Pregnancy-related hospitalisation among women who inject drugs in Melbourne, Australia

Background 

Pregnancy outcomes and terminations of pregnancy among women who inject drugs are poorly understood. We aim to describe pregnancy-related hospitalisations and terminations of pregnancy, and estimate birth and fertility rates among a cohort of Australian women who inject drugs.  

Methods 

Women from the SuperMIX study, a prospective cohort of people who inject drugs who reside in Victoria, Australia, were linked to hospitalisation records from 2008–2019. International Classification of Diseases, 10th edition (ICD-10) codes for pregnancy, childbirth, and the puerperium were identified in data from Victorian hospitals. Outcomes of interest were pregnancy terminations, births, and complications in birth. Average fertility (average number of children per woman) and average birth (number of births per 1000 person years [PY]) rates were calculated for women and compared to rates among Australian women in the general population of reproductive age (15–44 years), 2008–2019.  

Results 

In total, 424 (32% of SuperMIX sample) women were included, of which 228 (53.8%) experienced a pregnancy or childbirth-related hospitalisation. Hospitalisation records indicated 284 terminations of pregnancy among 136 women, 231 live births among 151 women, and 173 women experienced complications during labour and delivery of a baby (76% of all women who recorded a pregnancy-related hospitalisation). For all births, the mean age of mothers was 30 years. Across the study period, the average fertility rate was 0.5, compared to 1.8 in the general population. The average birth rate was 54/1000 PYs, compared to 62/1000 women in the general population.  

Conclusion 

Most births in Australia occur in hospitals; in 2021 59% of Australian women who gave birth in hospital had a stay of less than one day (indicating a routine birth). Thus, this data suggests women in SuperMIX experienced a high burden of birth complications. The frequency of complications observed is in the context of universal healthcare in Australia, with free or low-cost antenatal care. This study raises substantial concern about the maternal health experiences of women who inject drugs, with further research needed to understand the primary and preventative care women who inject drugs want and need.