Trends in cardiometabolic conditions and pregnancy outcomes: a retrospective cohort study in South-Eastern Melbourne

OBJECTIVES: To examine trends in preconception and pregnancy cardiometabolic risk factors and conditions, pregnancy and birth complications, obstetric interventions, and the impact of COVID-19, and to forecast future disease burden. DESIGN: A multi-centre retrospective cohort study. SETTING: A large hospital network with three maternity hospitals serving ethnically diverse populations in Melbourne, Australia. PARTICIPANTS: Pregnant women who gave birth between 2016 and 2022. OUTCOME MEASURES: Trends in cardiometabolic conditions, birth complications and obstetric interventions. RESULTS: Over 7 years, 63 232 women were included, of whom 40% were nulliparous, and 60.9% were born overseas from 167 countries. From 2016-2022, maternal age (30.2-31.3 years), obesity (21.0%-26.2%), gestational diabetes mellitus (GDM) (15.9%-28.1%) and caesarean delivery (28.5%-37.6%) increased, while average gestational weight gain, premature births and special care admissions declined from 12.6-11.6 kg, 6.3%-4.9% and 24.2%-14.1%, respectively; and was statistically significant (p<0.05). Hypertensive disorders of pregnancy remained stable, fluctuating slightly (6.5% in 2016, 7.6% in 2020, 6.9% in 2022). During the COVID-19 lockdown period, the odds of GDM and induced birth increased by 8.0%, whereas the odds of caesarean section decreased by 5.0%. GDM is forecast to reach 43.0% by 2028. CONCLUSIONS: Prepregnancy and pregnancy cardiometabolic risk factors and conditions, pregnancy and birth complications, and obstetric interventions increased markedly over 7 years. Despite this, offspring complications, including special care admissions, stillbirths and prematurity, decreased, while pregnancy complications peaked during COVID-19. GDM is forecasted to increase to 43.0% by 2028, posing an unsustainable health and economic burden that necessitates urgent public health initiatives.