Several small studies suggest an association between drinking water salinity and the development of pre-eclampsia/eclampsia among pregnant women in Bangladesh. These studies all had very small sample sizes generated from communities in a few coastal districts.

Building on this research, the Population Council take a geospatial approach to analyze secondary data that could be replicated in other settings and conduct primary data collection in coastal areas to follow a cohort of pregnant women over time—recording drinking water salinity and development of hypertension, pre-eclampsia, or eclampsia.

The study includes interviews with 779 pregnant women when enrolled at 20 weeks gestation and during third trimester and six weeks after delivery and tests for blood pressure, urine for protein, and the salinity levels of their drinking water. The data allow analysis of the timing of salinity exposure during pregnancy as well as women’s perceptions and adaptations to high-salinity drinking water. Data from a groundwater survey, remotely sensed elevation, satellite derived rainfall, and the national health surveillance system are also included.

The primary data collection study found that pregnant women in coastal areas of Bangladesh are vulnerable to experiencing hypertension if they drink or cook with saline water.

Results find a strong association between groundwater salinity and district-level pre-eclampsia/eclampsia rates. Analyses also show higher pre-eclampsia/eclampsia rates in the low elevation coastal zone (coastal contiguous elevation under 10 meters), indicating that higher groundwater salinity results from coastal intrusion and sea level rise. Higher rates of pre-eclampsia/eclampsia are reported in the dry season; as shallow groundwater evaporates, it is not replenished with fresh water from rainfall, so the available water is more saline.

Policymakers across Bangladesh can use the data to ensure clean drinking water for pregnant women in low-lying coastal areas; monitoring for pre-eclampsia is also a priority. Reducing risk of eclampsia and pre-eclampsia will result in lower maternal mortality rates in the country.