Poster CC1 - Development of a Platform for Quantifying Cervical Mucus Hydration for Preterm Birth Risk Assessment

Thursday, October 24, 2024

2:45 PM - 3:45 PM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Mara Manolescu

Undergraduate Student
University of Kansas
Lawrence, Kansas, United States

Co-Author(s)

KB

Katy Belcher, BS

Graduate Student
Washington University in St. Louis, United States

Primary Investigator(s)

CO

Christine O'Brien

Primary Investigator
Washington University in St. Louis, United States

Introduction: Preterm birth, defined as birth occurring prior to 37 weeks of gestation, is the leading cause of newborn mortality. There is an unmet need for an adequate preterm birth risk assessment tool that can be used in pregnant women so preventative action may be taken. Previous studies found that the cervical mucus of women at high risk for preterm birth has distinct properties, including increased permeability. It is hypothesized that this makes bacteria more likely to reach the uterus and cause infection. Importantly, ascending infection is the leading known cause of preterm birth. Mucus hydration has shown to be correlated to mucus permeability and could be an important biomarker for preterm birth risk. However, simple protocols for efficient mucus extraction and hydration assessment are lacking. It is difficult to obtain large volumes of cervical mucus, and thus it is imperative that the full volume collected (often ~200 μL) can be used for analysis. Herein, we have developed a mucus transfer method that optimizes transfer of cervical mucus from a swab into an Eppendorf tube for maximal volume preservation without affecting mucus hydration. This method includes a novel mucus transfer device ensuring maximal mucus volume transfer from the swab to Eppendorf tube. In addition, a simple light-based hydration assay has been designed. The goal of this project is to create an efficient, non-invasive, clinically relevant cervical mucus hydration measurement tool using light-based hydration detection to provide quantitative risk assessment for preterm birth.

Materials and

Methods: Previous work showed a hydrophobic brush to be the easiest swab for collecting cervical mucus without altering its hydration in a clinical setting. A mucus transfer device was built with two parts: a rectangular holder and a slider that fits inside. The parts were designed in Autodesk Fusion and 3D printed. An Eppendorf tube fits securely in the holder and a triangular cutout on the slider allows the swab to scrape against the side and efficiently transfer mucus into the Eppendorf tube.
To test the effectiveness of the device, a synthetic cervical mucus was used which was created following a published protocol that used porcine gastric mucin (type III) as the mucus backbone. To quantify the device performance, the weight of the mucus collected on the brush, the weight of the mucus successfully transferred into the Eppendorf tube, and the weight of the mucus left on the brush after the transfer were measured. Percent weights were calculated from these values. Five trials were performed using the device to scrape the swab five times. Five trials were then performed without the device by scraping the swab directly into the Eppendorf tube five times.
A light-based hydration sensor that measures the light absorption of mucus in the short-wave infrared, a spectral region with strong water absorption, is under development and will be tested in the upcoming weeks. The sensor utilizes a 1300 nm LED and an indium gallium arsenide photodiode which is sensitive to photons in this spectral range.

Results, Conclusions, and Discussions: The average weight percent of synthetic cervical mucus successfully transferred from the swab into the Eppendorf tube with the device was 50.1% while the average weight percent successfully transferred without the device was 38.8%. The difference proved to be statistically significant after a two-sample unpaired T-test resulting in a p-value of 0.0063. The average weight percent of mucus still on the swab after the transfer with the device was 30.7% while the average weight percent still on the swab after the transfer without the device was 60.3%. This difference also proved to be statistically significant after a two-sample unpaired T-test with a resulting p-value of 0.00000756. These results show that the device allowed more mucus to transfer into the Eppendorf tube and removed more mucus from the swab in comparison to transferring without the device.
There are several ideas to further improve the mucus transfer device. First, when the device was used for transfer, the swab was observed to lose some mucus when entering the Eppendorf through the triangular cutout of the slider because it would scrape the edges of the cutout. Second, having to hold the slider during the transfer limited user control of the device. To correct these complications, a redesign with an increased cutout size and adjustments to the holder so the slider may fit securely is underway.
In summary, the results suggest this device enabled significantly more mucus volume transfer from a swab to an Eppendorf tube compared to scraping against the side of the tube alone. This important and practical step sets the stage for creating a hydration assessment tool for preterm birth risk assessment in pregnant women, with the goal of enabling preventative action to be taken. The light-based hydration sensor is under development and preliminary results are expected in the coming weeks. This work not only paves the way towards collecting cervical mucus for hydration measurement, but the mucus transfer device may also be adapted to efficiently collect samples from varying mucosal epithelial to investigate their biophysical properties as a mode of developing diagnostic and treatment methods for disease.

Acknowledgements (Optional):