A singleton pregnancy with placental chorioangioma and hydrops fetalis complicated with mirror syndrome and ritodrine-induced side effects: a case report

BACKGROUND

Ritodrine hydrochloride is a widely used beta-adrenergic agonist used to stop preterm labor in Taiwan. Many side effects causing maternal morbidity and mortality have been reported. We report a case complicated with ritodrine-induced side effects and mirror syndrome that was associated with placental chorioangioma.

CASE PRESENTATION

A 36-year-old singleton pregnant woman at 25 6/7 weeks of gestation, with an undiagnosed placental chorioangioma, underwent tocolysis due to preterm uterine contractions. Her clinical condition deteriorated, attributed to mirror syndrome and adverse events induced by ritodrine. An emergency cesarean section was performed at 27 1/7 weeks of gestation, delivering an infant with generalized subcutaneous edema. A placental tumor measuring 8.5 cm was discovered during the operation, and pathology confirmed chorioangioma. Gradual improvement in her symptoms and laboratory data was observed during the postpartum period. Identifying mirror syndrome and ritodrine-induced side effects poses challenges. Therefore, this case is educational and warrants discussion.

CONCLUSION

Our case demonstrates mirror syndrome induced by chorioangioma, which is rare, and ritodrine-induced side effects. The cessation of intravenous ritodrine and delivery are the best methods to treat maternal critical status due to fluid overload.

Neonatal hyperkalemia associated with maternal ritodrine: A retrospective study

BACKGROUND

We recently reported on a late preterm infant born at 36 weeks' gestation with serious arrhythmia due to hyperkalemia associated with long-term maternal ritodrine administration. It is unknown whether ritodrine alone increases the risk of neonatal hyperkalemia in infants born at 34-36 weeks' gestation.

METHODS

This single-center, retrospective, cohort study enrolled late preterm infants (34-36 gestational weeks) born between 2004 and 2018. Cases with maternal magnesium sulfate use were not sufficient for statistical analysis and so were excluded from the study. Risk factors for the occurrence of hyperkalemia were determined based on clinical relevance and previous reports.

RESULTS

In all, 212 late preterm infants with maternal ritodrine use and 400 infants without tocolysis were included in the study. Neonatal hyperkalemia occurred in 5.7% (12/212) in the ritodrine group and 1.8% (7/400) in the control group. The risk of neonatal hyperkalemia was significantly increased by maternal ritodrine administration with a crude odds ratio (OR) of 3.37 (95% confidence interval [CI]: 1.30-8.69; p < 0.01) and an adjusted OR of 3.71 (95% CI: 1.41-9.74; p < 0.01) on multivariable analysis. Long-term tocolysis (≥28 days) with ritodrine increased the risk of neonatal hyperkalemia with 9.3% (11/118) of infants developing hyperkalemia (adjusted OR 4.86; 95% CI: 1.59-14.83; p < 0.01). Neonatal hyperkalemia was not found within 2 weeks of ritodrine administration.

CONCLUSION

This research suggests that late preterm infants born after long-term ritodrine administration are at risk of neonatal hyperkalemia and require special attention.

Acute Pulmonary Edema Induced by a Low Dose of Ritodrine Hydrochloride: A Case Report

OBJECTIVE

Acute pulmonary edema associated with ritodrine hydrochloride is a rare, life-threatening complication, and dose and duration of ritodrine use are closely associated with this pathology. We report a case of acute pulmonary edema associated with short-duration infusion of ritodrine hydrochloride in a patient with pectus excavatum as an underlying factor.

CASE REPORT

A 30-year-old healthy pregnant woman was treated with oral ritodrine for tocolysis between 31 and 35 weeks of pregnancy. At 36 weeks of gestation, she went into preterm labor, with premature rupture of the membrane and breech presentation, and received an infusion of ritodrine hydrochloride for a few hours. Although she was normotensive until labor onset, mild hypertension and proteinuria were recognized. Intraoperatively, a funnel-chest deformity was observed, and she developed postoperative pulmonary edema associated with dyspnea and wet cough and confirmed on chest radiography and arterial gas analysis, and recovered with supportive care.

CONCLUSION

Small-dose infusion of ritodrine hydrochloride might cause pulmonary edema in patients with underlying medical problems, including pectus excavatum.

