Pattern Of Uterine Contractility Research Articles

Tocodynamometric study of uterine contractions during parturition in queens.

Tocodynamometry is an approach in small animal obstetrics to diagnose initiation, progress, completion, and problems related to parturition in queens. The present study was conducted to monitor uterine contractions using tocodynamometry at full term pregnancy and during queening and to correlate uterine contractile pattern with progression of queening. Once the signs of impending parturition were noted, the pressure transducer of tocodynamometer was placed on the lateral abdomen to monitor queening. The recordings were plotted as graph of time against pressure in mmHg. Uterine contractile patterns were assessed in order to study their relation to the progression of queening. The initial uterine contractions had a baseline and peak pressures of 7-20 and 15-36.5 mmHg with mean time interval and frequency of 5.53 min and 1.91 peaks per 10 min, respectively, with mean change of amplitude of 15.35 mmHg. The progressive baseline and peak pressures of 15-32.5 and 24-62.3 mmHg increased to 20-55 and 30-89.2, respectively, with an increase in mean frequency from 3.88 to 5.25 peaks per 10 min and increase in mean change of amplitude from 25.21 to 33.87 mmHg, followed by decrease in mean time interval from 2.82 to 1.91 min in expulsive uterine contractions. Monitoring uterine contractions using tocodynamometer helps in understanding progression of queening and problems that may rise during parturition. It was observed that during queening, baseline and peak pressures of uterine contractions remain the same, irrespective of presentation of kittens at birth.

Impact of uterine contractility on quality of life of women undergoing uterine fibroid embolization

BackgroundAlthough changes in uterine contractility pattern after uterine fibroid embolization (UFE) has already been assessed by cine magnetic resonance imaging (MRI), their impact on quality of life outcomes has not been evaluated. The purpose of this study was to evaluate the impact of uterine contractility on the quality of life of women undergoing UFE measured by the Uterine Fibroid Symptom and Quality of Life questionnaire (UFS-QOL).ResultsA total of 26 patients were included. MRI scans were acquired 30–7 days before and 6 months after UFE for all patients. The UFS-QOL was applied in person on first MRI exam day and 1 year after UFE and the outcomes were analyzed according to the groups of evolution pattern of uterine contractility: Group A: Unchanged Uterine Contractility Pattern, 38%; Group B: Favorable Modified Uterine Contractility Pattern, 50%; and Group C: Loss of Uterine Contractility, 11%. All UFE patients presented a reduction in the mean score for symptoms and increase in mean scores on quality of life. All patients in this cohort presented a reduction in mean symptom score and increase in the mean score of quality of life subscales. Group A had more relevant complaints regarding their sense of self-confidence; Group B presented worse sexual function scores before UFE, which improved after UFE compared to Group A.ConclusionsSignificant improvement in symptoms, quality of life, and uterine contractility was observed after UFE in women of reproductive age with symptomatic fibroids. Functional uterine contractility seems to have a positive impact on quality of life and sexual function in this population.Level of evidenceLevel 3, Non-randomized controlled cohort/follow-up study.

Evaluation of Uterine Contractility by Magnetic Resonance Imaging in Women Undergoing Embolization of Uterine Fibroids.

To assess uterine contractility using ultrafast magnetic resonance imaging (cine MRI) before and after uterine fibroid embolization (UFE). This is a prospective study of uterine contractility in 26 patients (age 30-41years) undergoing UFE for symptomatic uterine fibroids. Cine MRI was performed before and 6months after UFE. Two radiologists evaluated uterine contractility and classified it as absent, ordered, or disordered. Patients were then grouped into three distinct patterns of progression: unchanged contractility (group A), modified contractility (B), and loss of contractility (C). These findings were then confronted with factors that might have interfered with uterine contractility pattern (uterine volume, location of dominant fibroid, fibroid/myometrium index, and fibroid necrosis pattern). Of the 26 patients, 8 (30.7%) had no contractility before the procedure, while 18 (69.2%) exhibited some form of contractility (11 [61%] ordered, 7 [39%] disordered). All 8 patients who had no contractility at baseline exhibited contractility after UFE (5 ordered, 3 disordered). Of the 11 who had ordered contractility at baseline, 9 remained ordered and 2 lost contractility after UFE. Of the 7 with disordered contractility at baseline, 1 remained disordered, 5 progressed to ordered contractility, and 1 lost contractility. Overall, 10 patients (38%) had no change in contractility after UFE (group A), 13 (50%) had a positive change (group B), and 3 (11%) lost contractility (group C). The potential interference factors assessed had no statistically significant effect in any group. In women of reproductive age with symptomatic fibroids, uterine contractility improved significantly after UFE. Level 3-non-randomized controlled cohort/follow-up study.

