Littérature scientifique sur le sujet « Active uterine contraction »

Because platelet activation and serotonin have been implicated in preeclamptic hypertension, we investigated the effect of pregnancy on the contractile response to this agent. Prior studies have shown that the vascular contractions to norepinephrine, angiotensin II, and thromboxane are reduced during normal pregnancy by the altered release of endothelium-derived vasoactive substances. We hypothesized that the contraction to serotonin would also be reduced during pregnancy by an endothelium-dependent mechanism. Isolated ring segments from uterine and carotid arteries of near-term pregnant and nonpregnant guinea pigs were studied after stimulating a small amount of active tone with prostaglandin F2 alpha. Serotonin (10(-8) to 10(-5) M) contractile responses of both arteries were reduced by pregnancy. Regardless of pregnancy status, the contractile responses of the uterine artery to serotonin were severalfold greater than that of the carotid artery whose maximum averaged only 10% of the 120 mM KCl contraction. Denudation of uterine artery abolished acetylcholine-stimulated relaxation in vessels from pregnant and nonpregnant animals. However, serotonin-induced contractions were enhanced by denudation only in ring segments obtained from pregnant animals. Nitric oxide synthase inhibition by either NG-monomethyl-L-arginine (L-NMMA) or N omega-nitro-L-arginine and cyclooxygenase inhibition by indomethacin had no effect on serotonin-induced contraction of intact uterine artery regardless of pregnancy. L-NMMA modestly enhanced the intact carotid arterial response to 10(-5) M serotonin independent of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary dysmenorrhea is a common occurrence in adolescent women and is a type of chronic inflammation. Dysmenorrhea is due to an increase in oxidative stress, which increases cyclooxygenase-2 (COX-2) expression, increases the concentration of prostaglandin F2α (PGF2α), and increases the calcium concentration in uterine smooth muscle, causing excessive uterine contractions and pain. The polyphenolic compound oleocanthal (OC) in extra virgin olive oil (EVOO) has been shown to have an anti-inflammatory and antioxidant effect. This study aimed to investigate the inhibitory effect of extra virgin olive oil and its active ingredient oleocanthal (OC) on prostaglandin-induced uterine hyper-contraction, its antioxidant ability, and related mechanisms. We used force-displacement transducers to calculate uterine contraction in an ex vivo study. To analyze the analgesic effect, in an in vivo study, we used an acetic acid/oxytocin-induced mice writhing model and determined uterus contraction-related signaling protein expression. The active compound OC inhibited calcium/PGF2α-induced uterine hyper-contraction. In the acetic acid and oxytocin-induced mice writhing model, the intervention of the EVOO acetonitrile layer extraction inhibited pain by inhibiting oxidative stress and the phosphorylation of the protein kinase C (PKC)/extracellular signal-regulated kinases (ERK)/ myosin light chain (MLC) signaling pathway. These findings supported the idea that EVOO and its active ingredient, OC, can effectively decrease oxidative stress and PGF2α-induced uterine hyper-contraction, representing a further treatment for dysmenorrhea.

Contributing factor to uterus contraction mechanism is the imbalance of the extracellular calcium level. When extracellular calcium level is inadequate, response of the myometrium to oxytocin decreased and the calcium influx inter-cell membranes are suppressed, thus inhibit uterine contractions. The aim of this research is to know the correlation between levels of calcium and the strength of uterine contraction in the active phase of first stage labor. This was a cross-sectional analytic correlative study in the Dr. Rasidin Hospital Padang and UPTD Health Laboratory in West Sumatra province, in was conducted from November 1st, 2014 till February 2016. Sampling was takes by using non probability sampling with consecutive sampling. Subjects of this research were the active phase of first stage labor of 62 people. Kolmogorof Smirnov normality test was used to the normality of the data. Pearson correlation test was conducted to examine the correlation between dependent and independent variables. Mean levels of calcium in the the stage I of labor respondents active phase (8.94 ±0,71), while mean strength of uterine contractions in active phase of first stage labor(56.77±11,84), there was positive correlation (r = 0,62) between the levels of calcium in the strength of uterine contractions (p < 0.05). The conclusion of the study there was a significant correlation between the levels of calcium in the strength of uterine contractions.