Synergic interaction between ritodrine and magnesium sulfate on the occurrence of critical neonatal hyperkalemia: A Japanese nationwide retrospective cohort study

Our aim was to evaluate the association between ritodrine and magnesium sulfate (MgSO4) and the occurrence of neonatal hyperkalemia or hypoglycemia among late preterm infants in a retrospective cohort study. We used a nationwide obstetrical database from 2014. A total of 4,622 live preterm infants born at 32-36 gestational weeks participated. Fourteen risk factors based on both clinical relevance and univariate analysis were adjusted in multivariable logistic regression analyses. Neonatal hyperkalemia and hypoglycemia occurred in 7.6% (284/3,732) and 32.4% (1,458/4,501), respectively. Occurrence of hyperkalemia was associated with concomitant usage of ritodrine and MgSO4 compared with no usage (adjusted odds ratio [aOR] 1.53, 95% confidence interval [CI] 1.09-2.15). Occurrence of hypoglycemia was associated with ritodrine alone (aOR 2.58 [CI 2.21-3.01]) and with concomitant usage of ritodrine and MgSO4 (aOR 2.59 [CI 2.13-3.15]), compared with no usage, and was associated with long-term usage (≥ 48 hours) of ritodrine and cessation directly before delivery. In conclusion, in late preterm infants, usage of ritodrine together with MgSO4 was associated with occurrence of critical neonatal hyperkalemia, and long-term usage of ritodrine and cessation directly before delivery were associated with neonatal hypoglycemia.

Association between total dose of ritodrine hydrochloride and pulmonary oedema in twin pregnancy: a retrospective cohort study in Japan

OBJECTIVE

Pulmonary oedema is recognised as a severe side effect of ritodrine hydrochloride. Recently, the number of twin pregnancies has been increasing. Few studies have reported the association between total dose of ritodrine hydrochloride prior to delivery and pulmonary oedema in twin pregnancy. We aimed to examine this association and determine the optimal cut-off threshold of total ritodrine hydrochloride dose to predict the incidence of pulmonary oedema in twin pregnancy based on obstetric records.

DESIGN

Retrospective cohort study.

SETTING

Yamanashi Prefectural Central Hospital, Japan.

PARTICIPANTS

Two hundred and twenty-six women with twin pregnancy who delivered at Yamanashi Prefectural Central Hospital between September 2009 and November 2016.

METHODS

The obstetric records of the participants were analysed. We defined 1 unit of ritodrine hydrochloride as 72 mg per 24 hours continuous transfusion at 50 µg/min to calculate the dose of ritodrine used for tocolysis.

OUTCOME MEASURES

Multivariable logistic regression analysis was performed to examine the association between total dose of ritodrine hydrochloride used for threatened preterm labour and pulmonary oedema, while controlling for potential confounding factors. Then, a receiver-operating characteristic curve was used to determine the optimal cut-off of total ritodrine dose to predict pulmonary oedema incidence.

RESULTS

Mean maternal age was 32 (range, 18-46) years; 143 participants were nulliparous (63.3%), 109 had (48.2%) term deliveries and 194 (85.8%) had caesarean deliveries. The overall incidence of pulmonary oedema was 13.7% (31/226). Multivariable analysis showed that the total dose of ritodrine was significantly associated with pulmonary oedema (adjusted OR 1.02; 95% CI 1.004 to 1.03). The best cut-off point to predict the incidence of pulmonary oedema was 26 units (1872 mg) (sensitivity, 61.3%; specificity, 87.8%).

CONCLUSION

Our results suggest that consideration of the total dose of ritodrine hydrochloride is helpful in the management of patients with threatened preterm labour in twin pregnancy.

The Association between Prenatal Yoga and the Administration of Ritodrine Hydrochloride during Pregnancy: An Adjunct Study of the Japan Environment and Children's Study

Introduction

While the beneficial effects of prenatal yoga have been reported in recent years, little is known about its effectiveness in pregnant Japanese women. Despite several adverse effects, ritodrine hydrochloride is frequently prescribed to suppress preterm labor in Japan, and its usage may therefore indicate cases of preterm labor. This study aimed to clarify the association between prenatal yoga and ritodrine hydrochloride use during pregnancy.

Methods

An observational study was conducted as an adjunct study by the Hokkaido unit of the Japan Environment and Children’s Study. Information on prenatal yoga practice was collected using a self-questionnaire between March 21, 2012, and July 7, 2015, targeting women who had recently delivered. Ritodrine hydrochloride use was identified from medical records. A total of 2,692 women were analyzed using logistic regression models that adjusted for possible confounders.

Results

There were 567 (21.1%) women who practiced prenatal yoga, which was associated with a lower risk of ritodrine hydrochloride use (adjusted odds ratio [OR] 0.77; 95% CI 0.61–0.98). This was especially evident in women with a total practice duration that exceeded 900 minutes throughout their pregnancy (adjusted OR 0.54; 95% CI 0.38–0.76). A sensitivity analysis that excluded patients with threatened abortion during the study period produced similar results.

Conclusions

Prenatal yoga was associated with a lower risk of ritodrine hydrochloride use, particularly in women with more than 900 minutes of practice time over the course of their pregnancy. Prenatal yoga may be a beneficial option for pregnant women in the selection of alternative therapies.

