 875,788 births (to 508,806 women), 18,046 (2.1%) were exposed to HG. Incidence rate of post-birth hospitalisations was higher for HG-exposed births with 311.3 (95% CI 306.7–315.9) per 1,000 person-years compared to 183.9 (95% CI 183.4–184.4) per 1,000 person-years for non-exposed births. After adjusting for covariates, births exposed to HG were associated with an increased risk of any post-birth hospitalisation (aHR 1.18, 95% CI 1.15–1.21).

Conclusion: Women with HG had slightly higher long-term risk of hospitalisations, even after adjusting for prior health service utilisation. Further exploration of reasons for hospitalisation and potential management considerations will be presented.