Background During labor, ephedrine is widely used to prevent or to treat maternal arterial hypotension and restore uterine perfusion pressure to avoid intrapartum fetal asphyxia. However, the effects of ephedrine on uterine blood flow have not been studied during uterine contractions. The purpose of the study was to assess the effects of ephedrine on uterine artery velocities and resistance index using the Doppler technique during the active phase of labor. Methods Ten normotensive, healthy parturients with uncomplicated pregnancies at term received intravenous ephedrine during labor to increase mean arterial pressure up to a maximum of 20% above their baseline pressure. Peak systolic and end-diastolic Doppler flow velocities and resistance indices were measured in the uterine artery before and immediately after administration of bolus intravenous ephedrine and after ephedrine washout. Umbilical and fetal middle cerebral arterial resistance indices and fetal heart rate were also calculated. Results After ephedrine administration, mean arterial pressure increased by 17 +/- 4%. End-diastolic flow velocity in the uterine artery at peak amplitude of uterine contraction was restored to 74% of the value observed in the absence of contraction. The systolic velocity was totally restored, and the uterine resistance index was significantly decreased, compared with the values in the absence of contraction. Between uterine contractions, ephedrine induced similar but less marked effects. Fetal hemodynamic parameters were not altered by ephedrine administration. Conclusions Bolus administration of intravenous ephedrine reversed the dramatic decrease in diastolic uteroplacental blood flow velocity and the increase in resistance index during uterine contraction, without altering fetal hemodynamic parameters. This suggests that the increase in uterine perfusion pressure during labor could in part restore uterine blood flow to the placenta during uterine contraction.

Hypothesis/aims of study. Myometrial relaxation and contraction require synchronous cellular interactions. At present, it has been established that the coordination of myometrial contractile activity is carried out by a conduction system constructed from gap junctions with intercellular channels. There are no clinical data on inhibiting (nitric oxide synthase) and activating (connexin-43) factors of uterine contractile activity in the myometrium during pregnancy and parturition in the published literature. This study was undertaken to measure the expression levels of nitric oxide synthase, adhesion molecules CD51, CD61, and connexin-43 in the myometrium during pregnancy and parturition; and to assess the role of inhibitory and activating factors in the development of uterine contractile activity. Study design, materials and methods. An immunohistochemical study of myometrial biopsy specimens obtained from the lower uterus segment during cesarean section was performed in eight women with a full-term physiological pregnancy, in another eight individuals in the active phase of uncomplicated parturition, and in eight patients with uterine inertia. Integrins (CD51 and CD61 proteins) were used as markers of cell adhesion. Localization and the number of intercellular contacts were assessed by measuring the expression level of connexin-43, with the intensity of oxidative processes assessed by nitric oxide synthase activity. Results. In the myometrium, in the active phase of physiological parturition, a three-fold increase in the expression of activating (CD51, CD61, and connexin-43) factors of uterine contractile activity and a five-fold decrease in that of inhibitory (nitric oxide synthase) ones occur compared to those in full-term physiological pregnancy. Conclusion. In the pathogenesis of uterine inertia and resistance to labor induction, an important role is played by the decreased expression of adhesion molecules (CD51, CD61) and connexin-43 and the increased expression of nitric oxide synthase in the myometrium.

Background: Recently, there have been some trials to use dexmedetomidine in the obstetric field but concerns regarding the drug include changes in uterine contractions after labor. We aimed to evaluate the effects of dexmedetomidine on the myometrial contractions of pregnant rats.Methods: In a pilot study, the contraction of the myometrial strips of pregnant Sprague-Dawley rats in an organ bath with oxytocin at 1 mU/ml was assessed by adding dexmedetomidine from 10-6 to 10-2 M accumulatively every 20 min, and active tension and the number of contractions were evaluated. Then, changes in myometrial contractions were evaluated from high doses of dexmedetomidine (1.0 × 10−4 to 1.2 × 10−3 M). The effective concentrations (EC) for changes in uterine contractions were calculated using a probit model.Results: Active tension and the number of contractions were significantly decreased at 10-3 M and 10-4 M dexmedetomidine, respectively (P < 0.05). A complete loss of contractions was seen at 10-2 M. Dexmedetomidine (1.0 × 10−4 to 1.2 × 10−3 M) decreased active tension and the number of contractions in a concentration-dependent manner. The EC95 of dexmedetomidine for inhibiting active tension and the number of contractions was 5.16 × 10-2 M and 2.55 × 10-5 M, respectively.Conclusions: Active tension of the myometrium showed a significant decrease at concentrations of dexmedetomidine higher than 10-3 M. Thus, clinical concentrations of dexmedetomidine may inhibit uterine contractions. Further research is needed for the safe use of dexmedetomidine in the obstetrics field.

