Therapy side-effects and predictive factors for preterm delivery in patients undergoing tocolysis with atosiban or ritodrine for threatened preterm labour

Management of preterm labor: Clinical practice guideline and recommendation by the WAPM-World Association of Perinatal Medicine and the PMF-Perinatal Medicine Foundation

This practice guideline follows the mission of the World Association of Perinatal Medicine in collaboration with the Perinatal Medicine Foundation, bringing together groups and individuals throughout the world, with the goal of improving the management of preterm labor. In fact, this document provides further guidance for healthcare practitioners on the appropriate use of examinations with the aim to improve the accuracy in diagnosing preterm labor and allow timely and appropriate administration of tocolytics, antenatal corticosteroids and magnesium sulphate and avoid unnecessary or excessive interventions. Therefore, it is not intended to establish a legal standard of care. This document is based on consensus among perinatal experts throughout the world in the light of scientific literature and serves as a guideline for use in clinical practice.

Nanotechnologies in Obstetrics and Cancer during Pregnancy: A Narrative Review

Nanotechnology, the art of engineering structures on a molecular level, offers the opportunity to implement new strategies for the diagnosis and management of pregnancy-related disorders. This review aims to summarize the current state of nanotechnology in obstetrics and cancer in pregnancy, focusing on existing and potential applications, and provides insights on safety and future directions. A systematic and comprehensive literature assessment was performed, querying the following databases: PubMed/Medline, Scopus, and Endbase. The databases were searched from their inception to 22 March 2022. Five independent reviewers screened the items and extracted those which were more pertinent within the scope of this review. Although nanotechnology has been on the bench for many years, most of the studies in obstetrics are preclinical. Ongoing research spans from the development of diagnostic tools, including optimized strategies to selectively confine contrast agents in the maternal bloodstream and approaches to improve diagnostics tests to be used in obstetrics, to the synthesis of innovative delivery nanosystems for therapeutic interventions. Using nanotechnology to achieve spatial and temporal control over the delivery of therapeutic agents (e.g., commonly used drugs, more recently defined formulations, or gene therapy-based approaches) offers significant advantages, including the possibility to target specific cells/tissues of interest (e.g., the maternal bloodstream, uterus wall, or fetal compartment). This characteristic of nanotechnology-driven therapy reduces side effects and the amount of therapeutic agent used. However, nanotoxicology appears to be a significant obstacle to adopting these technologies in clinical therapeutic praxis. Further research is needed in order to improve these techniques, as they have tremendous potential to improve the accuracy of the tests applied in clinical praxis. This review showed the increasing interest in nanotechnology applications in obstetrics disorders and pregnancy-related pathologies to improve the diagnostic algorithms, monitor pregnancy-related diseases, and implement new treatment strategies.

Preterm Labor: A Comprehensive Review of Guidelines on Diagnosis, Management, Prediction and Prevention

Importance

Preterm labor (PTL) is one of the most common and serious pregnancy complications associated with significant perinatal morbidity and mortality, as well as long-term neurologic impairment in the offspring.

Objective

The aim of this study was to review and compare the most recently published major guidelines on diagnosis, management, prediction, and prevention of this severe complication of pregnancy.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence (NICE), the World Health Organization, the American College of Obstetricians and Gynecologists, the New South Wales Government, and the European Association of Perinatal Medicine (EAPM) on PTL was carried out.

Results

There is a consensus among the reviewed guidelines that the diagnosis of PTL is based on clinical criteria, physical examination, measurement of cervical length (CL) with transvaginal ultrasound (TVUS) and use of biomarkers, although there is disagreement on the first-line diagnostic test. The NICE and the EAPM are in favor of TVUS CL measurement, whereas the New South Wales Government mentions that fetal fibronectin testing is the mainstay for PTL diagnosis. Moreover, there is consistency among the guidelines regarding the importance of treating PTL up to 34 weeks of gestation, to delay delivery for 48 hours, for the administration of antenatal corticosteroids, magnesium sulfate, and in utero transfer to higher care facility, although several discrepancies exist regarding the tocolytic drugs of choice and the administration of corticosteroids and magnesium sulfate after 34 and 30 gestational weeks, respectively. Routine cesarean delivery in case of PTL is unanimously not recommended. Finally, the NICE, the American College of Obstetricians and Gynecologists, and the EAPM highlight the significance of screening for PTL by TVUS CL measurement between 16 and 24 weeks of gestation and suggest the use of either vaginal progesterone or cervical cerclage for the prevention of PTL, based on specific indications. Cervical pessary is not recommended as a preventive measure.

