Uterus and cervix anatomical changes and cervix stiffness evolution throughout pregnancy.

The coordinated biomechanical performance, such as uterine stretch and cervical barrier function, within maternal reproductive tissues facilitates healthy human pregnancy and birth. Quantifying normal biomechanical function and detecting potentially detrimental biomechanical dysfunction (e.g.

Equilibrium Tension and Compression Mechanical Properties of the Human Uterus.

A successful pregnancy relies on the proper cellular, biochemical, and mechanical functions of the uterus. A comprehensive understanding of uterine mechanical properties during pregnancy is key to understanding different gynecological and obstetric disorders such as preterm birth, placenta accreta, leiomyoma, and endometriosis. This study sought to characterize the macro-scale equilibrium material behaviors of the human uterus in non-pregnancy and late pregnancy under both compressive and tensile loading.

Material properties of nonpregnant and pregnant human uterine layers.

The uterus has critical biomechanical functions in pregnancy and undergoes dramatic material growth and remodeling from implantation to parturition. The intrinsic material properties of the human uterus and how they evolve in pregnancy are poorly understood. To address this knowledge gap and assess the heterogeneity of these tissues, the time-dependent material properties of all human uterine layers were measured with nanoindentation.

The Non-pregnant and Pregnant Human Cervix: a Systematic Proteomic Analysis.

Appropriate timing of cervical remodeling (CR) is key to normal term parturition. To date, mechanisms behind normal and abnormal (premature or delayed) CR remain unclear. Recent studies show regional differences exist in human cervical tissue structure.

OBGYN practice patterns regarding combination therapy for prevention of preterm birth: A national survey.

Objective: Our objective was to examine if US obstetrician-gynecologists (OBGYNs) practice outside of evidenced-based guidelines and use a combination of interventions to prevent spontaneous preterm birth (sPTB).

Study Design: An electronic survey was distributed to members of the Pregnancy-Related Care Research Network (PRCRN), and also to members of the Society of Maternal-Fetal Medicine (SMFM). The survey consisted of questions regarding physician demographics, and the use of interventions to prevent sPTB in women with 1) a prior sPTB, 2) an incidental short cervix (no prior sPTB), and 3) a history of cervical insufficiency.

Trends, gaps, and future directions of research in cervical remodeling during pregnancy: a bibliometric analysis.

Purpose: The cervix undergoes a dynamic remodeling process throughout pregnancy. Appropriate timing of cervical remodeling is essential in maintaining the fetus inside the uterus and ensuring cervical dilatation for safe delivery of the fetus at term. This study aims to determine the characteristics and trends of published articles in the field of cervical remodeling during pregnancy through a bibliometric analysis.

Progesterone alters human cervical epithelial and stromal cell transition and migration: Implications in cervical remodeling during pregnancy and parturition.

The cervix undergoes extensive remodeling throughout pregnancy and parturition. This process involves both ECM collagen degradation and cellular remodeling, which includes cell proliferation, transition and migration. Progesterone (P4) has been used clinically to delay cervical ripening and prevent preterm birth (PTB).

Oxidative stress promotes cellular damages in the cervix: implications for normal and pathologic cervical function in human pregnancy†.

A physiologic increase in reactive oxygen species throughout pregnancy is required to remodel the cervix. Oxidative stress can cause cellular damage that contributes to dysfunctional tissue. This study determined the oxidative stress-induced cell fate of human cervical epithelial and cervical stromal cells.

Anoctamin 1 antagonism potentiates conventional tocolytic-mediated relaxation of pregnant human uterine smooth muscle.

Background: Currently available tocolytic agents are not effective treatment for preterm labor beyond 48 h. A major reason is the development of maternal side effects which preclude the maintenance of an effective steady-state drug concentration. One strategy that can mitigate these side effects is utilizing synergistic drug combinations to reduce the drug concentrations necessary to elicit a clinical effect.

Longitudinal ultrasonic dimensions and parametric solid models of the gravid uterus and cervix.

Tissue mechanics is central to pregnancy, during which maternal anatomic structures undergo continuous remodeling to serve a dual function to first protect the fetus in utero while it develops and then facilitate its passage out. In this study of normal pregnancy using biomechanical solid modeling, we used standard clinical ultrasound images to obtain measurements of structural dimensions of the gravid uterus and cervix throughout gestation. 2-dimensional ultrasound images were acquired from the uterus and cervix in 30 pregnant subjects in supine and standing positions at four time points during pregnancy (8-14, 14-16, 22-24, and 32-34 weeks).

Extracellular Matrix Rigidity Modulates Human Cervical Smooth Muscle Contractility-New Insights into Premature Cervical Failure and Spontaneous Preterm Birth.

Spontaneous preterm birth (sPTB), a major cause of infant morbidity and mortality, must involve premature cervical softening/dilation for a preterm vaginal delivery to occur. Yet, the mechanism behind premature cervical softening/dilation in humans remains unclear. We previously reported the non-pregnant human cervix contains considerably more cervical smooth muscle cells (CSMC) than historically appreciated and the CSMC organization resembles a sphincter.

