Pregnancy-induced remodeling of the murine reproductive tract: a longitudinal in vivo magnetic resonance imaging study

Aileen C Suarez; Clara J Gimenez; Serena R Russell; Maosen Wang; Jennifer M Munson; Kristin M Myers; Kristin S Miller; Steven D Abramowitch; Raffaella De Vita

doi:10.1038/s41598-023-50437-1

Pregnancy-induced remodeling of the murine reproductive tract: a longitudinal in vivo magnetic resonance imaging study

Sci Rep. 2024 Jan 5;14(1):586. doi: 10.1038/s41598-023-50437-1.

Authors

Aileen C Suarez¹, Clara J Gimenez¹, Serena R Russell², Maosen Wang³, Jennifer M Munson³, Kristin M Myers², Kristin S Miller⁴, Steven D Abramowitch⁵, Raffaella De Vita⁶

Affiliations

¹ STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, 325 Stanger Street, Blacksburg, VA, 24061, USA.
² Department of Mechanical Engineering, Columbia University, 234 S W. Mudd, New York, NY, 10027, USA.
³ Fralin Biomedical Research Institute, Virginia Tech, 4 Riverside Circle,, Roanoke, VA, 24016, USA.
⁴ Department of Mechanical Engineering, The University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX, 75080, USA.
⁵ Department of Bioengineering, University of Pittsburgh, 3700 O'Hara Street, Pittsburgh, PA, 15261, USA.
⁶ STRETCH Lab, Department of Biomedical Engineering and Mechanics, Virginia Tech, 325 Stanger Street, Blacksburg, VA, 24061, USA. devita@vt.edu.

Abstract

Mammalian pregnancy requires gradual yet extreme remodeling of the reproductive organs to support the growth of the embryos and their birth. After delivery, the reproductive organs return to their non-pregnant state. As pregnancy has traditionally been understudied, there are many unknowns pertaining to the mechanisms behind this remarkable remodeling and repair process which, when not successful, can lead to pregnancy-related complications such as maternal trauma, pre-term birth, and pelvic floor disorders. This study presents the first longitudinal imaging data that focuses on revealing anatomical alterations of the vagina, cervix, and uterine horns during pregnancy and postpartum using the mouse model. By utilizing advanced magnetic resonance imaging (MRI) technology, T1-weighted and T2-weighted images of the reproductive organs of three mice in their in vivo environment were collected at five time points: non-pregnant, mid-pregnant (gestation day: 9-10), late pregnant (gestation day: 16-17), postpartum (24-72 h after delivery) and three weeks postpartum. Measurements of the vagina, cervix, and uterine horns were taken by analyzing MRI segmentations of these organs. The cross-sectional diameter, length, and volume of the vagina increased in late pregnancy and then returned to non-pregnant values three weeks after delivery. The cross-sectional diameter of the cervix decreased at mid-pregnancy before increasing in late pregnancy. The volume of the cervix peaked at late pregnancy before shortening by 24-72 h postpartum. As expected, the uterus increased in cross-sectional diameter, length, and volume during pregnancy. The uterine horns decreased in size postpartum, ultimately returning to their average non-pregnant size three weeks postpartum. The newly developed methods for acquiring longitudinal in vivo MRI scans of the murine reproductive system can be extended to future studies that evaluate functional and morphological alterations of this system due to pathologies, interventions, and treatments.

MeSH terms

Animals
Female
Humans
Magnetic Resonance Imaging*
Mammals
Mice
Postpartum Period
Pregnancy
Research Design
Uterus* / diagnostic imaging
Vagina / diagnostic imaging

Grants and funding

2053851/NSF