Objective: Public Health initiatives, such as the "Safe to Sleep" campaign, have traditionally targeted infants' risk factors for the prevention of Sudden Infant Death Syndrome (SIDS). However, controversy remains regarding maternal and obstetrical risk factors for SIDS. In our study, we sought out to determine both modifiable and non-modifiable obstetrical and maternal risk factors associated with SIDS.
Methods: We conducted a population-based cohort study using the CDC's Linked Birth-Infant Death data from the United States for the year 2010. The impact of several obstetrical and maternal risk factors on the risk of overall infant mortality and SIDS was estimated using unconditional regression analysis, adjusting for relevant confounders.
Results: Our cohort consisted of 4,007,105 deliveries and 24,174 infant deaths during the first year of life, of which 1991 (8.2%) were due to SIDS. Prominent risk factors for SIDS included (OR [95% CI]): black race, 1.89 [1.68-2.13]; maternal smoking, 3.56 [3.18-3.99]; maternal chronic hypertension, 1.73 [1.21-2.48]; gestational hypertension, 1.51 [1.23-1.87]; premature birth <37 weeks, 2.16 [1.82-2.55]; IUGR, 2.46 [2.14-2.82]; and being a twin, 1.81 [1.43-2.29], p < 0.0001. Relative to a cohort of infants who died of other causes, risk factors with a predilection for SIDS were maternal smoking, 2.48 [2.16-2.83] and being a twin, 1.52 [1.21-1.91], p < 0.0001. Conclusions for practice: While certain socio-demographic and gestational characteristics are important risk factors, maternal smoking remains the strongest prenatal modifiable risk factor for SIDS. We recommend the continuation of Public Health initiatives that promote safe infant sleeping practices and smoking cessation during and after pregnancy.
Keywords: Sudden infant death syndrome; infant mortality; maternal causes; risk factors.