Drinking water salinity and the risk of (pre)eclampsia and gestational hypertension in coastal Bangladesh: impacts of climate change

Hypertensive disorders in pregnancy are among the leading causes of death and disabilities in women of child-bearing age in low-income countries. Despite the high burden, the pathophysiology and aetiology of these disorders are poorly understood, making effective prevention difficult. Excessive dietary salt intake is an established risk factor for hypertension, but much less is known about the health effects of water salinity. This epidemiological study investigated the relationship between high salinity in drinking water and the risk of (pre)eclampsia and gestational hypertension among pregnant women in a rural coastal community in Dacope, Bangladesh, where both surface- and groundwater have been affected by severe salinity, exacerbated by the effects of sea-level rise and climate change. The population-based case-control study accrued 202 cases of (pre)eclampsia and gestational hypertension and 1,006 controls. The study showed that women in Dacope were exposed to exceptionally high levels of sodium in their drinking water, and found a significant association with the risk of (pre)eclampsia and gestational hypertension. The risks increased in a dose-response manner for increasing quartiles of sodium concentrations in drinking water (ORs 3.36 [95% CI 2.07 – 5.60], 4.35 [2.61 - 6.94] and 5.40 [3.28 – 8.92]), (p-trend