Arrest of mouse preterm labor until term delivery by combination therapy with atosiban and mundulone, a natural product with tocolytic efficacy.

There is a lack of FDA-approved tocolytics for the management of preterm labor (PL). In prior drug discovery efforts, we identified mundulone and mundulone acetate (MA) as inhibitors of in vitro intracellular Ca2+-regulated myometrial contractility. In this study, we probed the tocolytic potential of these compounds using human myometrial samples and a mouse model of preterm birth. In a phenotypic assay, mundulone displayed greater efficacy, while MA showed greater potency and uterine-selectivity in the inhibition of intracellular-Ca2+ mobilization. Cell viability assays revealed that MA was significantly less cytotoxic. Organ bath and vessel myography studies showed that only mundulone exerted inhibition of myometrial contractions and that neither compounds affected vasoreactivity of ductus arteriosus. A high-throughput combination screen identified that mundulone exhibits synergism with two clinical-tocolytics (atosiban and nifedipine), and MA displayed synergistic efficacy with nifedipine. Of these combinations, mundulone+atosiban demonstrated a significant improvement in the in vitro therapeutic index compared to mundulone alone. The ex vivo and in vivo synergism of mundulone+atosiban was substantiated, yielding greater tocolytic efficacy and potency on myometrial tissue and reduced preterm birth rates in a mouse model of PL compared to each single agent. Treatment with mundulone after mifepristone administration dose-dependently delayed the timing of delivery. Importantly, mundulone+atosiban permitted long-term management of PL, allowing 71% dams to deliver viable pups at term (>day 19, 4-5 days post-mifepristone exposure) without visible maternal and fetal consequences. Collectively, these studies provide a strong foundation for the development of mundulone as a single or combination tocolytic for management of PL.

Synthesis of 5- and 7-hydroxy indolizidin-2-one prostaglandin-F2α modulators and activity on myometrial contractility towards development of agents for delaying preterm birth.

In pursuit of more effective-labor delaying tocolytic agents, the prostaglandin F2α (PGF2α) receptor (FP) modulator PDC113.824 [(6S)-2] represents a potent lead for developing therapy to treat preterm birth. Derivatives of FP modulator (6S)-2 were synthesized, possessing respectively 5- and 7-hydroxyl groups on the indolizidin-2-one amino acid (I2 aa) residue. The effects of the alcohol substituents were examined in a PGF2α-induced myometrial contraction assay. Based on knowledge of dihedral angle values of model I2 aa peptides from X-ray analyses, the results of the study indicate respectively encouraging and limited potential for creating improved tocolytic agents by modifications at the 5- and 7-positions.

Combined uterorelaxant effect of magnesium sulfate and terbutaline: Studies on late pregnant rat uteri in vitro and in vivo.

INTRODUCTION: Preterm delivery and its complications are among the biggest challenges and health risks in obstetrical practice. Several tocolytic agents are used in clinical practice, although the efficacy and side effect profiles of these drugs are not satisfying. The aim of this study was to investigate the uterus relaxant effect of the coadministration of ß2 -mimetic terbutaline and magnesium sulfate (MgSO4 ) in an isolated organ bath and to perform in vivo smooth muscle electromyographic (SMEMG) studies in pregnant rats. In addition, we also investigated whether the tachycardia-inducing effect of terbutaline can be reduced by the presence of magnesium, due to the opposite heart rate modifying effects of the two agents. MATERIAL AND METHODS: In the isolated organ bath studies, rhythmic contractions of 22-day- pregnant Sprague-Dawley rats were stimulated with KCl, and cumulative dose-response curves were constructed in the presence of MgSO4 or terbutaline. The uterus-relaxing effects of terbutaline were also investigated in the presence of MgSO4 in both normal buffer and Ca2+ -poor buffer. The in vivo SMEMG studies were carried out under anesthesia with the subcutaneous implantation of an electrode pair. The animals were treated with MgSO4 or terbutaline alone or in combination in a cumulative bolus injection. The implanted electrode pair also detected the heart rate. RESULTS: Both MgSO4 and terbutaline reduced uterine contractions in vitro and in vivo, furthermore, the administration of a small dose of MgSO4 significantly enhanced the relaxant effect of terbutaline, especially in the lower range. However, in Ca2+ -poor environment, MgSO4 was not able to increase the effect of terbutaline, indicating the role of MgSO4 as a Ca2+ channel blocker. In the cardiovascular studies, MgSO4 significantly decreased the tachycardia-inducing effect of terbutaline in late pregnant rats. CONCLUSIONS: The combined application of MgSO4 and terbutaline may have clinical significance in tocolysis, which must be confirmed in clinical trials. Furthermore, MgSO4 could substantially reduce the tachycardia-inducing side effect of terbutaline.

