Dietary Salt During Pregnancy and Maternal Vascular Function

Influence of Dietary Salt Intake During Pregnancy on Maternal Systemic and Uteroplacental Vascular Function

The main goal of this study is to investigate the association of dietary salt intake during pregnancy with systemic micro- and macrovascular reactivity and uteroplacental vascular function of the mother, and to examine the potential impact of elevated oxidative stress on this association. Also, the aim is to investigate whether there is an association between excessive salt intake during pregnancy and the outcome of pregnancy.

During the study pregnant women at the third trimester of pregnancy (37-38 weeks of pregnancy) will have one study visit during which following procedures will be done:

• measurement of maternal systemic microvascular function by Laser Doppler flowmetry (post-occlusive reactive hyperemia, iontophoresis of acetylcholine and sodium nitroprusside)
• measurement of maternal systemic macrovascular function by vascular ultrasound measurement of brachial artery flow mediated dilation (FMD)
• measurement of maternal uteroplacental function by ultrasound color Doppler measurement of umbilical artery and fetal middle cerebral artery blood flow
• venous blood sampling; serum will be stored for measurement of oxidative stress, matrix metalloproteinase 9 and endocan level
• 24-hour urine natriuresis (to estimate daily salt intake)
• measurement of blood pressure, heart rate, height and weight, body composition

Immediately after the childbirth following procedures will be done:

• assessment of pregnancy outcome (duration of pregnancy, child birth weight, child birth length and Apgar score)
• placental tissue will be taken and stored for measurement of matrix metalloproteinase 9

Inclusion Criteria:

• healthy pregnant women in the third trimester of pregnancy (37-38 weeks of pregnancy)

Exclusion Criteria:

• smoking
• prenatal hypertension
• thrombophilia
• low molecular weight heparin use
• coronary heart disease
• preconception diabetes
• gestational diabetes
• renal impairment
• cerebrovascular and peripheral artery disease
• any other preconception disease that could affect vascular and endothelial function