Study shows increased risk of death in offspring of mothers with hypertensive pregnancy disorder

Study shows increased risk of death in offspring of mothers with hypertensive pregnancy disorder

A study published today by the BMJ finds that a condition that can cause abnormally high blood pressure in pregnancy is linked to an increased risk of death in offspring from birth to young adulthood.

The findings, based on data from over two million people in Denmark, show an increased risk of death in offspring of mothers with hypertensive disorder of pregnancy (HDP) - a group of conditions that can include preeclampsia, eclampsia, high blood pressure, abnormally high blood pressure and other complications in pregnancy.

HDP affects up to 10% of pregnancies worldwide and is a leading cause of morbidity and death in mothers and their infants.

HDP has also been linked to several diseases in offspring later in life, such as metabolic syndrome (a combination of diabetes, high blood pressure and obesity), immune disorders, and neurodevelopmental and psychiatric disorders. However, evidence that HDP influences long-term mortality in offspring from birth to adolescence and beyond is lacking.

To address this knowledge gap, researchers examined the association between maternal HDP and all-cause and cause-specific mortality in offspring from birth to young adulthood.

Using data from Danish national health registries, they tracked 2.4 million people born in Denmark between 1978 and 2018 from date of birth to date of death, emigration or December 31, 2018, whichever came first.

Their primary interest was death from any cause (“all-cause mortality”), followed by 13 specific causes of death in offspring from birth to young adulthood up to age 41.

These included deaths from cardiovascular diseases, cancer, mental and behavioral disorders, diseases of the nervous and musculoskeletal system and birth defects.

Potentially influential factors such as the gender of the offspring and the mother's age at birth were taken into account, as well as the mother's level of education, income, living conditions, smoking during pregnancy and medical history.

Of the 2,437,718 offspring included in the analysis, 102,095 (4.2%) were exposed to HDP prenatally, including 68,362 (2.8%) preeclampsia or eclampsia and 33,733 (1.4%) hypertension.

During an average follow-up of 19 years, 781 (59 per 100,000 person-years) offspring of mothers with preeclampsia, 17 (134 per 100,000 person-years) of mothers with eclampsia, and 223 (44 per 100,000 person-years) died. person-years) of mothers with hypertension and 19,119 (42 per 100,000 person-years) of mothers without HDP.

The results show that all-cause mortality was higher in offspring exposed to HDP from their mothers than in the unexposed group.

Offspring exposed to HDP had a 26% higher risk (55 per 100,000 person-years) of dying from any cause than unexposed offspring. The associated increased risk of preeclampsia, eclampsia, and hypertension was 29% (59 per 100,000 person-years), 188% (134 per 100,000 person-years), and 12% (44 per 100,000 person-years), respectively.

Offspring whose mothers had severe and early-onset preeclampsia had a more than six times higher risk of death than offspring whose mothers did not have HDP. A strong association was also observed in offspring of mothers with HDP and a history of diabetes or low education levels.

Increased risks were also identified in several cause-specific deaths. For example, deaths from digestive diseases and from diseases originating in the perinatal period (during pregnancy or the first year after birth) more than doubled in offspring exposed to maternal HDP, while deaths from endocrine, nutritional, metabolic and cardiovascular diseases increased even more than 50%.

However, researchers found no significant association between maternal HDP and cancer deaths in offspring.

Since this is an observational study, the cause cannot be determined, and the researchers admit that they could not rule out the influence of some unmeasured factors such as smoking, alcohol consumption, poor diet quality, obesity and physical inactivity in the offspring.

They also point out that Denmark has universal health coverage with high-quality health services, which may limit the generalizability of the results.

Nevertheless, it was a large, long-term study based on high-quality national health data. The results were consistent even after additional sibling analysis to account for the effects of genetic factors and some unmeasured family factors, suggesting that they are robust.

Therefore, the researchers say this study provides strong evidence that maternal HDP, particularly eclampsia and severe preeclampsia, is associated with increased risk of all-cause mortality and various cause-specific mortalities in offspring from birth to young adulthood.

Further research examining the underlying physiological mechanisms between maternal HDP and offspring mortality is needed, they add.

Source:

BMJ

Reference:

Huang, C., et al. (2022) Maternal hypertensive disorder of pregnancy and mortality in offspring from birth to young adulthood: national population-based cohort study. The BMJ. doi.org/10.1136/bmj-2022-072157.

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