Association of housing tenure and unaffordable housing with preterm birth and other adverse birth outcomes in Canada: a population-based study.

Abstract

Background: Socioeconomic risk factors are known drivers of adverse birth outcomes. Housing is a key target for policy interventions.

Objective: To estimate the associations of housing tenure (renting vs owning) and unaffordable housing with preterm birth and other adverse birth outcomes.

Methods: We used 2014-2016 Canadian birth registration data linked with the 2016 long-form census and included singleton births among homeowners and renters. Unaffordable housing was defined at the family level as the proportion of pre-tax income spent on shelter, using a 30% cut-off. The primary outcome was preterm birth. Secondary outcomes were stillbirth and infant death. Log-binomial regression estimated the association of housing tenure and unaffordability with outcomes adjusting for sociodemographic risk factors and parity.

Results: Among 162 700 live births and stillbirths (52 740 renters, 109 960 owners), 31% of renters and 17% of owners experienced unaffordable housing. Renting was associated with an increased risk of preterm birth (7.5% vs 6.1%; adjusted risk ratio (aRR) 1.13; 95% CI 1.08 to 1.17), stillbirth (9.5 vs 6.6 per 1000; aRR 1.33, 95% CI 1.14 to 1.56) and infant death (4.2 vs 3.0 per 1000; aRR 1.52, 95% CI 1.26 to 1.82). There was no association of housing unaffordability with preterm birth or other adverse birth outcomes among owners or renters.

Conclusions: This nationally representative study in Canada found associations between renting versus owning and preterm birth, stillbirth and infant death, as well as a high burden of unaffordable housing, particularly among renters. This study suggests that home tenure itself is a social determinant of adverse birth outcomes.