Risk factors and recurrence of hyperemesis gravidarum: A population-based record linkage cohort study

Sarah Pont; Diana M Bond; Antonia W Shand; Iqra Khan; Helga Zoega; Natasha Nassar

doi:10.1111/aogs.14966

Risk factors and recurrence of hyperemesis gravidarum: A population-based record linkage cohort study

Acta Obstet Gynecol Scand. 2024 Sep 11. doi: 10.1111/aogs.14966. Online ahead of print.

Authors

Sarah Pont^{1

2}, Diana M Bond^{1

2}, Antonia W Shand^{1

2

3}, Iqra Khan³, Helga Zoega^{4

5}, Natasha Nassar^{1

2

6}

Affiliations

¹ Child Population and Translational Health Research, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.
² Menzies Centre for Health Policy and Economics, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.
³ Royal Hospital for Women, Sydney, New South Wales, Australia.
⁴ School of Population Health, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia.
⁵ Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavík, Iceland.
⁶ Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia.

PMID: 39258527
DOI: 10.1111/aogs.14966

Abstract

Introduction: There are limited contemporary population-based studies on the risk factors for hyperemesis gravidarum (HG), a severe type of nausea and vomiting in pregnancy. This study aimed to determine the prevalence and trend of HG over time, identify risk factors for any and multiple HG health service visits during pregnancy, and investigate HG recurrence across pregnancies.

Material and methods: This population-based record linkage cohort study featured births in New South Wales, Australia from 2010 to 2019. Hospital and emergency data collections were used to identify health service visits for HG using relevant diagnosis codes and were linked to the corresponding pregnancy on the birth data set. Outcomes included any HG and multiple HG visits during pregnancy, and HG recurrence across pregnancies. Annual HG prevalence was calculated, and negative binomial regression was used to examine standardized prevalence trends. Risk factors for any HG and multiple HG visits within a pregnancy were examined using Robust Poisson models with generalized estimating equations and Prentice-Williams-Peterson Gap Time models, respectively. Rates and risk of recurrence were calculated for women with a second and third pregnancy.

Results: Of the 955 107 pregnancies, 21 702 (2.3%) were classified as HG. There was an average annual increase of 6.8% (95% CI 5.3-8.3) in HG prevalence. Younger maternal age, multiple pregnancies, and selected preexisting conditions were associated with an increased risk of HG, with the strongest factor being HG in any previous pregnancy (risk ratio 8.92, 99% CI 8.43-9.44). Hyperemesis gravidarum recurrence at the second (28.9%) and third (54.7%) pregnancies was high.

Conclusions: Hyperemesis gravidarum history is the strongest risk factor for HG, which has implications for counseling and care that women receive around pregnancy.

Keywords: cohort study; epidemiology; hyperemesis gravidarum; pregnancy complications.

Abstract

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