Novel Tocolytic Strategy: Modulating Cx43 Activity by S-Nitrosation.

Currently available tocolytics are ineffective at significantly delaying preterm birth. This is due in part to our failure to better understand the mechanisms that drive spontaneous preterm labor (sPTL). Cyclic nucleotides are not the primary contributors to myometrial quiescence, but instead nitric oxide (NO)-mediated protein S-nitrosation (SNO) is integral to the relaxation of the tissue. Connexin-43 (Cx43), a myometrial "contractile-associated protein" that functions as either a gap junction channel or an hemichannel (HC), was the focus of this study. Protein analysis determined that Cx43 is downregulated in sPTL myometrium. Furthermore, Cx43 is S-nitrosated by NO, which correlates with an increase of phosphorylated Cx43 at serine 368 (Cx43-pS368 -gap junction inhibition) as well as an increase in the HC open-state probability (quiescence). Pharmacologic inhibition of Cx43 with 18ß-glycyrrhetinic acid (18ß-GA) exhibits a negative inotropic effect on the myometrium in a dose-dependent manner, as does administration of nebivolol, an NO synthase activator that increases total protein SNOs. When 18ß-GA and nebivolol were coadministered at their IC50 values, the effect on contractile dynamics was additive and all but eliminated contractions. The development of new tocolytics demands a better understanding of the underlying mechanisms of sPTL. Here it has been shown that 18ß-GA and nebivolol leverage dysregulated pathways in the myometrium, resulting in a novel approach for the treatment of sPTL. SIGNIFICANCE STATEMENT: Although there are many known causes of preterm labor (PTL), the mechanisms of "spontaneous" PTL (sPTL) remain obfuscated, which is why treating this condition is so challenging. Here we have identified that connexin-43 (Cx43), an important contractile-associated protein, is dysregulated in sPTL myometrium and that the pharmacologic inhibition of Cx43 and its S-nitrosation with 18ß-glycyrrhetinic acid and nebivolol, respectively, significantly blunts contraction in human myometrial tissue, presenting a novel approach to tocolysis that leverages maladjusted pathways in women who experience sPTL.

Tocolytic effect of the monoterpenic phenol isomer, carvacrol, on the pregnant rat uterus.

Despite the wide application of carvacrol (CAR) in different biological and medical areas, there is still insufficient electrophysiological data on the mechanisms of action of CAR, particularly in the pregnant uterine function. The aim of this study was to evaluate the in vitro tocolytic effect of CAR on the contractility of isolated pregnant rat uterus in the presence of a calcium channel antagonist (nifedipine) and a cyclooxygenase inhibitor (indomethacin). The uteri were isolated from pregnant Wistar rats at 16-18 days of pregnancy and suspended in an isolated organ bath chamber containing a Ringer's physiological solution and aerated with 95% O2and 5% CO2. Samples were used in functional tests to evaluate the inhibitory effect of CAR at increasing concentrations on the rhythmic spontaneous, oxytocin-induced phasic, K+-induced tonic, and Ca2+-induced contractions. The differences in inhibitory concentration-50 and Emaxamong the compounds were determined using the one-way ANOVA followed by a post hoc Student-Newman-Keuls or Bonferroni test, in all casesP < 0.05 was considered statistically significant. Nifedipine was used as positive controls where required. CAR caused a significant concentration-dependent inhibition of the uterine contractions induced by the pharmaco- and electro-mechanic stimuli. We showed that the inhibitory effects of CAR depends on the type of muscle contraction stimuli, and that it acts stronger in spontaneous rhythmic activity and in contractions of isolated rat uterus induced by Ca2+. Nifedipine was more potent than CAR and indomethacin on the uterine contractility (P < 0.05), but none of them was more effective than nifedipine. Therefore, the tocolytic effect induced by CAR was associated with the blockade of the calcium channels in the pregnant rat uterus. This property placed CAR as a potentially safe and effective adjuvant agent in cases of preterm labor, an area of pharmacological treatment that requires urgent improvement.

Intramuscular 17α-hydroxyprogesterone caproate to decrease preterm delivery in women with placenta praevia: a randomised controlled trial.

