Characteristics of Maternal Mortality Missed by Vital Statistics in Hong Kong, 2000-2019

Abstract

ImportanceReducing maternal mortality is a global objective. The maternal mortality ratio (MMR) is low in Hong Kong, China, but there has been no local confidential enquiry into maternal death, and underreporting is likely.ObjectiveTo determine the causes and timing of maternal death in Hong Kong and identify deaths and their causes that were missed by the Hong Kong vital statistics database.Design, Setting, and ParticipantsThis cross-sectional study was conducted among all 8 public maternity hospitals in Hong Kong. Maternal deaths were identified using prespecified search criteria, including a registered delivery episode between 2000 to 2019 and a registered death episode within 365 days after delivery. Cases as reported by the vital statistics were then compared with the deaths found in the hospital-based cohort. Data were analyzed from June to July 2022.Main Outcomes and MeasuresThe outcomes of interest were maternal mortality, defined as death during pregnancy or within 42 days after ending the pregnancy, and late maternal death, defined as death more than 42 days but less than 1 year after end of the pregnancy.ResultsA total of 173 maternal deaths (median [IQR] age at childbirth, 33 [29-36] years) were found, including 74 maternal mortality events (45 direct deaths and 29 indirect deaths) and 99 late maternal deaths. Of 173 maternal deaths, 66 women (38.2%) of individuals had preexisting medical conditions. For maternal mortality, the MMR ranged from 1.63 to 16.78 deaths per 100 000 live births. Suicide was the leading cause of direct death (15 of 45 deaths [33.3%]). Stroke and cancer deaths were the most common causes of indirect death (8 of 29 deaths [27.6%] each). A total of 63 individuals (85.1%) died during the postpartum period. In the theme-based approach analysis, the leading causes of death were suicide (15 of 74 deaths [20.3%]) and hypertensive disorders (10 of 74 deaths [13.5%]). The vital statistics in Hong Kong missed 67 maternal mortality events (90.5%). All suicides and amniotic fluid embolisms, 90.0% of hypertensive disorders, 50.0% of obstetric hemorrhages, and 96.6% of indirect deaths were missed by the vital statistics. The late maternal death ratio ranged from 0 to 16.36 deaths per 100 000 live births. The leading causes of late maternal death were cancer (40 of 99 deaths [40.4%]) and suicide (22 of 99 deaths [22.2%]).Conclusions and RelevanceIn this cross-sectional study of maternal mortality in Hong Kong, suicide and hypertensive disorder were the dominant causes of death. The current vital statistics methods were unable to capture most of the maternal mortality events found in this hospital-based cohort. Adding a pregnancy checkbox to death certificates and setting up a confidential enquiry into maternal death could be possible solutions to reveal the hidden deaths.

Prevention of maternal death: a perspective

“…The low MMR is multifactorial and related to the provision of good obstetric, medical, and surgical care, as well as good health conditions of pregnant women 6,8 . Hong Kong has an efficient transportation network, a universal lowcost healthcare system, free comprehensive high-quality antenatal and intrapartum care and emergency obstetric services 9,10 .…”

“…In a cross-sectional study on maternal death events from 2000 to 2019 in Hong Kong, the leading direct causes were suicide, hypertensive disorders, and obstetric haemorrhage, followed by amniotic fluid embolism, pregnancy-related infection, pulmonary embolism, and cardiac diseases, whereas the leading indirect causes were stroke and cancer, followed by infection (including hepatitis B) and cardiac diseases 9 . Deaths related to abortion or ectopic pregnancy have become uncommon 9,10 .…”

Analysis of Family Planning Services for Couples of Reproductive Ages Too Young, Too Old, Too Close, and Too Many (4t) With the Maternal Mortality

“…A study in Hong Kong found that the database failed to capture 90.5% of maternal deaths from public health hospitals (Cheung et al, 2023). Another study in Banten found that the odds of a maternal death during delivery being missed was 70% less than a maternal death during pregnancy being missed.…”

Maternal near miss in three tertiary-level hospitals in Hong Kong

“…However, the number of maternal mortalities may be under-reported due to the lack of a confidential enquiry system to record maternal-nearmiss morbidities. Between 2000 and 2019, suicide and hypertensive disorders were the leading causes of maternal death in Hong Kong 2 .…”