Impact of the global financial crisis on low birth weight in Portugal: a time-trend analysis

Background: The 2007-2008 global financial crisis had adverse consequences on population health of affected European countries. Few contemporary studies have studied its effect on perinatal indicators with long-lasting influence on adult health. Therefore, in this study, we investigated the impact of the 2007-2008 global financial crisis on low birth weight (LBW) in Portugal. Methods: Data on 2 045 155 singleton births of 1995-2014 were obtained from Statistics Portugal. Joinpoint regression analysis was performed to identify the years in which changes in LBW trends occurred, and to estimate the annual per cent changes (APC). LBW risk by time period expressed as prevalence ratios were computed using the Poisson regression. Contextual changes in sociodemographic and economic factors were provided by their trends. Results: The joinpoint analysis identified 3 distinct periods (2 jointpoints) with different APC in LBW, corresponding to 1995-1999 (APC=4.4; 95% CI 3.2 to 5.6), 2000-2006 (APC=0.1; 95% CI -050 to 0.7) and 2007-2014 (APC=1.6; 95% CI 1.2 to 2.0). For non-Portuguese, it was, respectively, 1995-1999 (APC=1.4; 95% CI -3.9 to 7.0%), 2000-2007 (APC=-4.2; 95% CI -6.4 to -2.0) and 2008-2014 (APC=3.1; 95% CI 0.8 to 5.5). Compared with 1995-1999, all specific maternal characteristics had a 10-15% increase in LBW risk in 2000-2006 and a 20-25% increase in 2007-2014, except among migrants, for which LBW risk remained lower than in 1995-1999 but increased after the crisis. The increasing LBW risk coincides with a deceleration in gross domestic product growth rate, reduction in health expenditure, social protection allocation on family/children support and sickness. Conclusions: The 2007-2008 global financial crisis was associated with a significant increase in LBW, particularly among infants of non-Portuguese mothers. We recommend strengthening social policies aimed at maternity protection for vulnerable mothers and health system maintenance of social equity in perinatal healthcare.