We tested the hypothesis that 17α-hydroxyprogesterone caproate (17α-OHP-C) may decrease preterm delivery (PTD) in women with placenta praevia. This was a randomised controlled trial included 114 women with placenta praevia (between 24 and 28 weeks). They were randomly assigned to group I (17α-OHP-C) who received weekly injection of 17α-OHP-C (250 mg/IM) till completing 37 weeks' gestation or group II (Non 17α-OHP-C). The percentage of placenta praevia patients went into PTD in the 17α-OHP-C group was significantly less in comparison to the PTD in the Non 17α-OHP-C group (∼37% vs. 63.5%, p = .004). Furthermore, the mean gestational age was significantly longer (36.7 ± 0.7 vs. 34.9 ± 1.2 weeks, p < .000), the mean number of bleeding attacks was significantly less and the mean birth weight was significantly higher (2841 ± 159 vs. 2561 ± 168 g, p < .000). In conclusion, maintenance tocolysis with intramuscular 17α-OHP-C in placenta praevia women appears beneficial in decreasing the number of bleeding attacks, the percentage of PTD and the neonatal ICU admission.IMPACT STATEMENTWhat is already known on this subject? Over the last two decades, a large number of studies indicated that placenta praevia is a major risk factor for preterm labour and prematurity with its neonatal complications. Increasing caesarean section rates had proportionally increased the incidence of placenta praevia.What do the results of this study add? Up to now, the effective and safe tocolytic agent among these patients is not established. The results of this study (prospective, randomised and controlled with calculated sample size) added a considerable support for hydroxyprogesterone caproate as an effective, safe and cheap tocolytic agent with excellent patient compliance.What are the implications of these findings for clinical practice and/or further research? Our findings may prompt researchers to conduct a large multicentre study to evaluate the prophylactic use of hydroxyprogesterone caproate to decrease preterm labour due to placenta praevia.

Effect of betamethasone, indomethacin and fenoterol on neonatal and maternal mononuclear cells stimulated with Escherichia coli.

Despite considerable progress in the field of perinatal care, infectious diseases, especially when caused by gram negative bacteria, remain a major reason for neonatal morbidity and mortality. Notably infants born prematurely and those with very low birth weight are at risk due to their immature and deficient immune system and their prolonged hospitalization which promotes nosocomial infections. In case of impending preterm birth, betamethasone is given to induce lung maturation and tocolytic agents like indomethacin or fenoterol are administered to suppress premature labor. The aim of this study was to analyze the effects of these drugs on the immune system of mothers and neonates. Therefore, mononuclear cells from cord blood and peripheral maternal blood were stimulated with Escherichia coli and incubated with betamethasone, indomethacin and fenoterol. Subsequently the effect of the treatment on cytokine production was determined. Betamethasone alone and in combination with tocolytic agents inhibited the production of pro- and anti-inflammatory cytokines. Not only does betamethasone dampen the immune response by reducing the production of cytokines, it also has a variety of other detrimental short- and long-term effects on the neonate. In conclusion we would recommend using biological markers to determine if premature labor actually leads to preterm birth and subsequently administer betamethasone only to mothers giving birth prematurely.

Effect of dual tocolysis with fenoterol and atosiban in human myometrium.

Objectives To measure the tocolytic effect of the combination of the oxytocin receptor antagonist atosiban with the ß-mimetic agent fenoterol on human myometrium of pregnant women. Methods An in vitro study of contractility in human myometrium at the Laboratory of the Department of Obstetrics, University Hospital of Zürich, Switzerland, was performed. Thirty-six human myometrial biopsies were obtained during elective caesarean sections of singleton pregnancies at term. Tissue samples were exposed to atosiban, fenoterol and the combination of atosiban with fenoterol. Contractility was measured as area under the curve during 30 min of spontaneous contractions. The effect of treatment was expressed as the percentage of change from basal activity during 30 min of exposure. Differences were calculated using a paired Wilcoxon signed-rank test. An additive effect of dual tocolysis was assumed when no significant difference was detected between the observed and expected inhibition of dual tocolysis. When inhibition was greater or lower than expected, the dual combination was characterised as "synergistic" or "antagonistic", respectively. Results Atosiban and fenoterol alone suppressed contractions by a median of 43.2% and 29.8%, respectively. The combination of atosiban plus fenoterol was measured at a level of 67.3% inhibition. There was no significant difference in the expected (63.2%) and observed inhibition effect of dual tocolysis (P=0.945). Conclusion This study demonstrated an additive effect of dual tocolysis of atosiban and fenoterol on human myometrium in vitro, but no synergistic or antagonistic effect.