[A case of swelling of salivary gland due to drug treatment for threatened premature labor]

Ritodrine hydrochloride (luteonin), a beta-agonist with predominant effects on beta adrenoreceptors such as those of the uterus, is effective in suppressing premature uterine contractions. This medicine was used in drug treatment in the case of threatened premature labor. A 26-year-old female who complained of acute swelling of the bilateral salivary glands was consulted to our otorhinolaryngological department. The soft swelling of the bilateral parotid and submandibular glands had developed after intravenous administration of ritodrine hydrochloride for treatment of her threatened premature labor. In addition, serum amylase levels were elevated. The swelling of the salivary glands and the elevation of the serum amylase subsided following discontinuation of the ritodrine hydrochloride. In salivary glands, too, the beta-adrenoreceptors exist. Following stimulation of those receptors in those glands increased secretion of amylase occurs. Our findings suggested that beta-stimulation by ritodrine hydrochloride led to the swelling of the salivary glands and the elevation of the serum amylase. To our knowledge, in Japan, our case is the first otorhinolaryngological report of swelling of the salivary glands due to ritodrine hydrochloride. Otolaryngologist should therefore have full knowledge regarding swelling of salivary glands due to ritodrine hydrochloride.

[A suspected case of acute respiratory failure caused by ritodrine hydrochloride]

A 36-year-old woman was admitted to the obstetric department because of possible premature labor of twins at 35 weeks. She had been treated by ritodrine hydrochloride, a tocolytic agent, for 1 week, and delivered healthy twins by cesarean operation. After the operation, she suddenly complained of dyspnea with associated hypoxemia and was admitted to our hospital. She presented with hypoxemia and was given a diagnosis of pulmonary edema. She was given a diuretic with ventilator therapy, and improved rapidly. However, an echocardiogram showed continuing left ventricular systolic dysfunction after 3 months. From these results, this case was suspected to be pulmonary edema due to ritodrin after myocardial failure, including peripartum cardiomyopathy.

Ritodrine and isoxsuprine in management of preterm labor

INTRODUCTION

Preterm delivery is an important cause of perinatal morbidity and mortality. To decrease the medical and economical impact of preterm delivery, tocolytic agents are available among which isoxsuprine and ritodrine are widely used in Nepal. The study on efficacy of ritodrine and isosuprine has not been done yet in Nepelese women. So to observe on efficacy and safety of Ritodrine and Isoxsuprine, this study was conducted.

METHODS

A prospective observational study was conducted with an aim to assess the efficacy and safety of Isoxsuprine 10 mg orally eight hourly versus Ritodrine 10 mg initially infused intravenously along with 5% dextrose at the rate of 10 drops per minute with an increase of 5-10 drops every 30 minutes for 24 hours and then given oral at 5-10 mg eight hourly, in patient with preterm labor requiring uterine tocolysis.

RESULTS

This study found that Ritodrine is more effective and safer than Isoxsuprine in suppressing preterm labor. The failure rate of Isoxsuprine and Ritodrine were 22.22% and 6.5% respectively. The maternal side effects including cardiac side effects were significantly higher in Isoxsuprine. The cardiac side effects caused by Ritodrine can be controlled by adjusting the drip rate. Though Isoxsuprine seems more economical than Ritodrine, it is lesser cost effective to patients due to its higher failure rate, that results in added expenses in terms of increased morbidity and mortality.

CONCLUSIONS

Hence, Ritodrine is superior to Isoxsuprine as it is more efficacious in managing preterm labor and increasing fetal maturity. Also the adverse effects of Ritodrine are less than those of Isoxsuprine which result in better patient compliance and cost effectiveness.

[Acute coronary syndrome during a cesarean section in a healthy young woman]

Acute coronary syndrome (ACS) during pregnancy and delivery is a rare event that is usually related to prior disease or family history. Factors that contribute to the appearance of ACS during delivery in women with healthy coronary arteries include high doses of drugs to suppress contractions or increase uterine muscle tone and cardiovascular instability of any kind. Clinical and electrocardiographic abnormalities (eg, ST segment depression) that are suggestive of ACS have been reported to occur during cesarean section but without subsequent enzyme or echocardiographic abnormalities.

The effect of combined therapy with ritodrine, erythromycin and verapamil on the frequency of micronuclei in peripheral blood lymphocytes of pregnant women

The main aim of this study was to investigate the genotoxic effect of combined pharmacotherapy applied in post-operative treatment of cervical cerclage in pregnant women over six days. This study included 19 phenotypically healthy pregnant women in mid-trimester with a diagnosis of cervical insufficiency, mean age 28+/-5.33. The frequency of micronuclei (MN) was estimated in peripheral blood lymphocytes of patients before surgical intervention and after the end of applied pharmacotherapy by application of cytokinesis block micronucleus (CBMN) test. Mean value of baseline MN frequency was 6.84+/-2.91 MN/1000 binucleated cells, and after the end of the applied therapy, 10.32+/-4.27 MN/1000 binucleated cells (P<0.001) were found. The data of cell proliferation index showed that the combined therapy did not induce significant difference in cell kinetics (P>0.05). Our results showed that combined pharmacotherapy treatment over six days significantly increased the frequency of MN in peripheral blood lymphocytes of pregnant women.

