Effect of medical institution change on gestational duration after the Great East Japan Earthquake: The Fukushima Health Management Survey

Aim The aim of this study was to examine the association between medical institution change for perinatal care and gestational duration after the Great East Japan Earthquake using data from the Fukushima Health Management Survey. Methods The data of pregnant women who experienced the earthquake in Fukushima prefecture and participated in the Pregnancy and Birth Survey as part of the Fukushima Health Management Survey were analyzed. The primary and secondary outcomes of this study were gestational duration and preterm birth, respectively. The main study factor was prenatal checkup institution (only one institution, changed institution due to self‐referral, changed institution due to medical indication, and went to parents' home for childbirth). Self‐referral was considered as indicative of relocation after the disaster. Multiple linear and logistic regression analyses were conducted to examine the effect of earthquake on each outcome. Results A total of 5593 (60.2%) participants experienced the earthquake between the 4th and 37th weeks of their gestational period. After controlling for variables, pregnant women who changed their perinatal checkup institution due to medical indication were significantly associated with shorter gestational duration (β = −10.6, P