Correction to: Activation of an Endogenous Opsin 3 Light Receptor Mediates Photo-Relaxation of Pre-Contracting Late Gestation Human Uterine Smooth Muscle Ex Vivo.

This article was updated to correct Joy Y. Vink's name in the author listing.

Activation of an Endogenous Opsin 3 Light Receptor Mediates Photo-Relaxation of Pre-Contracting Late Gestation Human Uterine Smooth Muscle Ex Vivo.

Spontaneous preterm birth (sPTB) remains a worldwide healthcare challenge. Preterm labor (PTL) is thought to be the largest reversible cause of sPTB, but current tocolytic therapies are ineffective and associated with systemic side effects from chronic use. Therefore, identifying novel mechanisms that promote human uterine smooth muscle (hUSM) relaxation is essential to improving clinical management of PTL.

Quantitative Ultrasound Detects Smooth Muscle Activity at the Cervical Internal Os in Vitro.

The cervix has two biomechanical functions: to remain closed while the fetus develops throughout pregnancy, and to open for delivery of the fetus at full term. This dual function is principally attributed to collagen within the extracellular matrix (ECM). However, recent evidence suggests that other ECM, and non-ECM, components play a role as well.

Anisotropic Material Characterization of Human Cervix Tissue Based on Indentation and Inverse Finite Element Analysis.

The cervix is essential to a healthy pregnancy as it must bear the increasing load caused by the growing fetus. Preterm birth is suspected to be caused by the premature softening and mechanical failure of the cervix. The objective of this paper is to measure the anisotropic mechanical properties of human cervical tissue using indentation and video extensometry.

The utility of fetal fibronectin in asymptomatic singleton and twin pregnancies with a cervical length ≤ 10 mm.

To examine the utility of fetal fibronectin (fFN) for predicting spontaneous preterm birth (PTB) in asymptomatic women with a cervical length (CL) ≤10 mm compared to those with a CL 11-25 mm. Data was collected on all women with nonanomalous singleton and twin gestations who underwent transvaginal CL at a single institution between 2009 and 2012. Women with an incidental short cervix (CL ≤ 25 mm) between 22 and 32 weeks who had an fFN result within 7 days thereafter were included.

Understanding if, How, and Why Women with Prior Spontaneous Preterm Births are Treated with Progestogens: A National Survey of Obstetrician Practice Patterns.

 In 2017, the Society for Maternal-Fetal Medicine (SMFM) Guideline Committee reaffirmed that 17 -hydroxyprogesterone caproate (17-OHPC) to prevent preterm birth (PTB) is underutilized. We sought to determine what drove progestogen treatment choice of obstetricians managing pregnant women with histories of 1+ singleton spontaneous PTBs (< 37 weeks) who then delivered singleton gestations within the previous 12 months.  We recruited a nationally representative random sample of obstetricians to abstract medical records of study-qualified patients.

Cervical alterations in pregnancy.

Spontaneous preterm birth (SPTB), defined as delivery before 37 weeks' gestation, remains a significant obstetric dilemma even after decades of research in this field. Although trends from 2007 to 2014 showed the rate of preterm birth slightly decreased, the CDC recently reported the rate of preterm birth has increased for two consecutive years since 2014. Currently, 1 in 10 pregnancies in the US still end prematurely.

Functional comparison of anoctamin 1 antagonists on human uterine smooth muscle contractility and excitability.

Background: Pre-term birth is a major health care challenge throughout the world, and preterm labor represents a potentially reversible component of this problem. Current tocolytics do not improve preterm labor beyond 48 h. We have previously shown that anoctamin 1 (ANO1) channel blockade results in relaxation of pre-contracted human uterine smooth muscle (USM).

Characterization of the collagen microstructural organization of human cervical tissue.

The cervix shortens and softens as its collagen microstructure remodels in preparation for birth. Altered cervical tissue collagen microstructure can contribute to a mechanically weak cervix and premature cervical dilation and delivery. To investigate the local microstructural changes associated with anatomic location and pregnancy, we used second-harmonic generation microscopy to quantify the orientation and spatial distribution of collagen throughout cervical tissue from 4 pregnant and 14 non-pregnant women.

Anoctamin Channels in Human Myometrium: A Novel Target for Tocolysis.

Background: Spontaneous preterm labor leading to preterm birth is a significant obstetric problem leading to neonatal morbidity and mortality. Current tocolytics are not completely effective and novel targets may afford a therapeutic benefit.

Objective: To determine whether the anoctamin (ANO) family, including the calcium-activated chloride channel ANO1, is present in pregnant human uterine smooth muscle (USM) and whether pharmacological and genetic modulation of ANO1 modulates USM contraction.

The pathophysiology of human premature cervical remodeling resulting in spontaneous preterm birth: Where are we now?

Approximately one in ten (approximately 500,000) pregnancies results in preterm birth (PTB) annually in the United States. Although we have seen a slight decrease in the U.S.