Acute pulmonary edema secondary to long-term use of oral ritodrine in a woman with a triplet pregnancy

A 28-year-old primigravida who had taken oral ritodrine for 5 months to stop premature uterine contractions and was admitted in labor in the 33rd week of pregnancy developed acute pulmonary edema after cesarean section. Although parenteral ritodrine is the beta-adrenergic agent used most extensively to treat premature labor, only 1 case of pulmonary edema associated with long-term use of oral ritodrine had been reported so far. The present report presents for the first time computed tomographic findings of acute pulmonary edema secondary to tocolytic therapy.

[Acute myocardial infarction during tocolytic treatment with ritodrine]

Ritodrine, a beta2-adrenergic agonist with a selective effect on the uterine muscle, is prescribed to prevent premature labor and to treat a hypertonic uterus. At therapeutic doses ritodrine has chronotropic and peripheral vasodilator effects. At high doses it has been related to sporadic cases of subendocardial necrosis, pulmonary edema, and death in pregnancy. We report the case of a pregnant woman who had a non-Q wave acute myocardial infarction after administration of ritodrine.

Long-term follow up of children exposed in utero to nifedipine or ritodrine for the management of preterm labour

OBJECTIVE

To compare the long-term psychosocial and motor effects on children exposed in utero to nifedipine or ritodrine for the management of preterm labour.

DESIGN

Randomised controlled trial.

SETTING

Multicentre study in two university and one primary hospital in the Netherlands.

POPULATION

In the original trial, 185 women were randomised to either nifedipine (n = 95) or ritodrine (n = 90). Of the 185 liveborn children, 171 survived (92%), and of these 102 (61%) were followed up at age 9-12 years.

METHODS

Age-specific questionnaires were administered to the parent and teacher. Additional data were obtained from medical records.

MAIN OUTCOME MEASURES

Questionnaires were used to assess the child's behavioural-emotional problems, quality of life (QoL), motor functioning, parenting distress and the child's education.

RESULTS

Of the 171 eligible families, 102 (61%) agreed to participate and completed the questionnaires. Response was equal in the ritodrine group (n = 54 of 83 surviving children, 65%) compared with the nifedipine group (n= 48 of 88 surviving children, 55%). After controlling for differing perinatal characteristics at birth, no significant differences between the groups were detected with respect to long-term behaviour-emotional outcome, QoL, education, motor functioning or parenting distress. Psychosocial outcome was slightly better in the nifedipine group.

CONCLUSIONS

The results do not support any differential postnatal effect of the tocolytic agents ritodrine or nifedipine on the child's long-term psychosocial and motor functioning. The slightly better outcome of children randomised in the nifedipine group is most likely due to more favourable perinatal outcomes in this group. These results merit further investigation in a larger group of survivors.

Ritodrine in oral maintenance of tocolysis after active preterm labor: randomized controlled trial

AIM

To assess the efficacy of oral ritodrine in the form of sustained-release capsules for maintenance of uterine quiescence after successful treatment of threatened preterm labor.

METHODS

We randomized 120 women with singleton pregnancy who were successfully treated for threatened preterm labor before 34 completed weeks to receive either maintenance tocolysis with two 40 mg ritodrine sustained release capsules three times a day (study group, n=62) or no treatment (control group, n=58) for three days. The primary outcome measure was the recurrent episode of threatened preterm labor within 72 hours, which was defined as regular palpable uterine contractions and change in cervical effacement or cervical dilatation on clinical examination. Secondary outcome measures included the incidence of preterm birth, neonatal adverse outcomes, and maternal side effects.

RESULTS

There was no difference in the frequency of recurrent episodes of threatened preterm labor requiring another course of intravenous treatment between the study (8/62) and control (6/58) group of women (P=0.879). No differences were found between the study and control groups in any of the predefined secondary outcome measures, ie, delivery before 37 weeks (13/62 vs 7/58, respectively; P=0.288), delivery before 34 weeks (3/62 vs 1/58, respectively; P=0.682) and birth weight (3037-/+573 g vs 3223-/+423 g, respectively, P=0.862). There were more reported maternal side effects in the study group than in control group (47/62 vs 23/58, respectively; P(<0.001).

CONCLUSIONS

Additional maintenance ritodrine therapy was unnecessary in women with singleton pregnancy who had an episode of threatened preterm labor successfully treated with intravenous tocolytic therapy.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00290173.