Bryophyllum pinnatum enhances the inhibitory effect of atosiban and nifedipine on human myometrial contractility: an in vitro study.

BACKGROUND: The herbal medicine Bryophyllum pinnatum has been used as a tocolytic agent in anthroposophic medicine and, recently, in conventional settings alone or as an add-on medication with tocolytic agents such as atosiban or nifedipine. We wanted to compare the inhibitory effect of atosiban and nifedipine on human myometrial contractility in vitro in the absence and in the presence of B. pinnatum press juice (BPJ). METHODS: Myometrium biopsies were collected during elective Caesarean sections. Myometrial strips were placed under tension into an organ bath and allowed to contract spontaneously. Test substances alone and at concentrations known to moderately affect contractility in this setup, or in combination, were added to the organ bath, and contractility was recorded throughout the experiments. Changes in the strength (measured as area under the curve (AUC) and amplitude) and frequency of contractions after the addition of all test substances were determined. Cell viability assays were performed with the human myometrium hTERT-C3 and PHM1-41 cell lines. RESULTS: BPJ (2.5 µg/mL), atosiban (0.27 µg/mL), and nifedipine (3 ng/mL), moderately reduced the strength of spontaneous myometrium contractions. When BPJ was added together with atosiban or nifedipine, inhibition of contraction strength was significantly higher than with the tocolytics alone (p = 0.03 and p < 0.001, respectively). In the case of AUC, BPJ plus atosiban promoted a decrease to 48.8 ± 6.3% of initial, whereas BPJ and atosiban alone lowered it to 70.9 ± 4.7% and to 80.9 ± 4.1% of initial, respectively. Also in the case of AUC, BPJ plus nifedipine promoted a decrease to 39.9 ± 4.6% of initial, at the same time that BPJ and nifedipine alone lowered it to 78.9 ± 3.8% and 71.0 ± 3.4% of initial. Amplitude data supported those AUC data. The inhibitory effects of BPJ plus atosiban and of BPJ plus nifedipine on contractions strength were concentration-dependent. None of the test substances, alone or in combination, decreased myometrial cell viability. CONCLUSIONS: BPJ enhances the inhibitory effect of atosiban and nifedipine on the strength of myometrial contractions, without affecting myometrium tissue or cell viability. The combination treatment of BPJ with atosiban or nifedipine has therapeutic potential.

Antenatal Magnesium Sulfate Exposure and Ponderal Index in Preterm Infants.

OBJECTIVE: Antenatal magnesium sulfate (MgSO4) is known to affect the central nervous system of preterm infants, and there is biologic rationale for influence on other phenotypes. This study investigated the effect of MgSO4 exposure on the trajectory of ponderal index (PI, kg/m3) from birth to 2 years of age. STUDY DESIGN: A secondary analysis of a U.S. randomized controlled trial investigating MgSO4 versus placebo administration among women at high risk for preterm delivery was performed. Multivariable logistic regression was used to assess the relationship between PI from birth to 2 years of age and exposure to MgSO4 versus placebo. RESULTS: There was a larger decrement in PI from birth to 2 years of age in infants exposed to MgSO4 compared with placebo (p = 0.032). There was a statistically significant one-way interaction between newborn sex and treatment group (p = 0.019). Change in PI in males exhibited a greater decrement in those exposed to MgSO4 versus placebo (p = 0.227), whereas female infants exposed to MgSO4 had a smaller decrement (p = 0.04). CONCLUSION: MgSO4 exposure in preterm infants is associated with a larger decrease in PI from birth to 2 years of age. In addition, the direction of effect of MgSO4 on the change in PI over the first 2 years of life is different by sex.

In which preterm labor-patients is intravenous maintenance tocolysis effective?