Background Propofol is an alternative to thiopental as an intravenous induction agent for cesarean section. Because it has relaxant effects on vascular and other smooth muscles, the authors set out to determine whether propofol has any effect on pregnant human uterine smooth muscle in an isolated preparation. Methods Myometrial specimens were excised from 10 parturients undergoing elective cesarean section. The muscle strips were suspended in tissue baths and isometric tension was recorded. After establishment of rhythmic contractions in the buffer solution as a control, propofol (0.5 to 10 microg/ml) in fat emulsion was applied cumulatively to the bath. The effect of the fat emulsion at equivalent concentrations was also examined. Results Propofol concentrations of 2.7 x 10(-6) M (0.5 microg/ml) and 1.1 x 10(-5) M (2 microg/ml) had no significant effect on the active tension developed by muscle contraction. However, propofol at concentration of 5.5 x 10(-5) M (10 microg/ml) reduced the active tension by 45% (P &lt; 0.02) compared with the control value. The fat emulsion had no effects on the active tension. Conclusions These results imply that the decline in the active tension of muscle contraction was most likely caused by propofol and not by the fat emulsion. However, the propofol concentrations needed to produce a significant reduction in the uterine muscle tension appear to be much greater than the free propofol concentrations reported by others during cesarean section.

Introduction Normal labor process duration varies between 4 to 24 hours since the occurrence of uterine contractions which cause changes in the cervix. Adequate contractions are needed to induce labor to proceed normally. The active phase of the first stage of labor is considered more tiring and painful because uterine activity increases. In this phase, there is often an increase in adrenaline production which has the potential to inhibit contractions and delay the labor process. Nipple stimulation is one method that can be used to increase uterine contractions. This technique can stimulate the formation of natural oxytocin in the mother and channel it to the uterus, thus it increases uterine contractions. Objectives: This study aimed to find analyzed the effect of nipple stimulation on the labor progress and implement the best application of nipple stimulation Method: This EBCR using the Google Scholar database and PubMed. The articles were limited to original article and published from 2017-2022. According to the inclusion criteria and exclusion criteria we have found 2 articles met the criteria. The articles were obtained and critically reviewed using 3 aspects, namely the validity, the importancy, and applicability. Result: in this study the duration of first stage of labor were considered faster after the application of nipple stimulation long first stage in cases. The first stage was 2 hours faster than the average duration of the first stage , which is 1 hour per 1 cm. Conclusion: Nipple stimulation is one od the non pharmacological intervention that can be used an an option to increase the contraction during labor.

OBJECTIVE: The study intends to identify the presence of clinical indicators of pain during labor and to correlate the verbal reference of pain intensity with uterine contractions as a proposal to validate the clinical nursing diagnosis Labor Pain. METHOD: Observational study of the 22 clinical indicators that represented the defining characteristics for the diagnosis. RESULTS: There were 55 participants in labor (18 in the initial active stage, 6 in the final active stage and 31 in both stages), over 18 years old, in their first pregnancy, with effective contractions and cervical dilation of 4cm or more. Among the 22 defining characteristics tested, 6 were present in most participants during the two stages: verbal or codified report, noted evidence of uterine contraction, altered muscle tension, noted evidence of pain, expressive behavior and facial expression of pain. There were differences between the stages in relation to perspiration, facial expression of pain, protective gestures, anodyne position, distractive behavior, self-focus and perineum pressure feeling. CONCLUSIONS: A positive linear correlation was noted between pain intensity scores and the extent of intra-uterine pressure in the initial stage. Labor pain was proven to be compatible with a nursing diagnosis.

In uterine smooth muscle, the effects of Excoecaria grahamii are not yet documented. To fill this gap, we investigated the pharmacological effect of Excoecaria grahamii on the contraction of the rat isolated uterine horns. The isolated segments were exposed to different concentrations of the aqueous extract of Excoecaria grahamii leaves and pharmacological drugs. The results showed that Excoecaria grahamii aqueous extract decreased the amplitude and frequency by concentration-related manner. I C 50 values were 2.4 and 2.6, respectively, for amplitude and frequency. Our study revealed that the extract did not act through histamine H2-receptors or the nitric oxide pathway. It also inhibited uterine contractions induced by oxytocin and potassium chloride (KCl). These data suggest that Excoecaria grahamii active compound can be used for calming uterine contractions. The action of Excoecaria grahamii showed that it can be useful to fight against diseases which caused uterotonic effects. It can be useful to prevent preterm birth and pains caused by menstruations but further investigation is needed to clarify the mechanism action.