Rhabdomyolysis Caused by Tocolysis with Oral Ritodrine Hydrochloride in a Pregnant Patient with Myotonic Dystrophy

Drug-induced rhabdomyolysis during pregnancy is extremely rare. We report here a rare case of ritodrine-hydrochloride-induced rhabdomyolysis in a pregnant patient with myotonic dystrophy. A 32-year-old primigravida was admitted because of premature labor at 31 weeks of gestation. She had been diagnosed as having myotonic dystrophy by electromyographic investigations and abnormal serum creatinine phosphokinase (CPK) levels. Tocolysis was initiated with oral ritodrine hydrochloride (15 mg/day) alone. There was a prompt response to the ritodrine hydrochloride. Three days after administration began, serum CPK levels had become markedly elevated to 10,897 mg/dl and myoglobinuria was detected (1,800 ng/dl), suggesting the presence of rhabdomyolysis. There was no evidence of worsening of the myotonic symptoms. Tocolysis was stopped immediately, and the laboratory data improved gradually. At 37 weeks of gestation, she spontaneously delivered a healthy male baby. Rhabdomyolysis has been recognized as a complication of tocolytic therapy with ritodrine hydrochloride. Therefore, beta-adrenergic agents should be used with great care, especially for patients with myotonic dystrophy, because of these agents' tendency to aggravate or precipitate myotonia and to induce rhabdomyolysis.

Effectiveness and safety of ritodrine hydrochloride for the treatment of preterm labour: a systematic review

PURPOSE

To analyse the available data on the effectiveness and safety of ritodrine hydrochloride in delaying delivery and in decreasing the incidence of preterm birth.

METHODS

Systematic review of randomised controlled trials (RCTs) that compared the effectiveness and safety of ritodrine hydrochloride with a placebo or with no treatment. Main outcome measures were relative risks (RRs) for perinatal mortality, neonatal respiratory distress syndrome (RDS), delivery within 48 hours or 7 days, preterm birth before 37 weeks gestation and low birth weight. We searched computerised databases (MEDLINE, CENTRAL, Ichushi Web) from their inception to October 2004, and searched the references of eligible trials.

RESULTS

Seventeen RCTs were included and meta-analysis was conducted. Pooled RRs relative to placebo for delivery within 48 hours or 7 days for parenteral ritodrine hydrochloride were 0.74 (95%CI (confidential interval): 0.56, 0.97), 0.85 (95%CI: 0.74, 0.97). There was no significant decrease in perinatal mortality, the proportion of RDS, preterm birth and low birth weight infants. Maternal side-effects significantly increased in patients receiving ritodrine with respect to those receiving a placebo. Pooled RRs relative to placebo for oral ritodrine hydrochloride showed no significant decrease in primary and secondary endpoints.

CONCLUSIONS

The effectiveness of parenteral ritodrine hydrochloride for tocolysis in preterm labour is limited to short-range prolongation of gestation. The effectiveness of maintenance tocolytic therapy with oral ritodrine hydrochloride was not proved.

Nifedipine versus ritodrine for suppression of preterm labor. Comparison of their efficacy and secondary effects

OBJECTIVES

To compare the efficacy of nifedipine and ritodrine in prolonging pregnancy beyond 48 h, 1 week and 36.0 weeks and to evaluate maternal side effects and adverse perinatal outcome.

STUDY DESIGN

Non-blinded, randomized controlled trial. Eighty patients with singleton pregnancies admitted for preterm labor with intact membranes between 22 and 35 weeks of gestation were included in the study. Preterm labor was defined as the persistence of at least two symptomatic uterine contractions within a 10 min period during 60 min after admission and despite bed rest.

RESULTS

Forty women received oral nifedipine and forty intravenous ritodrine. Two patients, one from each group, were excluded because of loss to follow-up after discharge. Therefore, 39 women in the nifedipine and the ritodrine groups, respectively, were evaluable for the final analysis. Baseline characteristics were comparable in both groups. The percentage of initial response, the speed of onset of action and the rate of successful treatment within 48 h were significantly better in the ritodrine group. However, prolongation of pregnancy beyond 7 days and 36 weeks of pregnancy was similar with a significantly lower rate of side effects in the nifedipine group.

CONCLUSIONS

In this small trial, ritodrine provided more effective tocolysis within the first 48 h than nifedipine at the doses used in this study, although with a significantly higher rate of side effects.

Severe hyperinsulinaemic hypoglycaemia in a baby born to a mother taking oral ritodrine therapy for preterm labour

Hyperinsulinism of infancy is a major cause of persistent hypoglycaemia in the newborn period. Transient mild self-limiting hyperinsulinaemia and hypoglycaemia have been described in neonates born to mothers taking ritodrine therapy for premature labour. Ritodrine crosses the placental barrier and enters the fetal circulation readily but the mechanism of how it causes hyperinsulinaemia and hypoglycaemia is unclear. We report the case of severe prolonged hyperinsulinaemic hypoglycamia in a neonate born to a mother taking ritodrine therapy from 16 weeks' gestation for preterm labour. The hyperinsulinaemic hypoglycaemia was managed with oral nifedipine as diazoxide was contraindicated due to fluid overload. Possible mechanisms of ritodrine-induced hypoglycaemia and insulin secretion are discussed.

