ImportanceThe 1980 and 1986 Swedish so-called speed premium policies aimed at protecting parents’ income-based parental leave benefits for birth intervals shorter than 24 and 30 months, respectively, but indirectly encouraged shorter birth spacing and childbearing at older ages, both risk factors for several perinatal health outcomes. Whether those policy changes are associated with perinatal health remains unknown.ObjectiveTo evaluate the association between the 1980 and 1986 speed premium policies and perinatal health outcomes.Design, Setting, and ParticipantsThis cross-sectional study investigated data from 1 762 784 singleton births in the Swedish Medical Birth Register from January 1, 1974, through December 31, 1991. Data were analyzed from October 11, 2022, to December 12, 2023.InterventionsSpeed premium policy introduction (January 1, 1980) and extension (January 1, 1986).Main Outcomes and MeasuresTotal population register data were used in an interrupted time series analysis with segmented logistic regression to calculate the odds of preterm birth, low birth weight, small for gestational age (SGA) at preterm, and stillbirth measured before and after the speed premium policy reforms. Subgroup analyses by maternal origin were conducted to evaluate changes by different policy responses.ResultsAmong 1 762 784 births analyzed, 4.8% were preterm (of which 12.0% were SGA), 3.2% had low birth weight, and 0.3% were stillbirths. The 1980 speed premium policy was associated with a 0.3% monthly increase in the odds of preterm birth compared with the period before the reform (odds ratio [OR], 1.0029 [95% CI, 1.002-1.004]), equivalent to a 26.4% increase from January 1, 1980, to December 31, 1985. After the 1986 relaxation of the policy, preterm birth odds decreased 0.5% per month (OR, 0.9951 [95% CI, 0.994-0.996]), equivalent to an 11.1% decrease across the next 6 years. Low birth weight displayed a similar pattern for both reform periods, that is, increased 0.2% (OR, 1.0021; 95% CI, 1.001-1.003) per month in 1980 through 1985 compared with baseline, and decreased 0.3% (OR, 0.9975; 95% CI, 0.996-0.998) per month in the following period, but was attenuated when considering low birth weight at term. Odds of SGA at preterm were decreased after 1980 (OR, 0.9965; 95% CI, 0.994-0.999) but not in 1986 (OR, 1.0009; 95% CI, 0.998-1.003), whereas stillbirths did not change following either reform (1980: OR, 1.0020 [95% CI, 0.999-1.005]; 1986: OR, 1.0002 [95% CI, 0.997-1.003]). Subgroup analyses suggested that perinatal health changes were restricted to births to Swedish- and Nordic-born mothers, the primary groups to adjust their fertility behaviors to the reforms.Conclusions and RelevanceDespite its economic advantages for couples, especially for mothers, the introduction of the speed premium policy was associated with 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 repercussions for fertility behaviors and, in turn, perinatal health.

中文翻译：

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与瑞典家庭政策相关的意外围产期健康后果

重要性 1980 年和 1986 年瑞典所谓的速度保费政策旨在分别保护出生间隔短于 24 个月和 30 个月的父母的基于收入的育儿假福利，但间接鼓励了较短的出生间隔和高龄生育，这两个风险因素一些围产期健康结果。这些政策变化是否与围产期健康相关仍然未知。目的评估 1980 年和 1986 年的快速保费政策与围产期健康结果之间的关联。设计、设置和参与者这项横断面研究调查了瑞典 1 762 784 名单胎出生的数据。 1974年1月1日至1991年12月31日的医疗出生登记。数据分析时间为2022年10月11日至2023年12月12日。干预措施加快保费政策推出（1980年1月1日）和延期（1986年1月1日）。主要结果和措施总人口登记数据用于分段逻辑回归的中断时间序列分析，以计算速度保费政策前后测量的早产、低出生体重、早产胎龄 (SGA) 和死产的几率改革。按产妇来源进行亚组分析，以评估不同政策反应带来的变化。结果在分析的 1 762 784 名新生儿中，4.8% 为早产（其中 12.0% 为 SGA），3.2% 为低出生体重，0.3% 为死产。与改革前相比，1980 年的速度保费政策导致早产几率每月增加 0.3%（优势比 [OR]，1.0029 [95% CI，1.002-1.004]），相当于 26.4%从1980年1月1日到1985年12月31日增加。1986年放宽政策后，早产几率每月下降0.5%（OR，0.9951 [95% CI，0.994-0.996]），相当于下降11.1%跨越未来6年。低出生体重在两个改革时期都表现出类似的模式，即 1980 年至 1985 年，与基线相比每月增加 0.2%（OR，1.0021；95% CI，1.001-1.003），并下降 0.3%（OR，0.9975；95% CI，1.001-1.003）。 95% CI, 0.996-0.998）在接下来的时期每月，但当考虑到足月出生体重低时，该值减弱。 1980 年之后，早产儿 SGA 的几率有所下降（OR，0.9965；95% CI，0.994-0.999），但 1986 年没有变化（OR，1.0009；95% CI，0.998-1.003），而死产率在两次改革后都没有变化（1980 年）。 ：OR，1.0020 [95% CI，0.999-1.005]；1986 年：OR，1.0002 [95% CI，0.997-1.003]）。亚组分析表明，围产期健康变化仅限于瑞典和北欧出生的母亲的生育，这是根据改革调整生育行为的主要群体。结论和相关性尽管速度的引入对夫妇，特别是对母亲来说有经济优势，保费政策与不良的围产期健康后果有关，特别是对于早产。家庭政策应以“所有政策中的健康”为视角精心设计，以避免对生育行为以及围产期健康可能产生意想不到的影响。