Cette thèse a développé une approche originale pour quantifier les incertitudes liées aux propriétés hyperélastiques des tissus mous, en utilisant à la fois des probabilités précises et imprécises. Le protocole de calcul a été étendu pour quantifier les incertitudes dans les contractions utérines actives lors des simulations du deuxième stade du travail. De plus, une simulation de la descente foetale a été créée, intégrant des données de contraction utérine active basées sur l'IRM et une quantification d'incertitude associée. L'étude a révélé que l'Expansion du Chaos Polynomial (PCE) non intrusif est plus efficace que les simulations directes de Monte Carlo.Ce travail met en évidence l'importance de quantifier et de propager les incertitudes dans les propriétés hyperélastiques des tissus utérins lors des simulations de travail, améliorant ainsi la fiabilité des résultats de simulation. Pour la première fois, il aborde la quantification des incertitudes des contractions utérines actives pendant le travail, assurant des résultats de simulation fiables et valides. La simulation de la descente foetale, cohérente avec les données théoriques et IRM, valide la précision des modèles en reflétant les processus physiologiques, soulignant la nécessité d'inclure les contractions utérines actives pour des résultats plus réalistes. L'étude souligne également l'importance d'évaluer la sensibilité globale des paramètres, l'incertitude et les résultats de simulation pour des applications cliniques fiables. En conclusion, cette recherche fait progresser de manière significative les simulations de l'accouchement en fournissant un cadre robuste pour la quantification des incertitudes, améliorant ainsi la fiabilité des résultats de simulation et soutenant une meilleure prise de décision clinique.Les travaux futurs étendront le processus à un modèle complet du système pelvien, incluant l'os du bassin, les ligaments et d'autres organes (comme la vessie, le rectum) pour simuler l'ensemble du processus de délivrance. Des comportements plus complexes des tissus mous pelviens seront étudiés pour mieux décrire l'interaction foetale pendant le travail. L'utilisation de données IRM 3D, si disponibles, permettra une meilleure évaluation, notamment pour la rotation foetale lors de l'expulsion. Un modèle complet du bassin maternel sera couplé à l'apprentissage par renforcement pour identifier les mécanismes de délivrance. De plus, une combinaison plus complexe d'orientations de fibres sera envisagée. Pour améliorer la méthode de Monte Carlo, des techniques de réduction de la variance et des stratégies d'optimisation telles que l'échantillonnage par importance, l'échantillonnage hypercube latin et les méthodes de Monte Carlo par chaînes de Markov seront utilisées pour réduire la taille des échantillons tout en maintenant la précision. Des méthodes pour une convergence plus rapide et une précision accrue dans la quantification des incertitudes, comme discuté par Hauseux et al. (2017), seront explorées. D'autres formulations de la méthode des éléments finis stochastiques (SFEM), comme la méthode SFEM spectrale stochastique (SSFEM), seront considérées pour la quantification des incertitudes, et des méthodes intrusives comme le stochastique-Galerkin seront utilisées pour leurs avantages computationnels. Ces approches pourraient améliorer la quantification des incertitudes dans les études futures.Enfin, l'approche développée pourrait être adaptée à la modélisation spécifique au patient et aux simulations de complications de la délivrance, permettant d'identifier les risques et les solutions thérapeutiques potentielles pour des interventions médicales personnalisées et des résultats améliorés pour les patients
Approximately 0.5 million deaths during childbirth occur annually, as reported by the World Health Organization (WHO). One prominent cause is complicated obstructed labor, also known as labor dystocia. This condition arises when the baby fails to navigate the birth canal despite normal uterine contractions. Therefore, understanding this complex physiological process is essential for improving diagnosis, optimizing clinical interventions, and defining predictive and preventive strategies. Currently, due to the complexity of experimental protocols and associated ethical issues, computational modeling and simulation of childbirth have emerged as the most promising solutions to achieve these objectives. However, it is crucial to quantify the significant influence of inherent uncertainties in the parameters and behaviors of the human pelvic system and their propagation through simulations to establish reliable indicators for clinical decision-making. Specifically, epistemic uncertainties due to lack of knowledge and aleatoric uncertainties due to intrinsic variability in physical domain geometries, material properties, and loads are often not fully understood and are frequently overlooked in current literature on childbirth computational modeling and simulation.This PhD thesis addresses three original contributions aimed at overcoming these challenges: 1) development and evaluation of a computational workflow for the uncertainty quantification of hyperelastic properties of the soft tissue using precise and imprecise probabilities; 2) extrapolation of the developed protocol for the uncertainty quantification of the active uterine contraction during the second stage of labor simulation; and 3) development and evaluation of a fetus descent simulation with the active uterine contraction using MRI-based observations and associated uncertainty quantification process.This thesis pays the way to a more reliable childbirth modeling and simulation under passive and active uterine contractions. In fact, the developed computational protocols could be extrapolated into a patient-specific modeling and simulation to identify the risk factors and associated strategies for vaginal delivery complications in a straightforward manner. Finally, the investigation of stochastic finite element formulation will allow to improve the computational cost for the uncertainty quantification process