Conclusions

Preterm labor is a significant contributor of perinatal morbidity and mortality with a substantial impact on health care systems. Thus, it seems of paramount importance to develop consistent international practice protocols for timely diagnosis and effective management of this major obstetric complication and subsequently improve pregnancy outcomes.

Acute tocolysis for intrapartum nonreassuring fetal status: how often does it prevent cesarean delivery? A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to evaluate the effectiveness of intrapartum acute tocolysis for nonreassuring fetal heart rate tracing in decreasing the incidence of cesarean delivery. Secondary outcomes included modes of delivery other than cesarean delivery, successful acute tocolysis, time-to-delivery interval, and short-term perinatal outcomes.

DATA SOURCES

Searches were performed in MEDLINE/PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials and Reviews, ClinicalTrials.gov, and the International Clinical Trials Registry Platform from the inception of each database until February 2022.

STUDY ELIGIBILITY CRITERIA

Selection criteria included randomized controlled trials of laboring patients with singleton gestations randomized to receive intrapartum acute tocolysis for nonreassuring fetal heart rate tracing, as defined by the original trial.

METHODS

All analyses were done using an intention-to-treat approach, evaluating women according to the treatment group to which they were randomly allocated in the original trials. A frequentist network-meta-analysis was performed.

RESULTS

Four randomized clinical trials were eligible, including 605 patients with nonreassuring fetal heart rate tracing and singleton gestations at gestational ages >32 weeks. The cesarean delivery rate was similar among patients managed with different types of acute tocolysis. Acute tocolysis, compared with emergency delivery, was associated with improved neonatal acid-base status (notably decreasing the prevalence of base deficit >12 mmol/L [beta-2 agonists odds ratio, 0.61; 95% confidence interval, 0.37-0.99] and the rate of neonatal intensive care unit admission [beta-2 agonists odds ratio, 0.42; 95% confidence interval, 0.22-0.78]) and with an increase in the time-to-delivery interval (beta-2 agonists mean difference, 17.62 minutes; 95% confidence interval, 15.66-19.58); there was no reduction of cesarean delivery rate, showing an increased rate with atosiban and beta-2 agonists.

CONCLUSION

The cesarean delivery rate was not reduced by acute tocolysis when used for nonreassuring fetal heart rate tracing during labor. Acute tocolysis is associated with improved short-term fetal outcomes and safely increases the time-to-delivery interval.

Is Glycated Hemoglobin A1c Level Associated with Adverse Pregnancy Outcomes of Women Affected by Pre-Gestational Diabetes?

Background and Objectives: This observational study aims to determine the correlation between glycemic control with the HbA1c value and adverse obstetric outcome in women affected by pre-gestational diabetes. Materials and Methods: A retrospective analysis has been performed at the University Hospital of Udine. Only patients with a singleton pregnancy, pre-gestational diabetes, and known level of Hb A1c throughout pregnancy were included in the study. Results: According to the HbA1c level, at the beginning of pregnancy, 49 patients with HbA1c ≤ 7.0% were compared with 45 patients with HbA1c > 7.0%. Maternal age at diagnosis of the disease was significantly higher in the group with HbA1c ≤ 7% than in the group with HbA1c > 7%, 26.00 (18.00–32.00) vs. 20.00 (12.50–27.00). Women with HbA1c ≤ 7.0% reached, at term of pregnancy, significantly lower levels of HbA1c, 5.8% (5.7–6.0) vs. 6.7% (6.3–7.3). Daily insulin units were statistically different between the two groups at the end of pregnancy (47.92 (39.00–67.30) vs. 64.00 (48.00–82.00)). Proteinuria was significantly higher in the group with HbA1c > 7.0%, who delivered at earlier gestational age (37.57 (35.57–38.00) vs. 38.14 (38.00–38.43). Moreover, women with HbA1c > 7.0% had a significantly higher prevalence of an adverse composite outcome. Of note, in multivariate logistic regression analysis, pregnancy complications were significantly correlated to pre-pregnancy HbA1c > 7.0% (OR 2.95 CI.95 1.16–7.48, p < 0.05) independently of age, insulin treatment, and type of diabetes. Conclusions: Our data, obtained from a single-center cohort study, suggest that starting pregnancy with poor glycemic control might predict more complex management of diabetes in the following trimesters.

