Low-Sodium Diet for Postpartum Blood Pressure Control

This study is a prospective, single-center randomized controlled trial (RCT). Due to the nature of the intervention, providers and participants will not be blinded to the study group. In this RCT, researchers will assess if sodium restriction (less than 2000 mg daily) in the postpartum setting leads to lower blood pressure (BP) in those diagnosed with a hypertensive disorder of pregnancy (HDP). Individuals diagnosed with HDP (gestational hypertension, pre-eclampsia, chronic hypertension with superimposed pre-eclampsia) after 34 weeks' gestation will be eligible for the study. Recruitment will occur in the hospital prior to their first food intake postpartum. Following delivery, participants will be randomized 1:1 to either the experimental group (diet with \< 2000 mg sodium daily) or the control group (diet with variable sodium content per preference). While in the hospital, the experimental group will receive a "low salt diet" and the control group will receive a "regular diet" provided by hospital dietary services. Following discharge, participants will be provided meals from Meals on Wheels according to their assigned study diet for a total of seven days following delivery. They will also be provided a log to record the food they eat each day. The daily sodium content will be calculated for each participant and averaged over the 7-day study period. While in the hospital, participants will have their BP checked and recorded every 4 hours by nursing staff. At the time of discharge, participants will be provided with a BP cuff and instructions for how to measure their BP at home. They will be asked to check and record their BP at least once daily. The primary outcome will be the difference in mean arterial pressure (MAP) between groups on postpartum day 7. The MAP will be calculated for each participant based on their recorded BP values on postpartum day 7. Secondary outcomes will be the difference in MAP on postpartum day 3 and the difference in 30-day hospital readmission rates for hypertension between groups.