Feasibility of Transabdominal Electrohysterography for Analysis of Uterine Activity in Nonpregnant Women

Uterine activity plays a key role in reproduction, and altered patterns of uterine contractility have been associated with important physiopathological conditions, such as subfertility, dysmenorrhea, and endometriosis. However, there is currently no method to objectively quantify uterine contractility outside pregnancy without interfering with the spontaneous contraction pattern. Transabdominal electrohysterography has great potential as a clinical tool to characterize noninvasively uterine activity, but results of this technique in nonpregnant women are poorly documented. The purpose of this study is to investigate the feasibility of transabdominal electrohysterography in nonpregnant women. Longitudinal measurements were performed on 22 healthy women in 4 representative phases of the menstrual cycle. Twelve electrohysterogram-based indicators previously validated in pregnancy have been estimated and compared in the 4 phases of the cycle. Using the Tukey honest significance test, significant differences were defined for P values below .05. Half of the selected electrohysterogram-based indicators showed significant differences between menses and at least 1 of the other 3 phases, that is the luteal phase. Our results suggest transabdominal electrohysterography to be feasible for analysis of uterine activity in nonpregnant women. Due to the lack of a golden standard, this feasibility study is indirectly validated based on physiological observations. However, these promising results motivate further research aiming at evaluating electrohysterography as a method to improve understanding and management of dysfunctions (possibly) related to altered uterine contractility, such as infertility, endometriosis, and dysmenorrhea.

Enhanced Uterine Contractility and Stillbirth in Mice Lacking G Protein-Coupled Receptor Kinase 6 (GRK6): Implications for Oxytocin Receptor Desensitization.

Oxytocin is a potent uterotonic agent and is used clinically for induction and augmentation of labor, as well as for prevention and treatment of postpartum hemorrhage. Oxytocin increases uterine contractility by activating the oxytocin receptor (OXTR), a member of the G protein-coupled receptor family, which is prone to molecular desensitization. After oxytocin binding, the OXTR is phosphorylated by a member of the G protein-coupled receptor kinase (GRK) family, which allows for recruitment of β-arrestin, receptor internalization, and desensitization. According to previous in vitro analyses, desensitization of calcium signaling by the OXTR is mediated by GRK6. The objective of this study was to determine the role of GRK6 in mediating uterine contractility. Here, we demonstrate that uterine GRK6 levels increase in pregnancy and using a telemetry device to measure changes in uterine contractility in live mice during labor, show that mice lacking GRK6 produce a phenotype of enhanced uterine contractility during both spontaneous and oxytocin-induced labor compared with wild-type or GRK5 knockout mice. In addition, the observed enhanced contractility was associated with high rates of term stillbirth. Lastly, using a heterologous in vitro model, we show that β-arrestin recruitment to the OXTR, which is necessary for homologous OXTR desensitization, is dependent on GRK6. Our findings suggest that GRK6-mediated OXTR desensitization in labor is necessary for normal uterine contractile patterns and optimal fetal outcome.

The inwardly rectifying K+ channel KIR7.1 controls uterine excitability throughout pregnancy.