Atosiban Combined with Ritodrine for Late Threatened Abortion or Threatened Premature Labor Patients with No Response to Ritodrine: A Clinical Trial

Background

Premature labor is an important cause of infant death and long-term disability. This study aimed to explore the safety and effectiveness of combining the tocolytic agents atosiban and ritodrine to extend gestation.

Material/Methods

The study included 52 patients with late threatened abortion and threatened premature labor between 20^0/7 and 33^6/7 weeks’ gestation who were administrated continuous tocolytic agents for 48 h. Patients were divided into a research group receiving ritodrine combined with atosiban, owing to having no response to ritodrine alone (n=30), and a control group receiving ritodrine alone (n=22). The mean infusion rate and duration of tocolytic administration, gestation extension, pregnancy outcomes, and adverse effects were recorded. Routine blood tests, including C-reactive protein, and cultures for leukorrhea, candida, and mycoplasma were performed before and 1 week after treatment.

Results

Patients receiving ritodrine with atosiban had a mean gestation extension of 42.53±31.70 days. The extension of gestation of the research group was statistically shorter than that of the control group (P<0.05). The fetal loss rate, newborn birth weight, and Apgar score at 1 min were similar between the 2 groups (all, P>0.05). The research group had a lower incidence of palpitations than the control group (P<0.05).

Conclusions

For patients with late threatened abortion or threatened premature labor not controlled with ritodrine alone, ritodrine combined with atosiban extends gestation and improves pregnancy outcomes. For patients with abnormal uterine contractions, routine testing for reproductive tract infection should be performed. When infection is present, anti-infective therapy should be administered.

The effects of tocolysis on neonatal septic death in women with PPROM: a retrospective cohort study

PURPOSE

In women with preterm premature rupture of membranes (PPROM), particularly those with suspected chorioamnionitis, the benefit of tocolysis on neonatal outcome remains unclear. Our purpose was to evaluate the effect of tocolysis on neonatal septic death in women with PPROM with and without chorioamnionitis.

METHODS

A retrospective cohort study was used to address our study objective. We created a cohort consisting of all live births between 24 and 32 weeks' gestation that were registered in the Linked Birth and Infant Death data files (2009-2013) from the United States. Multivariate logistic regression was used to evaluate the effect of tocolysis on neonatal septic death at 7 and 28 days in births with and without chorioamnionitis.

RESULTS

Of the 46,968 births that met our inclusion criteria, tocolysis was administered to 6264 (13.3%). Tocolysis was more commonly prescribed to Caucasians, smokers, in multiple birth pregnancies, and to women with a history of preterm births. Tocolysis was not significantly associated with neonatal septic death at 7 days (OR 0.66, 95% CI 0.39-1.13) or at 28 days (OR 0.85, 95% CI 0.60-1.19). This was consistent in pregnancies with and without chorioamnionitis. Furthermore, tocolysis was associated with a reduced risk of neonatal septic death at 7 days when administered between 24 and 27 weeks' gestation (OR 0.44, 95% CI 0.22-0.88).

CONCLUSIONS

In the setting of PPROM, tocolysis does not appear to increase the risk of neonatal septic death at 7 and 28 days. Therefore, consideration should be given to its administration if clinically indicated.

Efficacy and side effect of ritodrine and magnesium sulfate in threatened preterm labor

Objective

In terms of efficacy, several previous studies have shown that the success rate in inhibiting preterm labor was not different between magnesium sulfate and ritodrine. However, there is a paucity of information regarding the efficacy of both medications after consideration of intra-amniotic infection, which is one of the most important prognostic factors in patients of threatened preterm birth. The objective of this study was to compare the efficacy and safety of magnesium sulfate with that of ritodrine in preterm labor.

Methods

In this retrospective cohort study, we included patients who were admitted and treated with either ritodrine or magnesium sulfate with the diagnosis of preterm labor at 24-33.6 weeks of gestational age between January 2005 to April 2015. Patients were divided into 2 groups according to the first-used tocolytics (ritodrine group and magnesium sulfate group). We compared the efficacy and prevalence of side effect in each group. The efficacy of both tocolytics was evaluated in terms of preterm delivery within 48 hours, 7 days, or 37 weeks of gestation and need for 2nd line therapy.