Risk factors for cerebral palsy in preterm infants

OBJECTIVE

To identify crucial factors that precipitate cerebral palsy by controlling confounding factors in logistic regression analyses.

DESIGN AND PATIENTS

We retrospectively investigated a cohort of all 922 infants with gestational ages of less than 34 weeks (22-33 weeks), who were admitted to our neonatal intensive care unit between 1990 and 1998. Thirty (3.7%) were diagnosed to have cerebral palsy. We analyzed the prenatal and postnatal clinical variables of the cerebral palsy cases and compared them with 150 randomly selected controls.

RESULTS

Risk factors for cerebral palsy identified in univariate analysis were: twin pregnancy, long-term ritodrine tocolysis, respiratory distress syndrome, air leak, surfactant administration, intermittent mandatory ventilation, high frequency oscillation, lowest PaCO2 levels, prolonged hypocarbia during the first 72 h of life, and postnatal steroid therapy. In a conditional multiple logistic model, long-term ritodrine tocolysis, prolonged hypocarbia and postnatal steroid therapy remained associated with an increased risk of cerebral palsy after adjustment for other antenatal and postnatal variables (OR [Odds Ratio] = 8.62, 95% CI [Confidence Interval], 2.18-33.97; OR = 7.81, 95% CI, 1.42-42.92; OR = 21.37, 95% CI, 2.01-227.29, respectively).

CONCLUSIONS

Our results suggest that long-term ritodrine tocolysis underlines the development of cerebral palsy. Further assessments of the effect of ritodrine on fetal circulation and nervous system are required. Moreover, possible alternatives to systemic postnatal steroids are needed, and carbon dioxide levels should be more strictly controlled.

Ritodrine-induced leukocytoclastic vasculitis in pregnancy

OBJECTIVE

To report 2 cases of pregnant women who presented with leukocytoclastic vasculitis (LV) associated with the administration of ritodrine hydrochloride after undergoing genetic amniocentesis and to review the literature on LV. case summaries: Case 1. A 40-year-old pregnant woman was diagnosed with autoimmune hypothyroidism at week 12 of her third gestation. At week 14, she underwent a genetic amniocentesis and received oral prophylactic treatment with ritodrine for 10 days. At week 16, she presented with fever, epigastric abdominal pain, polyarthritis, microhematuria, and purpura. Skin biopsy showed LV. Case 2. A 34-year-old pregnant woman had developed polyarthralgias and polyarthritis after receiving ritodrine following genetic amniocentesis in her second gestation. She also underwent a genetic amniocentesis in her third gestation and received ritodrine. Five days later, she presented with fever, polyarthritis, and purpura. A skin biopsy demonstrated LV. The rest of her gestation was normal until week 33, when she developed oligohydramnios and a delay of intrauterine fetal growth. A cesarean section was then performed. After birth, the baby developed tachypnea, anemia, splenomegaly, edema, and renal failure; she died on her 15th day of life.

DISCUSSION

Ritodrine hydrochloride is a beta(2)-adrenergic agonist that is used in pregnant women as a tocolytic agent. In our 2 patients, there was a time relationship between the administration of ritodrine and the appearance of LV. In both cases, other causes of vasculitis were excluded in a reasonable way. As of November 4, 2003, only one other case has been found in the literature. An objective causality assessment revealed that the reactions to ritodrine were probable and possible, respectively, in our 2 cases.

CONCLUSIONS

In pregnant women with autoimmune disease, ritodrine should be used with caution because of its ability to induce vasculitis.

Pulmonary edema after ritodrine therapy during pregnancy and subsequent cesarean section with epidural anesthesia

Ritodrine, a beta-sympathicomimetic drug that is frequently used for the prevention of preterm birth. Preterm delivery is an important cause of low birth weight. One of the most important side-effects of ritodrine is pulmonary edema. In patients developing pulmonary edema after ritodrine therapy, aggressive fluid resuscitation during the operation period should be avoided. Successful epidural anesthesia can be achieved with a slow-onset epidural block after moderate fluid infusion. We report the management of a pregnant patient developing pulmonary edema after ritodrine therapy and undergoing cesarean section with epidural anesthesia.

Evaluation of creatine kinase level during long-term tocolysis

OBJECTIVE

This study was performed to evaluate serum creatine kinase (CK) levels during tocolytic therapy.

