# Characterizing the Relationship between Uterine Activity and Placental Function Across Pregnancy with MRI

> **NIH NIH R21** · BOSTON CHILDREN'S HOSPITAL · 2022 · $227,581

## Abstract

PROJECT SUMMARY / ABSTRACT
The placenta is a vital fetal organ that serves to oxygenate, nourish, and remove waste from fetal blood in
utero. Robust maternal perfusion is essential for this function and requires high capacitance, slow blood flow to
the placenta. Maternal-placental perfusion can be temporarily compromised by uterine contractions, which
occur throughout pregnancy, also known as Braxton Hicks contractions. Healthy fetuses with normally
developed placentas have enough placental reserve capacity that Braxton Hicks contractions and minor
vascular pathology do not significantly affect necessary placental oxygen transport. However, in dysfunctional
placentas with poor reserve (as in some placentas associated with intrauterine growth restriction-IUGR) these
events may lead to hypoxic stress. There is a lack of information and quantitative data regarding the effect of
antepartum uterine activity (Braxton Hicks contractions) in human pregnancies and whether these findings may
help to characterize placental reserve and function and inform development of future tests to identify fetuses at
risk for adverse outcomes during delivery mediated by placental dysfunction. New methods to assess
uteroplacental function in humans and the impact of contractions on fetal respiratory exchange across
pregnancy in pregnancies with normally growing and IUGR fetuses are needed. Here, we will characterize
Braxton Hicks contractions across gestation, analyze spatiotemporal changes in placental oxygenation during
these contractions and monitor the effect of these placental oxygenation changes on fetal movement and organ
oxygenation via MRI. Our hypothesis is that the change in placental flow during Braxton Hicks contractions
may have a larger impact on placental oxygen transport for IUGR fetuses compared to normally growing ones.
If successful we will have identified placental and fetal MR signal changes during contractions as a possible
method to understand individual placental reserve. Such understanding may enable the development of novel
therapies and the ability to monitor changes in these dynamics is critical to the assessment of the impact of
novel therapies. Towards this end, we propose the following specific aims: Aim 1: Characterize Braxton Hicks
contractions and the associated change in placental oxygenation across gestation in pregnancies with
normally growing and IUGR fetuses. We will characterize placental oxygenation using T2* mapping approach
and analyze regional differences in placental T2*. Then we will compare and correlate differences in
pregnancies with normally growing and IUGR fetuses. Aim 2: Determine the impact of placental oxygenation
change during Braxton Hicks contractions on fetal motion and brain and liver oxygenation in pregnancies with
normally growing and IUGR fetuses. We will track fetal motion and characterize fetal brain and liver
oxygenation using T2* mapping. Then we will compare and correlate differences in pregnancies with...

## Key facts

- **NIH application ID:** 10535116
- **Project number:** 1R21HD106553-01A1
- **Recipient organization:** BOSTON CHILDREN'S HOSPITAL
- **Principal Investigator:** Esra Abaci Turk
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $227,581
- **Award type:** 1
- **Project period:** 2022-08-01 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10535116

## Citation

> US National Institutes of Health, RePORTER application 10535116, Characterizing the Relationship between Uterine Activity and Placental Function Across Pregnancy with MRI (1R21HD106553-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10535116. Licensed CC0.

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