Results

A total number of 201 patients were enrolled including 177 cases in ritodrine group and 24 cases in magnesium sulfate group. The efficacy of both tocolytics (preterm delivery within 48 hours, 7 days, or 37 weeks of gestation and need for 2nd line therapy) was not different between the 2 groups of cases. In multivariate analysis, gestational age at treatment, twin gestation, intra-amniotic infection and maternal C-reactive protein (CRP) was associated with treatment failure (preterm delivery within 48 hours), but the type of tocolytics was not significantly associated with treatment failure. The type of side effect was different in the 2 groups, but the frequency of total adverse effect, need for discontinuation of therapy because of maternal adverse effect, and severe adverse effect were not different between the two groups of cases.

Conclusion

The efficacy and safety of magnesium sulfate was similar to ritodrine, and can be a substitute tocolytics. Additionally, failure of tocolytic therapy was determined by gestational age at treatment, twin gestation, intra-amniotic infection, and maternal CRP, not by the type of tocolytics.

Association between ß2-adrenergic receptor gene polymorphisms and adverse events of ritodrine in the treatment of preterm labor: a prospective observational study

Background

Ritodrine, a tocolytic β2-agonist, has been used extensively in Europe and Asia despite its safety concerns. This study was designed to identify associations between β2-adrenergic receptor (ADRB2) polymorphisms and adverse drug events (ADEs) in patients with preterm labor treated with ritodrine.

Results

This follow-up study was prospectively conducted at Ewha Womans University Mokdong Hospital in Korea. Five single nucleotide polymorphisms (SNPs) of the ADRB2 gene (rs1042713, rs1042714, rs1042717, rs1042718, and rs1042719) were analyzed in 186 pregnant women with preterm labor. Patients with the AA genotype of rs1042717 had significantly lower incidence of ADEs compared to those with the G allele (p = 0.009). In multivariate analysis, one of the predictors of ADEs was the maximum infusion rate of ritodrine (AOR 4.47, 95% CI 1.31–15.25). Rs1042719 was also a significant factor for ritodrine-induced ADEs. The CC genotype carriers had 78% decreased risk of ADEs compared to those with other genotypes.

Conclusions

This study demonstrates that ADEs induced by ritodrine are associated with ADRB2 gene polymorphisms, as well as the infusion rate of ritodrine in pregnant women with preterm labor.

Successful treatment with granulocyte-colony stimulating factor for ritodrine-induced neutropenia in a twin pregnancy

OBJECTIVE

Neutropenia developed after continuous intravenous infusion of ritodrine hydrochloride (Yutopar) for preterm uterine contractions in a twin pregnancy. We successfully returned the low neutrophil count to the normal range after discontinuation of infusion of ritodrine and treatment with granulocyte colony stimulating factor (G-CSF).

CASE REPORT

A 34-year-old woman with twin pregnancy was treated with ritodrine for preterm uterine contractions at 27 weeks and 6 days gestation. Neutropenia developed after continuous intravenous infusion of ritodrine for about 4 weeks. We ceased the ritodrine infusion immediately and treated the neutropenia with G-CSF. A cesarean delivery was performed the day after cessation of the ritodrine infusion because of uncontrolled preterm labor. There were no adverse side effects or infectious complications in the mother or the newborns. The maternal neutrophil count recovered to the normal range 4 days after administration of G-CSF.

CONCLUSION

Based on prior case reports and the clinical presentation of our case, G-CSF may be a useful treatment for pregnant women with ritodrine-induced neutropenia. However, more clinical studies are required to confirm the safety and efficacy of this treatment.

Sulfation of ritodrine by the human cytosolic sulfotransferases (SULTs): Effects of SULT1A3 genetic polymorphism

Previous studies have demonstrated the metabolism of ritodrine through sulfation. The current study was designed to identify the human SULTs that are capable of sulfating ritodrine and to investigate how genetic polymorphism of the major ritodrine-sulfating SULT, SULT1A3, may affect its sulfating activity. A systematic analysis revealed that of the 13 known human SULTs, SULT1A1, SULT1A3, and SULT1C4, were capable of mediating the sulfation of ritodrine, with SULT1A3 displaying the strongest sulfating activity. Effects of genetic polymorphism on the sulfating activity of SULT1A3 were examined. By employing site-directed mutagenesis, 4 SULT1A3 allozymes were generated, expressed, and purified. Purified SULT1A3 allozymes were shown to exhibit differential sulfating activity toward ritodrine. Kinetic studies further demonstrated differential substrate affinity and catalytic efficiency among the SULT1A3 allozymes. Collectively, these results provided useful information concerning the differential metabolism of ritodrine through sulfation in different individuals.