Normal labour is a process of spontaneous expulsion of the fetus, placenta, and membranes at term. This process is initiated by complex endocrine mechanisms that cause uterine contractions which lead to effacement and dilatation of the cervix and descent of the fetus, resulting in delivery. About 10% of women go into labour in the preterm period. The progress is dependent on uterine contractions (power), the size and presentation of the fetus (passenger), and the size of the pelvis (passage). For ease of management, the observed labour is artificially divided into three stages. The partogram is used to manage labour and is where maternal and fetal observations can be plotted in addition to cervical dilatation and descent of the presenting part. The value of active management is still debated but has been adapted in routine practice. More research is needed to decide the best management of labour to optimize the maternal and fetal outcomes.

Primary postpartum hemorrhage (PPH) is one of the leading causes of maternal morbidity and mortality worldwide. The most common cause of primary PPH is uterine atony. Various uterotonics have been used over the years for the prevention of PPH. Oxytocin, Ergometrine, Misoprostol, and Carboprost have been extensively studied. Recently, Carbetocin, an analog of Oxytocin has been added to the armamentarium of postpartum hemorrhage. However, the optimal route and dose of these drugs are still being studied. Oxytocin induces superior myometrial contractions when compared with Ergometrine, Carboprost and Misoprostol. The effect of Oxytocin is reduced in myometrium of women with Oxytocin-augmented labor; however, it is still superior to the other uterotonics. Although the value of universal use of uterotonics to reduce postpartum hemorrhage after vaginal birth has been well established, their value in cesarean section has received little attention. It has been assumed that the benefits of oxytocics observed at vaginal birth also apply to cesarean section. The route of Oxytocin has been studied by various researchers. Intravenous (IV) infusion of Oxytocin has been preferred during cesarean section as an IV line would have been already secured and it has faster plasma peak concentration as in comparison to the Intramuscular (IM) route. Though IV bolus Oxytocin has been associated with a faster peak plasma concentration of Oxytocin, faster uterine contraction; it also has been associated with sudden hypotension. Carbetocin is also another promising drug. It has been prioritized due to its heat stable and long-acting properties. It also reduces the need for infusions. It is still an expensive drug in many countries. Carbetocin is administered as 100 mcg IM/IV/IV infusion. The dose in elective cesarean may be less as shown in some studies. Misoprostol by oral route has been recommended by WHO at 400–600 mcg in places where Oxytocin cannot be administered. Syntometrine has lesser blood loss compared to Oxytocin alone.

The posterior pituitary produces arginine vasopressin, which has a key role in fluid homeostasis, and oxytocin, which stimulates uterine contraction during birth and ejection of milk during lactation. Cranial diabetes insipidus is the passage of large volumes of dilute urine due to vasopressin deficient synthesis and/or release. The most common cause is lesions of the neurohypophysis or the hypothalamic median eminence damaging the magnocellular neurons. MRI of the neurohypophysis is required to delineate the cause. Mild polyuria can be managed simply by ensuring adequate fluid intake; treatment with the long-acting vasopressin analogue, desmopressin is used for more severe cases. The syndrome of inappropriate antidiuresis is diagnosed when there is hyponatraemia with hypotonic plasma, inappropriate urine osmolality, and urinary sodium more than 20 mmol/litre, together with no evidence of volume overload or hypovolaemia, and normal renal, adrenal, and thyroid function.

