The mean SBP of the pregnant women south-western coastal Bangladesh is 102.4 mmHg among individuals who drank rainwater, 112.7 mmHg among filter users, 112.6 among pond water users and 119.4 among brackish groundwater users (tube-well water). The investigators assumed that drinking tube-well water may correspond with the dry season information and rainwater data correspond to the wet season information. Therefore, the assumption is that drinking MAR water would be able to reduce 17 mm Hg of systolic blood pressure. Considering crude birth rate of 26/1000 population, the assumption is there may be 88 birth during the seven months duration of the proposed study. Considering 88 pregnancies, the investigators will have 95% power to detect the effect of MAR in our main study. Stata command: sampsi 119.4 102.4, sd1(26.7) sd2(16.2) n1(44) n2(44) Data Analysis Blood Pressure The investigators will conduct an intention-to-treat analysis. Since the data will be longitudinal and on individual participants, generalized estimating equations (GEE) will be used with an appropriate autoregressive correlation structure, to account for repeated measures within individual study participants, and robust standard errors to allow for possible misspecification of the variance structure. The outcome is continuous blood pressure, which will be regressed on an indicator variable for access to MAR water, and dummy variables for the study sites to account for mean differences between communities... The interpretation of such a GEE model's output is the population average association of MAR with blood pressure, conditional on study site. The study investigators will further adjust for age, sex, body mass index, smoking, alcohol intake, family history of hypertension, and hypertensive medication of the participants. In secondary analyses, the association between drinking MAR water and urinary sodium and protein concentrations will be evaluated. For the pregnant women, we will control for the gestational week.