METHODS

A retrospective study was performed in 27 patients who were treated with intravenous tocolytic agents for more than one week. The first-line tocolytic agent was ritodrine hydrochloride, followed by concomitant magnesium sulfate (MgSO4). The serum CK level was measured on admission and every week thereafter. The patients were divided into the normal CK (group 1) and abnormal CK (> 150 IU/L) (group 2) groups.

RESULTS

Seventeen patients received both ritodrine hydrochloride and MgSO4. The CK levels in all patients rose significantly from 58.4 +/- 30.8 IU/L on admission to 116.0 +/- 68.7 IU/L on day 7 (p = 0.002). Abnormal elevation of CK occurred in 7 (25.9%) of the 27 patients. Significant differences were found between groups 1 and 2 in the total doses of ritodrine and MgSO4 (p = 0.046 and p = 0.0028, respectively). All patients in group 2 received ritodrine in combination with MgSO4 (p = 0.018).

CONCLUSION

When tocolytic therapy continued for more than 1 week, nearly one-fourth of patients showed an increase in CK level above the normal range.

Rhabdomyolysis during prolonged intravenous tocolytic therapy

A patient with twin gestation was hospitalized because of preterm labor and treated with intravenous ritodrine hydrochloride and magnesium sulfate. After more than 5 weeks of therapy, the patient developed muscle pain, which was diagnosed as rhabdomyolysis.

[A case of cardiac arrest at induction of anesthesia for postpartum hysterectomy]

Although peripartum cardiac arrest is rare, the prognosis of the event may be worse than in nonpregnant patients because the events is often associated with pulmonary or amniotic embolisms. The following report is a case of cardiac arrest which occurred at the induction of anesthesia for the postpartum hysterectomy. A 31-year-old woman was treated with infusion of ritodrine chloride for preterm labor and placenta previa. Elective cesarean section was performed at 37 weeks' gestation for her delivery under epidural anesthesia. Following the operation, the total hysterectomy was scheduled due to the continuous massive bleeding. She rapidly developed ventricular tachycardia, following trachea intubation with propofol and suxamethonium. Since she was not resuscitated with cardiac massage, we started intravenous epinephrine, electronic cardioversion, the percutaneous cardiopulmonary support and intra-aortic balloon pumping with epinephrine and dopamine infusions leading to a successfully outcome. In this case, we believe that the combination of propofol and suxamethonium had the most impact on producing the cardiac arrest. Therefore, the case emphasizes the potential danger of using these combination for patients who have been treated with ritodrine.

[Which tocolytic drugs in case of preterm labor?]

Because criteria used for the prediction of preterm labor are poorly effective, many patients receive tocolytic therapy in excess during pregnancy. Beta-mimetic agonists are the reference tocolytic drugs in most countries. Their efficacy in prolonging pregnancy compared to a placebo is proven although no benefit in neonatal morbidity or mortality has been demonstrated. Beta-mimetics have many contraindications, and side-effects are frequent. Serious complications such as pulmonary edema and maternal deaths, though rare, have been reported. Recent research has focused on tocolytic drugs with similar efficacy to beta-mimetics but with less side effects. Calcium-channel-blockers and oxytocin antagonists have been compared with beta-agonists in randomized trials. Both have demonstrated similar efficacy in the prolongation of pregnancy for at least 48 hours. Contrary to beta-mimetics, very few interruptions of treatment have been observed with these treatments. Other tocolytic drugs such as cyclooxygenase inhibitors, although effective in prolonging pregnancy, have unacceptable fetal side effects. Progesterone, antispasmodic drugs and magnesium sulfate have been widely used but their efficacy has not been demonstrated. More recent treatments such as NO-donors and cyclooxygenase-II specific antagonists are not sufficiently evaluated. In conclusion, three main classes may be used as first line tocolytic therapy, beta-adrenergic agonists, calcium-channel-blockers, and oxytocin antagonists. The choice among these treatments may be based on contraindications to beta-mimetics, side-effects of the treatment, or even economic reasons.

[Successful resuscitation of a patient with prolonged tocolytic therapy and an emergency cesarean section]

Ritodrine is the only medicament approved by FDA in the USA as well as in our country for prevention of the threatening preterm labor. Its adverse effects upon the respiratory and cardiovascular systems, including pulmonary oedema and myocardial ischemia, occur more frequently during the intravenous therapy than during the oral maintenance therapy. The aim of this report was to present a patient with cardiovascular adverse effects of ritodrine, who had her pregnancy terminated by an urgent cesarean section under general anesthesia. In the course of operation, the patient had two cardiac arrest (total of 70 min). Resuscitation was performed by direct and indirect heart massage. The patient's condition was stabilized during the next six hours. The patient was transferred to the coronary unit, where the treatment was continued for 30-days period, after which the patient was released home as completely recovered.

