Beyond MARS: Magnetic Resonance Study: A Novel Assessment of Placental Perfusion During Pregnancy

The purpose of this study is to evaluate the flow of oxygen and blood necessary for nutrient transfer across the placenta during the second and third trimesters in pregnancy in women who are obese before pregnancy compared to women who have an average weight before pregnancy. This study will evaluate blood flow across the placenta by functional Magnetic Resonance Imaging (fMRI) using arterial spin labeling (ASL). The investigators hypothesize that there will be differences in placental oxygenation and blood flow among women with obesity as compared to those with normal weight. Participants will be asked to complete Magnetic Resonance Imaging scans (MRIs), the first in the second trimester at 20-24 weeks and the second in the third trimester at 30-34 weeks.

Study Overview

• Status: Not yet recruiting
• Conditions: Placenta Diseases
• Intervention / Treatment: Diagnostic test: functional Magnetic Resonance Imaging (fMRI)

Detailed Description

The transfer of oxygen and nutrients from the mother to the baby across the placenta is essential to successful pregnancy outcomes. Conversely, poor transfer of oxygen from the mother to the baby through the placenta is associated with adverse outcomes, including poor fetal growth, preterm delivery, and stillbirth. Babies need oxygen to maintain good health. Babies born to women who are obese before pregnancy have a higher risk of experiencing health problems in pregnancy and long-term health problems such as metabolic syndrome, obesity, and diabetes. Obesity has continued to increase in the United States over the past decades, and a quarter of pregnancy complications, such as preterm birth, gestational diabetes, hypertension, and large gestational infants, can be attributed to maternal obesity.

In this study, the investigators propose using a novel method, arterial spin labeling (ASL)) to measure placental blood flow. The study aims to evaluate the feasibility and reliability of assessing placental blood flow by this novel method. The investigators will also evaluate the mean global placental perfusion of second and third trimester placentas among obese women as compared to those with a normal weight before pregnancy. To provide an innovative and comprehensive evaluation of placental oxygen delivery and insights into the delivery of nutrients, investigators will compare global placental perfusion of second and third trimester placentas with measurements of placental oxygenation by R2* relaxation rates.

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Olivert Mbah; Phone Number: 847-570-2243; Email: OMbah@northshore.org
• Study Contact Backup: Name: Caitlin A MacGregor; Phone Number: 847-570-2243; Email: CMacgregor@northshore.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Pregnant women at 20-24 weeks gestation. 15 obese (OB) women and 15 normal weight (NL) will be recruited to participate in the study. OB is defined as pre-pregnancy body mass index greater than or equal to 30 kg/m2, and NL is defined as pre-pregnancy body mass index between 18.5-24.9 kg/m2 without comorbidities.

Description

Inclusion Criteria:

• singleton pregnancy

Exclusion Criteria:

• multifetal gestation
• congenital anomaly
• claustrophobia, or ineligible for MRI (incompatible implanted medical device)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Normal Weight; Body Mass Index (BMI) 18.5-24.9 kg/m^2	Diagnostic test: functional Magnetic Resonance Imaging (fMRI); Participants will undergo a functional Magnetic Resonance Imaging (fMRI) using arterial spin labeling (ASL) and other Magnetic Resonance (MR) sequences
Obese; Pre-pregnancy Body Mass Index (BMI) ≥ 30.0 kg/m^2	Diagnostic test: functional Magnetic Resonance Imaging (fMRI); Participants will undergo a functional Magnetic Resonance Imaging (fMRI) using arterial spin labeling (ASL) and other Magnetic Resonance (MR) sequences

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inter - rater reliability of assessing placental blood flow by arterial spin labeling (ASL)	Evaluated using a two-way mixed intraclass correlation coefficient for consistency	6 weeks after the delivery
Mean placental perfusion in second and third trimester	The mean global placental perfusion of second and third-trimester placentas among participants with obesity (Body Mass Index measured in kg/m^2, calculated using weight in kilograms and height in meters) as compared to those with a normal weight (kilograms) before pregnancy will be evaluated.	6 weeks after the delivery
Mean R2* relaxation rates in second and third trimester	the Mean R2* relaxation rates will be used to correlate the global placental perfusion of second and third trimester placentas with measurements of placental oxygenation.	6 weeks after the delivery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perinatal outcomes including hypertensive disorders of pregnancy, gestational diabetes, preterm birth, small for gestational age, NICU admission, and stillbirth.	The prevalence and incidence of outcomes such as hypertensive disorders of pregnancy, gestational diabetes, preterm birth, small for gestational age, NICU (Neonatal Intensive Care Unit) admission, stillbirth will be assessed.	6 weeks after the delivery

Collaborators and Investigators

• Sponsor: NorthShore University HealthSystem
• Investigators: Principal Investigator: Caitlin MacGregor, NorthShore University HealthSystem

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: February 16, 2024
• First Submitted That Met QC Criteria: March 13, 2024
• First Posted (Actual): March 15, 2024

Study Record Updates

• Last Update Posted (Actual): March 15, 2024
• Last Update Submitted That Met QC Criteria: March 13, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: Placental Perfusion; Placental oxygenation
• Additional Relevant MeSH Terms: Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Placenta Diseases
• Other Study ID Numbers: EH23-302

Drug and device information, study documents

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