AIM: We evaluated whether maintenance tocolysis (intravenous ritodrine hydrochloride and/or magnesium sulfate) was effective in cases of spontaneous preterm labor with intact membranes. METHODS: One hundred and thirty preterm labor patients who reached 36 weeks of gestation by maintenance tocolysis were selected. Immediate delivery (ID) after ceasing maintenance tocolysis was defined as an 'effective case'. The correlated factors between ID and no immediate delivery (NID) were statistically analyzed. RESULTS: Thirty-six patients delivered < two days after ceasing maintenance tocolysis (27.7%) and were defined as effective cases. Multiple logistic regression analysis revealed that amniotic fluid interleukin-8 at admission (≥ 2.3 ng/mL; odds ratio [OR] 5.6, 95% confidence interval [CI] 2.1-17.6; P < 0.001), pre-pregnancy body mass index (≤ 21.4; OR 5.3, 95% CI 2.0-16.2; P < 0.001) and cerclage (OR 3.6, 95% CI 1.1-11.8; P = 0.028) were independent factors correlated with ID (< 2 days). CONCLUSION: Maintenance tocolysis may be effective in limited cases with mild intra-amniotic inflammation, in lean women and in cerclage cases. Maintenance tocolysis should be ceased in cases without these clinical factors when clinical symptoms disappear.

Uterine electrical activity, oxytocin and labor: translating electrical into mechanical.

PURPOSE: Uterine activity plays a crucial role in labor, especially when utero-tonic materials are administered. We aimed to determine the electrical responsiveness of the uterine musculature to labor augmentation with oxytocin using electrical uterine myography (EUM) technology, and to assess whether the kinetics of the EUM device may serve as a predictor for successful vaginal delivery. METHODS: EUM prospectively measured electrical uterine activity in women with singleton gestations at term (≥ 37 + 0 weeks) undergoing labor augmentation by oxytocin administration. The results were reported as the EUM index, which represented the mean electrical activity in 10-min intervals and measured in units of microwatt per second (mW/s). Measurements were performed at least 30 min before oxytocin initiation and until at least four contractions per 10 min were recorded by standard tocodynamometry. The delta EUM index was defined as the difference between the mean EUM index before and after the initiation of oxytocin. RESULTS: The mean EUM index increased significantly during oxytocin augmentation in all the parturients (P < 0.001). Mean and minimum (but not maximum) uterine electrical activity during oxytocin infusion correlated with the baseline uterine activity. The delta EUM index was not significantly affected by demographic or obstetric parameters. There was no correlation between the delta EUM index and time to delivery or the mean EUM index during oxytocin administration and time to delivery. CONCLUSIONS: Uterine electrical activity as evaluated by EUM is significantly intensified following oxytocin administration, regardless of obstetrical characteristics, and is correlated with the baseline uterine electrical activity prior to oxytocin infusion.

Phorbol 12,13-dibutyrate-induced protein kinase C activation triggers sustained contracture in human myometrium in vitro.

BACKGROUND: Although physiologic transition from rhythmic contractions to uterine retraction postpartum remains a poorly understood process, it has been shown that the latter is essential in the prevention of hemorrhage and its negative consequences. OBJECTIVE: To investigate the transition from oscillatory contractions to tonic contracture in human myometrium after delivery, a mechanism purported to facilitate postpartum hemostasis. Protein kinase C (PKC) plays a key regulatory role in human uterine contractions because it can prevent dephosphorylation of regulatory proteins and sensitize the contractile machinery to low Ca2+. Thus, activation of PKC by phorbol 12,13-dibutyrate (PDBu) may act as a strong uterotonic agent. STUDY DESIGN: Uterine biopsies were obtained from consenting women undergoing elective caesarian delivery at term without labor (N = 19). Isometric tension measurements were performed on uterine strips (n = 114). The amplitudes and area under the curve of phasic contractions and tonic responses were measured and compared. A total of 1 µM PDBu was added to the isolated organ baths, and maximal tension of the uterine contracture was determined in the absence and presence of either 1 µM of staurosporine, 100 nM nifedipine, or 10 µM cyclopiazonic acid to assess the role of PKC and calcium sensitivity on uterine contractility. RESULTS: On the addition of PDBu on either basal or oxytocin-induced activity, consistent contractures were obtained concomitant with complete inhibition of phasic contractions. After a 30-minute incubation period, the mean amplitude of the PDBu-induced tone represented 65.3% of the amplitude of spontaneous contraction. Staurosporine, a protein kinase inhibitor, induced a 91.9% inhibition of PDBu contractures, a process not affected by nifedipine or cyclopiazonic acid, thus indicating that this mechanism is largely Ca2+ independent. CONCLUSION: Pharmacologic activation of PKC leads to a significant contracture of the myometrium. Together, these data suggest that the up-regulation of PKC plays a physiologic role in the modulation of uterine contracture after delivery. A switch from phasic to strong tonic contractions potentially may facilitate postpartum hemostasis.

