Regional Birth Outcomes after the 2011 Great East Japan Earthquake and Tsunami in Miyagi Prefecture

Objectives: This study was aimed to analyze post-disaster birth outcomes in coastal and inland regions of Miyagi Prefecture, Japan. Methods: Primary data sets were compiled from birth records of obstetric facilities and 12,808 patients were analyzed for baseline birth outcomes by region. Regional risk analysis of the low-birth-weight rate and premature birth rate were conducted using multi-level logistic regression analysis. Results: From overall baseline birth outcomes, a preterm birth rate was 4.6% and low-birth-weight rate was 8.8%. Regional analysis revealed that a preterm birth rate was 3.2% (coastal) and 5.0% (inland), respectively, and the rate of low birth weight was 6.5% in the coastal and 8.5% in the inland region. In the risk analysis of low-birth-weight rate and preterm birth rate, the risk in the coastal region could not be considered any higher than in the inland region (adjusted odds ratio 0.91 [0.73-1.14] and 0.85 [0.46-1.59], respectively). Conclusions: The incidence of preterm birth and low birth weight were not adversely affected by the disaster. Early transfer and intensive medical intervention may have led to those findings. Further survey will be necessary to determine the long-term effects in both mothers and children.