The effect of the Great East Japan Earthquake on hypertensive disorders during pregnancy: a study from the Fukushima Health Management Survey

Objectives: This study aimed to assess the effects of the Great East Japan Earthquake on hypertensive disorder of pregnancy (HDP) in the Fukushima Prefecture.Methods: We used the results of the Fukushima Health Management Survey which targeted women who gave birth from 2011-2012. Pregnant women were divided into three groups according to their residential area during the disaster (affected, middle, and less-affected area), and four groups according to pregnancy trimester during the disaster (first, second, third trimester, or conception after the disaster). Adjusted odds ratio (aORs) for HDP of each residential area was calculated using logistic regression models, with pregnancy trimester during the disaster as references.Results: Overall, 8323 women participated in the study (affected area: 2207; middle area: 5183; and less-affected area: 933). For women living in the affected and middle areas in the third trimester, the disaster was a significant risk factor for HDP (aOR: 2.61, 1.02-6.66, aOR: 1.93, 1.10-3.40, respectively).Conclusions: To our knowledge, this is the first study to integrate patient residential areas and gestational age during the time of a disaster to estimate the risk of HDP. The third trimester of pregnancy at the time of the disaster was associated with HDP for the women living in the affected and middle areas. The knowledge of the data on disaster-related obstetrical complications can help obstetric care providers in a disaster area provide appropriate medical aid in an emergency.