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.

Study Overview

• Status: Recruiting
• Conditions: Pregnancy Related; Salt; Excess

Detailed Description

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

• Study Type: Observational
• Enrollment (Anticipated): 80

Contacts and Locations

• Study Contact: Name: Martina Vulin, MD; Phone Number: +38531512300; Email: martina.vulin@gmail.com

Study Locations

• Croatia
  • Osijek, Croatia, 31000
    • Recruiting
    • Osijek University Hospital
    • Contact: Martina Vulin, MD; Phone Number: +385 31 512 300; Email: martina.vulin@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

• Sampling Method: Probability Sample

Study Population

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

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort
Low-salt (LS) group; intake of < 5 g of salt per day
Normal-salt (NS) group; intake of 5 - 7.5 g of salt per day
High-salt (HS) group; intake of 7.5 - 10 g of salt per day
Very high-salt (VHS) group; intake of > 10 g of salt per day

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal systemic microvascular function	Skin microvascular reactivity assessed by Laser Doppler flowmetry (post-occlusive reactive hyperemia, iontophoresis of acetylcholine and sodium nitroprusside) - measured in perfusion units (PU)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Maternal systemic macrovascular function	Vascular ultrasound measurement of brachial artery flow mediated dilation (FMD)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Maternal uteroplacental function	Ultrasound color Doppler measurement of umbilical artery and fetal middle cerebral artery blood flow	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxidative stress - thiobarbituric acid reactive substances (TBARS)	Measurement of biomarkers of oxidative stress level. Thiobarbituric acid reactive substances (TBARS) - biomarker of lipid peroxidation.	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Matrix metalloproteinase 9	ELISA measurement of serum matrix metalloproteinase 9 level in mother serum and placental tissue sample (taken after childbirth)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy) (serum) and immediately after childbirth (placental tissue sample)
Endocan	ELISA measurement of serum endocan level - proteoglycan associated with endothelium activation	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Pregnancy outcome - duration	Duration of pregnancy (weeks and days)	the outcome measure will be assessed at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Pregnancy outcome - birth weight	Birth weight (in grams)	at one time point immediately after childbirth
Pregnancy outcome - birth length	Birth length (in cm)	at one time point immediately after childbirth
Pregnancy outcome - Apgar score	Apgar score (in Apgar score scale, a total score of 1 to 10; the higher the score, the better the baby is doing after birth)	at one time point immediately after childbirth

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	Automatic oscillometric measurement of systolic and diastolic blood pressure (in mmHg)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Heart rate	Automatic oscillometric measurement of heart rate (bpm)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Body mass index	Measurement of BMI (kg/m2)	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Body composition	Body composition and body fluid status measurement by a four-terminal portable impedance analyzer. Based on the value of skin resistance (Ohm) empirically derived formulas (the original manufacturer's software) will be used to calculate the estimated Fat Free Mass (FFM kg) and Fat (Fat Mass kg).	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)
Body fluid status	Body fluid status measurement by a four-terminal portable impedance analyzer. Based on the value of skin resistance (Ohm) empirically derived formulas (the original manufacturer's software) will be used to calculate the estimated Total Body Water (TBW L), Extracellular Water (ECW L), Intracellular Water (ICW L), Plasma Fluid (PF L) and Interstitial Fluid (IF L).	at one time point in the third trimester of pregnancy (37-38 weeks of pregnancy)

Collaborators and Investigators

• Sponsor: Josip Juraj Strossmayer University of Osijek
• Investigators: Study Chair: Ines Drenjancevic, MD, PhD, Faculty of Medicine Josip Juraj Strossmayer University of Osijek

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2021
• Primary Completion (Anticipated): December 31, 2022
• Study Completion (Anticipated): December 31, 2023

Study Registration Dates

• First Submitted: June 8, 2021
• First Submitted That Met QC Criteria: September 8, 2021
• First Posted (Actual): September 17, 2021

Study Record Updates

• Last Update Posted (Actual): September 27, 2021
• Last Update Submitted That Met QC Criteria: September 20, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Keywords: pregnancy; microcirculation; oxidative stress; endothelium; macrocirculation; salt intake; uteroplacental function
• Other Study ID Numbers: 602-04/21-08/07

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No