Abnormal uterine activity in pregnancy causes a range of important clinical disorders, including preterm birth, dysfunctional labour and post-partum haemorrhage. Uterine contractile patterns are controlled by the generation of complex electrical signals at the myometrial smooth muscle plasma membrane. To identify novel targets to treat conditions associated with uterine dysfunction, we undertook a genome-wide screen of potassium channels that are enriched in myometrial smooth muscle. Computational modelling identified Kir7.1 as potentially important in regulating uterine excitability during pregnancy. We demonstrate Kir7.1 current hyper-polarizes uterine myocytes and promotes quiescence during gestation. Labour is associated with a decline, but not loss, of Kir7.1 expression. Knockdown of Kir7.1 by lentiviral expression of miRNA was sufficient to increase uterine contractile force and duration significantly. Conversely, overexpression of Kir7.1 inhibited uterine contractility. Finally, we demonstrate that the Kir7.1 inhibitor VU590 as well as novel derivative compounds induces profound, long-lasting contractions in mouse and human myometrium; the activity of these inhibitors exceeds that of other uterotonic drugs. We conclude Kir7.1 regulates the transition from quiescence to contractions in the pregnant uterus and may be a target for therapies to control uterine contractility.

777: Hypothyroidism treatment modify uterine contractility pattern in vitro

777: Hypothyroidism treatment modify uterine contractility pattern in vitro

Altered Uterine Contractility Pattern in Woman Affected by Chronic Endometritis

Altered Uterine Contractility Pattern in Woman Affected by Chronic Endometritis

The Patterns of Uterine Contractility in Normal Menstruating Women: From Physiology to Pathology

The nonpregnant uterus shows uterine activity throughout the menstrual cycle. This uterine activity was detected both by single strep tissue and by using intrauterine pressure recordings in vitro and in vivo. Today, ultrasound has made it possible to study this activity with a noninvasive approach and to assess uterine contractions (UCs) in real-time movements of the uterus. Throughout the menstrual cycle, wavelike activity patterns of the reproductive organ were established. These patterns are under control of steroid hormones. Adequate UCs may provide for gamete/embryo transportation throughout the uterotubal cavities and successful embryo implantation in spontaneous and/or assisted reproduction. Inadequate UCs may produce ectopic pregnancy, miscarriages, retrograde bleeding with dysmenorrhea, and endometriosis.

Endometriosis: the consequence of neurological dysfunction?

Endometriosis describes endometrium found outside the uterine cavity and is frequently associated with clinical presentations of chronic pelvic pain, dysmenorrhoea, dyspareunia and subfertility. It was originally attributed to retrograde menstruation with endometrium passing in a reverse direction along the Fallopian tubes into the peritoneal cavity though this theory does not account for the spectrum of intrapelvic findings. Denervation followed by reinnervation in the uterine isthmus is proposed as the primary source of clinical symptoms, and, retrograde menstruation with adhesion of endometrium to injured tissue surfaces the variable laparoscopic findings. Primary sources of denervation are difficult intrapartum episodes (parous women) and persistent straining to achieve defaecation (nulliparous women). Progressive reinnervation including stromal nerve fibre proliferation, microneuroma formation and periarterial nerve fibre proliferation, takes place over five to ten years. Damage to uterine innervation interrupts normal patterns of uterine contractility, causing loss of fundocervical polarity which promotes retrograde menstruation. Ectopic endometrium may be a marker for prior tissue damage and does not contribute to the clinical symptoms – the disease may have been largely defined by an epiphenomenon.

Investigation of cervical patency and uterine appearance in domestic cats by fluoroscopy and scintigraphy.