Effect of magnesium sulfate on oxytocin-induced contractility in human myometrium: an in vitro study.

PURPOSE: The purpose of this study was to determine the contractile patterns induced by oxytocin in myometrium exposed to magnesium sulfate (MgSO4). We hypothesized that MgSO4 pretreatment would reduce oxytocin-induced myometrial contractions in both oxytocin-naïve and oxytocin-desensitized myometrium. METHODS: In this prospective in vitro study, myometrial samples were obtained from 26 women undergoing elective Cesarean deliveries. Samples were divided into six groups. Four groups were apportioned to no pretreatment (control group), oxytocin 10-5 M pretreatment (desensitization group), MgSO4 3.5 mM pretreatment, and MgSO4 3.5 mM + oxytocin 10-5M pretreatment. This was followed by dose-response testing to oxytocin 10-10 to 10-5M in all four groups. Two additional groups included MgSO4 3.5 mM pretreatment and MgSO4 3.5 mM + oxytocin 10-5 M pretreatment, followed by dose-response testing to oxytocin along with MgSO4 3.5 mM. The outcomes were motility index (MI), as defined by the amplitude (g) × frequency of myometrial contractions (c) over ten minutes, and area under the curve (AUC). RESULTS: In oxytocin-naïve myometrium, the mean (standard error [SE]) MI was not affected by MgSO4 pretreatment [3.31 (0.20) √g⋅c/10 min] as compared with control (P = 0.88), even when MgSO4 was continued during dose-response testing [2.50 (0.19) √g⋅c/10 min; P = 0.41]. In the oxytocin-desensitized model, mean (SE) MI was not affected by MgSO4 pretreatment [2.60 (0.21) √g⋅c/10 min; P = 0.68], but when MgSO4 was continued during the dose-response period, the MI was significantly reduced compared with control [1.89 (0.13) √g⋅c/10 min; P < 0.001]. The results for AUC were similar to MI, except for a significant reduction in oxytocin-naïve myometrium when MgSO4 was continued during dose-response testing (P = 0.02). CONCLUSION: Magnesium sulfate pretreatment does not impair oxytocin-induced myometrial contractility in oxytocin-naïve or desensitized myometrium unless it is continued during oxytocin dose-response testing. These results suggest that its tocolytic effect is likely dependent on an extracellular mechanism. The study was registered with ClinicalTrials.gov, number NCT02647268.

Nifedipine increases fetoplacental perfusion.

AIM: Our aim is to evaluate the effect of nifedipine on fetoplacental hemodynamic parameters. METHODS: A retrospective study was conducted at a tertiary center with 30 patients for whom nifedipine treatment was used as a tocolytic therapy for preterm labor. Initiation of this treatment was at 31.6±2.5 weeks of gestation. We combined the pulse Doppler imaging parameters with grayscale imaging via the Bernoulli theorem, which is called the "continuity equation", to get the fetoplacental perfusion (FPP). Evaluated parameters were the resistance index (RI), the pulsatility index (PI), systole/diastole ratios (S/D), the velocity-time integral of the umbilical artery (VTI), the radius of the umbilical artery, the peak systolic velocity and the mean pressure gradient in the umbilical artery. From these parameters, the FPP was acquired. RESULTS: We found that the RI, the PI and the S/D ratio did not change after treatment with nifedipine. The mean pressure gradient, the VTI and the peak systolic velocity increased after treatment with nifedipine. Nifedipine increases FPP from 166±73.81 beat.cm3/min to 220±83.3 beat.cm3/min. DISCUSSION: Although nifedipine had no effect on the PI, the RI or the S/D, it increased the mean pressure gradient, the VTI and FPP.

Introduction of management protocol for early-onset severe pre-eclampsia.

AIM: This quality Improvement study evaluated the applicability of our protocol for early-onset severe pre-eclampsia, prepared in April 2013. METHODS: We collected data from all women with early-onset severe pre-eclampsia treated at our hospital between March 2008 and August 2015. Neonatal and maternal outcomes were compared between protocol-based (n = 17) and non-protocol-based management groups (n = 28). RESULTS: The latency period was significantly longer in the protocol-based than in the non-protocol-based group (21.9 ± 3.7 vs 11.0 ± 2.9 days). Gestational age at delivery was significantly more advanced in the protocol-based than in the non-protocol-based group (31.4 ± 0.6 vs 29.8 ± 0.4 weeks). Serious neonatal complications were significantly less prevalent in the protocol-based than in the non-protocol-based group (26% vs 79%). Among the protocol components, magnesium sulfate use was the only independent factor contributing to the absence of serious neonatal complications. The percentages of women exhibiting persistent proteinuria or hypertension at one, two and three months post-partum were similar between the groups. CONCLUSIONS: Strict adherence to our protocol improved neonatal outcomes without affecting maternal prognosis. Routine use of magnesium sulfate could be the most important component of the protocol.

