Unintended perinatal health consequences of a Swedish family policy: A population-based study

BACKGROUND: Family policies can influence parents’ fertility behaviors, with consequences for perinatal health. The 1980 and 1986 Swedish speed premium policies aimed to protect parents’ income-based parental leave benefits within birth intervals shorter than 24 and 30 months, respectively, but additionally encouraged shorter birth spacing and childbearing at older ages - both risk factors for several perinatal health outcomes. This study evaluates the association of the 1980 and 1986 speed premium policies with perinatal health outcomes. METHODS: We used information on all singleton births in Sweden from 1974 to 1991 (n = 1,762,784) to calculate rates of preterm birth, low birthweight (LBW), small for gestational age (SGA) at preterm and stillbirth, by month and year of birth. Changes in outcomes at reform periods were evaluated with interrupted time series analyses. RESULTS: The 1980 speed premium policy was linked to a monthly rate increase in preterm births relative to the pre-reform period (0.013 [95% CI 0.0061-0.0200] percentage points), equivalent to a 24% increase from 1980 to 1986. After the 1986 relaxation of the policy, the trend in monthly rates reversed (-0.025 [95% CI -0.033--0.018] percentage points). LBW displayed a similar pattern over both reform periods, which was attenuated when considering LBW at term. Rates of SGA at preterm and stillbirths did not change following either reform. Further analyses suggested that changes in perinatal health were restricted to births among native- and Nordic-born mothers, i.e., the primary groups to adjust their fertility behaviors to the reforms. CONCLUSIONS: Despite its economic advantages for couples, especially mothers, the introduction of the speed premium policy had adverse perinatal health consequences particularly for preterm births. Family policies should be carefully designed with a ‘Health in All Policies’ lens to avoid possible unintended adverse repercussions for perinatal health. KEY MESSAGES: • Family policies can have unintended, adverse perinatal health effects if their eligibility requirements encourage individuals to make fertility decisions that are associated with health risks. • Policymakers should adopt a ‘Health in All Policies’ approach for developing and evaluating family policies to avoid unintended public health harms.