The cervical patency of six domestic female cats was monitored under sedation by infusion of contrast medium (Omnipaque) into the cranial vagina during early oestrus, mid-oestrus, late oestrus and interoestrus or a radiopharmaceutical ((99m)Tc-HSA) during mid- and interoestrus in a non-ovulatory oestrous cycle. The transport of the contrast medium or the radiopharmaceutical through the cervix and within the uterine horns was observed under fluoroscopy and with the aid of scintigraphy. In three of the queens, transcervical transport of contrast medium was demonstrated in all stages of oestrus, in one queen during mid-oestrus, late oestrus and 1 day after oestrus, and in two queens only during late oestrus. The relations between the cervical patency to the contrast medium and the oestrous behaviour, cornification of the vaginal cells and the serum oestradiol-17beta concentration were evaluated, and a relationship was found between the cervical patency and the degree of vaginal cornification. Transcervical transport of the radiopharmaceutical was observed in three queens during mid-oestrus. When the cervix was open, hysterography under a fluoroscope and hysteroscintigraphy were performed. The fluoroscopic and scintigraphic recordings revealed the patterns of the uterine contractions during oestrus in both ascending and descending directions, and the movement of the uterine contents back and forth between the uterine horns. The hysterograms were classified according to the shape of the uterine horns and the appearance of the endometrial lining. Spiral-shaped uterine horns with a smooth inner contour were observed in two queens, and a corkscrew appearance with irregular filling defects in the uterine lumen was shown in two queens that had developed subclinical cystic endometrial hyperplasia. These findings demonstrated that fluids or particles deposited in the cranial vagina of the cat can be transported into the uterus during some stages of the oestrous cycle. The fluoroscopic and scintigraphic techniques developed in this study may be further modified to permit more detailed studies of uterine contractile patterns and sperm transport in the feline female reproductive tract. Hysterography proved useful to diagnose uterine disease. The information on cervical patency is of value also for the development of techniques for artificial insemination in this species, and should be studied also in the ovulatory cycle.

Comparison of ectopic pregnancy rates between patients undergoing embryo transfer on day 3 vs. day 5

Objective: To compare the incidence of ectopic pregnancy between patients receiving embryos at cleavage stage (day 3) or at morula/blastocyst stage (day 5) and to examine factors that may contribute to the ectopic pregnancy rate. Design: Retrospective analysis of data collected from all IVF/ET cycles at a large University-based IVF center of all IVF/ET cycles from 1996 to 2002. Materials/Methods: The protocol for extending embryo culture to day 5 (D5) for blastocyt transfer was initiated in September 1999. Only those patients with an appropriate number of good quality embryos were considered to be candidates for blastocyst transfer (Group A); otherwise embryos were transferred on day 3 (D3, Group B). Variables examined included patient age and diagnosis, baseline and peak serum estradiol (E2) levels, number of eggs retrieved, number of embryos transferred, the type of catheter used for embryo transfer, the degree of difficulty of the transfer, and the physician and embryologist handling the embryos. Pregnancy was defined by the presence of a fetal heartbeat. Chi-square and t-tests were used for statistical analysis; p <0.05 was considered significant Results: The rate of clinical pregnancy rate per transfer and the ectopic pregnancy rate per clinical pregnancy remained unchanged for patients who had D3 embryo transfers prior to (44% and 1.2%) and following (41% and 1.4%) the adoption of blastocyst protocol. Although a significantly greater proportion of ectopic pregnancies occurred after D5 transfers (Group A: 11/ 719 transfers) compared to D3 transfers (Group B: 9/ 1570 transfers, p <0.05), the incidence of ectopic pregnancy as a function of clinical pregnancies observed did not differ (Group A:11/ 426 or 2.6%; Group B: 9/ 659 or 1.4%). There was no difference between groups A and B with respect to patient age (35 ± 3 vs. 37 ± 4 yrs), baseline E2 (31 ± 17 vs. 35 ± 11 pg/ml), peak E2 (2052 ± 878 vs. 1719 ± 1136 pg/ml), number of eggs retrieved (19 ± 9 vs. 12 ± 10) and the number of embryos transferred (3 ± 1 vs. 4 ± 1). Furthermore, there was no difference between Groups A and B with respect to the physician and embryologist handling the transfer, the frequency of various diagnoses as indication for IVF including the diagnosis of pelvic factor (pelvic adhesions, endometriosis and tubal disease), the degree of difficulty of the transfer and the type of catheter used for embryo transfer. Conclusions: Although a higher rate of ectopic pregnancy per transfer was experienced with D5 compared to the conventional D3 embryo transfers, this higher ectopic rate is most likely related to the higher implantation and pregnancy rates that result from the transfer of morulae or blastocysts. Previous studies by other investigators have linked ectopic pregnancy to an aberrant uterine contractility pattern; our data suggest that IVF patients are as likely to develop such anomalous patterns on D3 as on D5. Supported by: None.