Effect of vaginal progesterone in tocolytic therapy during preterm labor in twin pregnancies: Secondary analysis of a placebo-controlled randomized trial.

AIM: Our aim was to investigate the effect of the prophylactic use of vaginal progesterone on the latency period from the initiation of tocolytic therapy to delivery in twin pregnancies with preterm labor. METHODS: This study was a secondary analysis of a randomized, double-blind, placebo-controlled trial of twin pregnancies in mothers who were exposed to a 200 mg vaginal progesterone ovule or a placebo ovule daily from 18 to 34 weeks gestation. Patients who were administered tocolysis with Atosiban because of preterm labor were included. The latency from tocolysis to delivery, mean gestational age at delivery and the rates of delivery within 48 h and within seven days were compared between progesterone and placebo groups. RESULTS: The analysis included 27 women in the progesterone group and 30 in the placebo group. The baseline characteristics were similar between the groups. Overall, there were no differences in the latency period to delivery (17.54 ± 13.54 days and 21.58 ± 13.52 days; P = 0.289), rates of delivery within 48 h (14.8% and 6.7%; P = 0.40) or within seven days (29.64% and 23.3%; P = 0.76) or mean gestational age at delivery (32.53 ± 3.33 and 34.13 ± 2.87; P = 0.08) between the progesterone and placebo groups, respectively. CONCLUSIONS: Prophylactic use of 200 mg of vaginal progesterone does not influence the latency to delivery in women with twin pregnancies treated with tocolysis because of preterm labor.

Tocolytic action and underlying mechanism of galetin 3,6-dimethyl ether on rat uterus.

BACKGROUND: Galetin 3,6-dimethyl ether (FGAL) is a flavonoid isolated from aerial parts of Piptadenia stipulacea. Previously, FGAL was shown to inhibit both carbachol- and oxytocin-induced phasic contractions in the rat uterus, which was more potent with oxytocin. Thus, in this study, we aimed to investigate the tocolytic action mechanism of FGAL on the rat uterus. METHODS: Segments of rat uterus ileum were suspended in organ bath containing modified Locke-Ringer solution at 32 °C, bubbled with carbogen mixture under a resting tension of 1 g. Isotonic contractions were registered using kymographs and isometric contractions using force transducer. RESULTS: FGAL was more potent in relaxing uterus pre-contracted with oxytocin than with KCl. Additionally, FGAL shifted oxytocin-induced cumulative contractions curves to the right in a non-parallel manner, with Emax reduction, indicating a pseudo-irreversible noncompetitive antagonism of oxytocin receptors (OTR) or a downstream pathway target. Moreover, FGAL shifted CaCl2-induced cumulative contraction curves to the right in a non-parallel manner in depolarizing medium, nominally without Ca2+, with Emax reduction, suggesting the inhibition of Ca2+ influx through CaV. The relaxant potency of FGAL was reduced by CsCl, a non-selective K+ channel blocker, suggesting positive modulation of these channels. Furthermore, in presence of apamin, 4-aminopyridine, glibenclamide or 1 mM TEA+, the relaxant potency of FGAL was attenuated, indicating the participation of SKCa, KV, KATP and highlighting BKCa. Aminophylline, a non-selective phosphodiesterase (PDE) blocker, did not affect the FGAL relaxant potency, excluding the modulation of cyclic nucleotide PDEs pathway by FGAL. CONCLUSION: Tocolytic effect of FGAL on rat uterus occurs by pseudo-irreversible noncompetitive antagonism of OTR and activation of K+ channels, primarily BKCa, leading to calcium influx reduction through CaV.

A meta-analysis of atosiban supplementation among patients undergoing assisted reproduction.

