Severe mental illness and pregnancy outcomes in Australia. A population-based study of 595 792 singleton births 2009–2016

BACKGROUND: Women with Severe Mental Illness (SMI) may have more complex pregnancies and pregnancy outcomes that require different care and management, but this has not been extensively studied. The aim of this study was to explore associations between SMI and adverse maternal and infant outcomes in the state of Victoria, Australia. METHODS: Our sample included all reported live singleton births in Victoria 2009-2016 (N = 595 792). Associations between SMI and adverse pregnancy outcomes were explored using Odds Ratios (OR), adjusted for sociodemographic and lifestyle factors, and co-morbidities, including any other mental illness. RESULTS: Of all singleton births, 2046 (0.34%) were to a mother diagnosed with a SMI. We found evidence of an association between SMI and a range of adverse maternal and infant outcomes. Compared to women without SMI, women with a SMI had higher adjusted odds of being admitted to a High Dependency Unit or Intensive Care Unit (aOR 1.83, 1.37-2.43), having gestational diabetes mellitus (1.57, 1.34-1.84), undergoing an unplanned caesarean section (1.17, 1.02-1.33), induction of labour (1.17, 1.05-1.30) and postpartum haemorrhage (1.15, 1.03-1.29). Newborns of women with SMI had higher adjusted odds of being admitted to Special Care Nursery (aOR 1.61, 1.43-1.80), a low Apgar score at 5 minutes (1.50, 1.19-1.90), preterm birth (1.40, 1.20-1.63), and low birthweight (1.26, 1.06-1.49). CONCLUSION: Women with SMI are at higher risk for a range of adverse maternal and infant outcomes and are a population that may benefit from targeted early identification and enhanced antenatal care.