Aberrations in uterine contractile patterns in mares with delayed uterine clearance after administration of detomidine and oxytocin

An experiment was conducted to determine whether the uterotonic effects of oxytocin, a drug used to treat mares that have a delay in uterine clearance were affected by the sedative detomidine (an α 2-agonist), a drug used to treat fractious mares. An additional objective was to identify propagation patterns of uterine contractions and determine whether these patterns differed between normal mares and mares with delayed uterine clearance (DUC). Intrauterine pressure was measured in five reproductively normal mares and four mares with DUC during estrus using an 8-F Milar catheter with two discrete pressure sensors. Mares received one of three treatments in random order: detomidine (0.001 mg/kg; i.v.); detomidine followed in 10 min by oxytocin (10 IU; i.v.); and saline (0.9% NaCl 0.5 ml; i.v.) followed in 10 min by oxytocin. All treatments induced waves of contractions; however, only three mares with DUC exhibited contractions after administration of detomidine. Normal mares experienced more uterine contractions ( P<0.01) that tended to last longer ( P<0.06), and were of greater intensity ( P<0.04) than mares with delayed clearance. Administration of detomidine before oxytocin increased the number of contractions ( P<0.02) and increased the maximum intrauterine pressure in the uterine horn ( P<0.05) in normal mares as compared to response after administration of saline and oxytocin. Detomidine had no effect in mares with delayed clearance. All mares had more propagating than non-propagating uterine contractions (74±8 versus 25±8%, respectively). Normal mares exhibited a normal propagation pattern more frequently ( P<0.0001) than mares with DUC. Simultaneous ( P<0.05) and inverted ( P<0.03) contractions occurred more frequently in mares with DUC. Administration of detomidine increased the number ( P<0.01), and tended to increase the percentage ( P<0.07) of normal propagating uterine contractions in normal mares, but did not affect propagation patterns in mares with DUC. In conclusion, detomidine augmented the uterotonic effect of oxytocin in normal mares but not in mares with DUC. Data suggest that mares with DUC have a defect in myoelectrical signaling and a decrease in the contractile strength of the uterine muscle.

Contractility of the nonpregnant uterus: the follicular phase.

Recent renewed interest in uterine contractility stems from the possibility of directly visualizing uterine contractility on images generated by high-resolution ultrasound probes. During the menstrual cycle, three typical patterns of uterine contractility have been recognized. During the luteofollicular transition and early follicular phase (menses), the contractile event involves all layers of the myometrium and exerts antegrade (from fundus to cervix) expulsive forces. Characteristically, uterine contractions are often perceived by women at the time of menses, sometimes reaching the level of painful cramps (dysmenorrhea). In the late follicular phase, uterine contractility involves only the subendometrial layers of the myometrium and is never perceived by women. The primary function of uterine contractility in the late follicular phase is to facilitate the retrograde (cervix to fundus) transport of sperm towards the distal end of the fallopian tubes where fertilization normally takes place. Finally, the uterus reaches a stage of quiescence after ovulation (under the influence of progesterone) that characterizes the major part of the luteal phase. The present review summarizes our understanding of the physiological role of uterine contractility during the follicular phase and the possible implications in pathological circumstances such as endometriosis and dysmenorrhea.

Progesterone antagonist RU 486 accommodates but does not induce labour and delivery in primates.

The hormonal mechanisms of parturition in primates remain controversial. Even so, the well-known decrease of plasma progesterone concentration near term is considered by many as the 'labour inducer'. The progesterone antagonist RU 486, which blocks progesterone activity at the cellular receptor level, appears to be a useful hormonal tool by which to study this tissue. Here, we tested its capacity to induce labour and delivery. A total of 23 Cynomolgus monkeys (Macaca fascicularis), within 9-17 days of expected term, were assigned to four different protocols to study various doses, routes and regimens of RU 486 administration. Observations included uterine contractile patterns, pharmacokinetics of RU 486 in plasma and passage of RU 486 into breast milk. None of the protocols tested successfully induced labour resulting in vaginal delivery within 24 h. Instead, the data demonstrate that blockade of progesterone activity by the progesterone antagonist was not sufficient by itself to achieve parturition in these primates. Uterine myometrial contractile activity under RU 486 exposure was not sufficient to induce labour and delivery. Moreover, the progesterone antagonist concentration in breast milk was very low, indicating little passage to suckling newborn infants.