The posterior pituitary produces arginine vasopressin, which has a key role in fluid homeostasis, and oxytocin, which stimulates uterine contraction during birth and ejection of milk during lactation. Cranial diabetes insipidus is the passage of large volumes (>3 litres/24 h) of dilute urine (osmolality<300 mOsm/kg) due to vasopressin deficiency, and most commonly occurs as a consequence of trauma or tumour affecting the posterior pituitary. Diagnosed by a water deprivation test revealing urine osmolality less than 300 mOsml/kg with concurrent plasma osmolality more than 290 mOsml/kg after dehydration, with urine osmolality rising to more than 750 mOsml/kg after desmopressin. MRI of the neurohypophysis is required to delineate the cause. Mild polyuria can be managed simply by ensuring adequate fluid intake; treatment with the long-acting vasopressin analogue, desmopressin (desamino, D-8 arginine vasopressin; DDAVP), is used for more severe cases....

Abstract Tocolytic agents are agents that inhibit uterine contraction and allow enough time for corticosteroids to help with lung maturation. They are administered in cases of premature labor between the 22nd and 34th weeks of gestational age. They are divided into betamimetics, calcium channel blockers, cyclooxygenase inhibitors, and magnesium sulfate. Betamimetics can be used for a short period of time; their prolonged use is not recommended due to extensive side effects, including maternal death. They are associated with pulmonary edema, tachycardia, arrhythmias, hyperglycemia, and hypokalemia. Calcium channel blockers are more beneficial than β-adrenergic agents for prolongation of pregnancy, neonatal morbidity, and maternal side effects. Magnesium sulfate is not effective in delaying labor, and it does not have an advantage over other tocolytic agents when it comes to neonatal and maternal outcomes, as it shown in a Cochrane review. However, evidence suggests that magnesium sulfate reduces the severity of cerebral palsy in surviving infants if administered when the birth is anticipated before 32 weeks of gestation. It does prolong the action of depolarizing and nondepolarizing muscle relaxant and can have serious side effects if overdosed.

Preterm labor is the leading cause of neonatal mortality and accounts for 70% of the total cost of neonatal health care. Premature softening of the cervix has been identified as one of the primary causes of preterm labor. As the biochemistry of the cervix is distinct between the proximal and distal portions, the objective of this study was to determine the viscoelastic properties of these portions in mid-pregnancy (Day 15–16) relative to virgin Long-Evans rats. This will serve to establish baseline data for future studies that will aim to induce preterm labor in this model. The cervix was divided into distal and proximal portions that were tested independently. Each portion was tested in unconfined compression to 20% strain and held for 4 minutes followed by a recovery period of 30 minutes. The stress-relaxation response was modeled using the quasi-linear viscoelastic (QLV) theory developed by Professor Fung (1972). The parameters governing the viscous response, C, τ1 and τ2, were found to be significantly different between virgin and pregnant tissues in distal portions; however τ2 was the only viscous parameter found to be significantly different for the proximal portion (p<0.05). These results show an increased magnitude of the viscous response with more rapid relaxation for the pregnant cervix. Future studies will evaluate the cervix both postpartum and upon induction of preterm labor. Additionally, contractile and biochemical assays will be used to correlate these changes in passive behavior to active properties and tissue constituents.

The cervix plays a critical role during pregnancy, acting as a mechanical barrier to keep the fetus inside the uterus until term. In a normal pregnancy, it is hypothesized that the cervix gradually softens until uterine contractions occur. At this point, the cervix dramatically ripens and dilates for delivery. Similar to other collagenous tissues, the extracellular matrix (ECM) is the load-bearing component of cervical tissue. It is composed mainly of a cross-linked network of fibril forming collagen, types I and III, embedded in a viscous proteoglycan ground substance. Studies conducted on animal models suggest that during normal maturation, a shift in ECM components facilitate cervical softening. However, quantitative cervical softness measurements (i.e. material properties) of these previous studies are ill-defined, limiting the comparative ability of the outcome values. Therefore, our goal is to quantify sensitive and specific time-dependent material properties utilizing mouse models of normal and abnormal pregnancy. Our aim is to discern the role of ECM maintenance in cervical softening.