OBJECTIVES: Evidence for the efficacy of atosiban in improving pregnancy outcomes among patients undergoing assisted reproductive technology (ART) remains inconsistent. METHODS: The PubMed, EMBASE, and CNKI databases were searched using keywords such as 'atosiban', 'infertility', and 'ART'. Studies that explored the efficacy of atosiban in the field of ART for patients with embryo transfer (ET) were included if they evaluated pregnancy outcomes. Combing using subgroups and sensitivity analysis were conducted, and risk ratios (RRs), and 95% confidence intervals (CIs) were calculated. RESULTS: Six studies were included. Atosiban treatment could improve pregnancy outcomes for all patients undergoing ET, especially for the subgroups of patients with repeated implantation failure (RIF) (implantation rate: RR = 1.806, 95% CI = 1.473-2.215; clinical pregnancy rate: RR = 1.725, 95% CI = 1.394-2.135; live birth rate: RR = 2.141, 95% CI = 1.494-3.068), as shown by the comparison with placebo or no-treatment groups. However, no statistical significance was detected in subgroups of patients undergoing their first or second ET cycle. In addition, no significant differences were observed in positive pregnancy tests, miscarriage rates, multiple pregnancy rates, or ectopic pregnancy rates. CONCLUSIONS: Supplementation with atosiban has a positive effect on ART and embryo transfer procedure, especially for women undergoing their third or more ET cycle.

Programmed cell death-1 (PD-1) and T-cell immunoglobulin mucin-3 (Tim-3) regulate CD4+ T cells to induce Type 2 helper T cell (Th2) bias at the maternal-fetal interface.

STUDY QUESTION: Are the immune regulatory molecules programmed cell death-1 (PD-1) and T-cell immunoglobulin mucin-3 (Tim-3) involved in regulating CD4+ T cell function during pregnancy? SUMMARY ANSWER: PD-1 and Tim-3 promote Type 2 helper T cell (Th2) bias and pregnancy maintenance by regulating CD4+ T cell function at the maternal-fetal interface. WHAT IS KNOWN ALREADY: The maternal CD4+ T cell response to fetal antigens is thought to be an important component of maternal-fetal tolerance during pregnancy. PD-1 and Tim-3 are important for limiting immunopathology. The co-expression of PD-1 and Tim-3 on T cells identifies a T cell subset with impaired proliferation and cytokine production. Combined blockade of Tim-3 and PD-1 could restore T cell function to the greatest degree. STUDY DESIGN, SIZE, DURATION: The expression of PD-1 and Tim-3 on CD4+ T cells was analyzed by flow cytometry, and in vitro and in vivo analyses were used to investigate the role of PD-1/Tim-3 signal in the regulation of CD4+ T cells function and pregnancy outcome. PARTICIPANTS/ MATERIALS, SETTING, METHODS: A total of 88 normal pregnant women, 37 women with recurrent spontaneous abortion, 36 normal pregnant mice and 45 abortion-prone mice were included. We measure the expression of PD-1 and Tim-3 on CD4+ T cells and their relationship to the function of CD4+ T cells and pregnancy outcome, as well as the effects of blocking PD-1 and Tim-3 pathways on decidual CD4+ T (dCD4+ T) cells during early pregnancy. MAIN RESULTS AND THE ROLE OF CHANCE: PD-1 and Tim-3, by virtue of their up-regulation on dCD4+ T cells during pregnancy, define a specific effector/memory subset of CD4+ T cells and promote Th2 bias at the maternal-fetal interface. Using in vitro and in vivo experiments, we also found that combined targeting of PD-1 and Tim-3 pathways results in decreased production of Th2-type cytokines by dCD4+ T cells and increased fetal resorption of normal pregnant murine models. Moreover, decreased PD-1 and Tim-3 on dCD4+ T cells may be associated with miscarriage. LIMITATIONS AND LIMITS OF CAUTION: Further study is required to examine the mechanism of PD-1 and Tim-3 effects on Th2 cytokine production by CD4+ T cells during pregnancy. WIDER IMPLICATIONS OF THE FINDINGS: These results have important implications for understanding the physiological mechanisms that promote maternal-fetal tolerance. Our study also indicates that targeting Tim-3 and PD-1 pathways may represent novel therapeutic strategies to prevent pregnancy loss. STUDY FUNDING/COMPETING INTERESTS: This study was supported by the National Basic Research Program of China (2015CB943300); National Nature Science Foundation of China (81490744, 91542116, 31570920, 81070537, 31171437, 81370770, 31270969, 31570920, 91542116); the Key Project of Shanghai Municipal Education Commission (14ZZ013) and the Key Project of Shanghai Basic Research from Shanghai Municipal Science and Technology Commission (12JC1401600). None of the authors have any conflict of interest to declare.