432Recurrent stillbirth: a population-based study from South Australia

Abstract

Abstract Background In high-income countries, stillbirth is a relatively rare event occurring in < 1% of pregnancies. Recurrent stillbirth is even rarer. Our objective was to explore the prevalence of stillbirth and recurrent stillbirth, factors associated with stillbirth and whether a stillbirth in first pregnancy influences the time to subsequent pregnancy. Methods This population-based study involved routinely-collected administrative data on singleton births in South Australia from 1998 to 2015 (n = 333,785). Stillbirth was defined as pregnancies >20 weeks gestation or weighing >400 grams. Univariable and multivariable logistic regression was used to explore associations between sociodemographic factors and stillbirth. Cox proportional hazard was used to explore time to pregnancy. Results 0.7% of all first pregnancies and 0.6% of all second pregnancies were stillbirths. Of women in their second pregnancy, <10 experienced recurrent stillbirth. In univariable analyses, higher odds of stillbirth in second pregnancies were associated with younger and older maternal age (<20 or ≥ 40 years), being single, unemployed, smoking, shorter inter-pregnancy intervals and numerous medical conditions (e.g. diabetes or hypertension). Multivariable models were unstable due to too few data. The hazard ratio for women who previously experienced a stillbirth compared with livebirth was 1.14 (95%CI 0.39, 3.32). Conclusions Studying recurrent stillbirth is especially difficult due to the rare nature of the problem, limiting progress on developing evidence-based advice for women who experience stillbirth in their first pregnancy. Key messages Recurrent stillbirth is challenging to study due to the rareness of the problem but could be addressed by careful pooling of large administrative datasets.