Effects of Analgesia on Labor

Uterine activity may be defined in terms of the frequency of contractions of the uterus and the pressure generated by these contractions. Most studies that report an effect of analgesia on labor are retrospective, and, if prospective, are nonrandomized. Drug effects on uterine activity and labor progress are probably dose related, but are also influenced by a myriad of other factors including, but not limited to, the mother's emotional state, degree of cervical change, uterine contractility pattern, phase of labor, and individual differences in pharmacokinetics and drug sensitivity. The latest phase of labor may be prolonged by excessive narcotic or inappropriate timing of regional analgesia. The normal active phase tends to be resistant to the inhibitory effects of the usual amount of any analgesia. A brief period of decreased uterine activity often follows institution of analgesia. This may effectually accelerate labor in some patients by decreasing maternal anxiety and serum concentrations of catecholamines. A combination of sedation epidural blockade, and subsequent oxytocin use may prove effective in correcting a dysfunctional or hyperstimulatory pattern during the active phase. The second stage of labor may be slightly prolonged by effective epidural analgesia, but this delay is not necessarily harmful as long as the fetal heart rate tracing is normal, maternal hydration is adequate, and maternal pain relief is sufficient.

The pattern of uterine contractility in normal labor

The pattern of uterine contractility in normal labor

The in vitro effect of grandiflorenic acid and zoapatle aqueous crude extract upon spontaneous contractility of the rat uterus during oestrus cycle

Montanoa tomentosa ( zoapatle) is aMexican plant popularly used for antifertility purposes and with promising characteristics for the development of a new oral contraceptive agent with uteroevacuant properties. In a previous pharmacological report we established the ambivalent myometrial response to zoapatle leaves aqueous extract (ZACE) depending on the animal species used and on the existence or absence of pregnancy. This fact could be useful in determining an appropriate medical use of zoapatle and suggests an interesting possible hormonal dependence in its mechanism of action. To elucidate the ZACE effect upon the pattern of uterine contractility in different hormonal stages, the rat uterus in vitro during oestrus cycle was studied. The aqueous crude extract of Montanoa tomentosa leaves produced different (or even opposite), effects on uterine motility during the distinct phases of the oestrus cycle in the rat. Furthermore, pure grandiflorenic acid (GA), obtained from the phytochemical work up of this plant reproduced the uterine responses induced by ZACE. The action of zoapatle is discussed in relation to hormonal stage and to a probable adrenergic mechanism involved.

Is prostaglandin F 2α involved in the increased myometrial contractility of primary dysmenorrhoea?

The concentrations of prostaglandin F 2α (PGF 2α) and E 2 (PGE 2) in menstrual fluid collected daily from 13 women with primary dysmenorrhoea and 11 matched controls, were compared with the pattern of uterine contractility during the hour following the menstrual fluid collection. The intra-uterine pressure (IUP) was measured using a micro-transducer catheter and the tracings analysed. On Day 2 the concentration of PGF 2α correlated with the peak area, but not with amplitude, duration or rate of contraction. These findings add additional support to the hypothesis that increased production of PGF 2α could contribute to the increased uterine contractility in primary dysmenorrhoea.

Uterine contractility and plasma progesterone levels in the nonpregnant woman

Thirty-three uterine contractility recordings were obtained in four nonpregnant patients, covering 16 cycles. A modification of the sponge-tip catheter method was used. Plasma progesterone concentration at the time of the recordings was measured and correlated with the contractility patterns observed. All the recordings were done in the presence of intrauterine Silastic capsules, which were empty during the first two cycles and replaced by identical capsules filled with progesterone for the next two menstrual cycles. The observed patterns of uterine contractility failed to show a consistent relation to the plasma progesterone levels or to the phase of the cycle. The local administration of progesterone via the Silastic capsules did not affect uterine contractility. Breakthrough bleeding in one patient was associated with “labor-like” contractions, which did not coincide with abdominal cramps. Strong frequent contractions were observed with the urge to urinate.