Analysis of preventability of hypertensive disorder in pregnancy-related maternal death using the nationwide registration system of maternal deaths in Japan

Objective: Hypertensive disorder of pregnancy (HDP) is a major cause of maternal death. The goal of this study was to investigate factors associated with maternal death due to HDP. Study design: HDP-related maternal deaths in Japan reported to the Committee of the Ministry of Health, Labor and Welfare from 2010 to 2015 were examined. Results: Out of 47 cases of HDP, 30 were identified as the major cause of maternal death. The median maternal age was 34 years (range 24–45) and the mortality in women aged ≥40 years was seven times higher that than in women aged <34 years. The etiologies were intracerebral hemorrhage (n = 22), subarachnoid hemorrhage (n = 3), subcapsular hematoma of the liver (n = 2), peripartum cardiomyopathy (n = 2), and eclampsia (n = 1), and 19 cases were deemed preventable. The most frequent antepartum problems were delays in hospitalization, maternal transfer, and termination of pregnancy. In four cases, diagnosis of HELLP syndrome was too late because laboratory data were not checked, despite the patient reporting epigastric pain or showing elevation of blood pressure (BP). Treatment for lowering of BP was improper in 2/3 intrapartum cases, even though BP was elevated during pregnancy (144 versus 188 mmHg, p <.001). There was inadequate lowering of BP and lack of use of magnesium sulfate in 7/11 postpartum cases (64%), despite aspartate aminotransferase (AST) (p <.005), alanine aminotransferase (ALT) (p <.01), lactate dehydrogenase (LDH) (p <.005), and platelet count (PLT) (p <.01) all significantly worsening after delivery. Conclusion: HDP accounts for 11% of maternal deaths in Japan. Mothers aged ≥40 years are most at risk for HDP-related maternal death. Major concerns for preventabilities were late hospitalization, maternal transportation, and termination of pregnancy for term or near-term HDP. Regular vital checks and prompt lowering of BP were lacked during labor in most cases. HELLP syndrome should be managed at a general hospital with sufficient medical resources.