Intrauterine left chamber myocardial infarction of the heart and hydrops fetalis in the recipient fetus due to twin-to-twin transfusion syndrome

A rare complication of twin-to-twin transfusion syndrome (TTTS) is described: myocardial infarction of the recipient fetus. Myocardial infarction and hydrops are considered to be consequences of hypertension in the recipient. No other organs were affected. Pathological signs of intrauterine hypertension were estimated by the thickness of vessel walls and signs of hypertrophied myocardial cells. In the heart of the recipient fetus there was a chronic myocardial infarction near the apex cordis on the anterior wall with an aneurysm 4x5 mm in diameter. Diagnosis was based on light microscopic examination. The poor myocardial systolic function resulted in hydrops. Since the mother was administered beta sympathomimetics in therapeutic doses the contribution of the drug to the myocardial infarction is uncertain, but we would like to suggest this as a possible adverse effect in TTTS. The present case is the first reported myocardial infarction in connection with the syndrome.

Acute coronary syndrome associated with oral administration of ritodrine hydrochloride during pregnancy: a case report

We report a case of acute coronary syndrome associated with the oral administration of ritodrine hydrochloride. Ten days following the administration of ritodrine hydrochloride, the patient complained of chest pain, and an electrocardiogram showed ST elevation and ST depression. Intensive care was initiated. She recovered without chest pain.

Invasive pulmonary aspergillosis in a puerperant with drug-induced agranulocytosis

Invasive pulmonary aspergillosis (IPA) is an acute infection of Aspergillus species to the lungs. It generally occurs in immunocompromised hosts, especially with neutropenia. We report a 30-year-old puerperant, who developed IPA from agranulocytosis. She had been treated for threatened labor with ritodrine and cefepime, one of which induced agranulocytosis. After vaginal delivery of twins, pneumonia emerged in the right lower lobe. She was diagnosed to have IPA according to the halo sign on computed tomography (CT) and positive circulating antibody against Aspergillus, and was treated successfully with oral itraconazole followed by surgical resection. It is important to note that IPA might arise in otherwise immunocompetent hosts when neutropenia is long-standing.

Fetal heart rate patterns in normal and ritodrine-treated pregnancies, detected by magnetocardiography

OBJECTIVE

The aim of the present study was to test the validity of magnetocardiography in the diagnosis of fetal heart rate arrhythmias in normal pregnancies, as compared to the number of arrhythmias reported in other series, which were detected by use of other diagnostic techniques. We also evaluated the influence of ritodrine on the fetal heart rhythm in pregnancies treated for the risk of preterm labor by means of magnetocardiography, in order to provide preliminary results that could be utilized in the future establishment of magnetocardiography as a screening procedure in the diagnosis and management of fetal arrhythmias.

METHODS

We performed a prospective study on two subgroups of pregnant women: one of 84 women with normal healthy singleton pregnancies and one of 68 pregnant women treated with ritodrine for the risk of preterm labor.

RESULTS

The prevalence of fetal arrhythmias in the first subgroup was 3.5% (3/84), while in the second subgroup the prevalence was 16% (11/68).

CONCLUSIONS

The incidence of fetal arrhythmias detected in our population of normal pregnancies was comparable to that reported in previous studies by use of other techniques. Results gained from the second subgroup, although not comparable to others, owing to lack of similar reports, led us to believe that magnetocardiography's advantages over conventional methods of fetal cardiac surveillance could highlight the technique as a useful screening procedure for the detection of preterm fetuses, which should be submitted to closer investigation, because of the arrhythmias caused by ritodrine infusion.

Rebound perioperative hyperkalemia in six patients after cessation of ritodrine for premature labor

IMPLICATIONS

This report describes six patients who had marked hyperkalemia 60-150 min after cessation of intravenous ritodrine, which had been administered for management of preterm labor. Abnormal electrocardiographic findings are very important clues for a prompt diagnosis of hyperkalemia.

Effect of maternal tocolysis on the incidence of severe periventricular/intraventricular haemorrhage in very low birthweight infants

AIM

To examine the relation between grade III-IV periventricular/intraventricular haemorrhage (PVH/IVH) and antenatal exposure to tocolytic treatment in very low birthweight (VLBW) premature infants.

STUDY DESIGN

The study population consisted of 2794 infants from the Israel National VLBW Infant Database, of gestational age 24-32 weeks, who had a cranial ultrasound examination during the first 28 days of life. Infants of mothers with pregnancy induced hypertension or those exposed to more than one tocolytic drug were excluded. Of the 2794 infants, 2013 (72%) had not been exposed to tocolysis and 781 (28%) had been exposed to a single tocolytic agent. To evaluate the effect of tocolysis and confounding variables on grade III-IV PVH/IVH, the chi(2) test, univariate analysis, and a logistic regression model were used.

RESULTS

Of the 781 infants (28%) exposed to tocolysis, 341 (12.2%) were exposed to magnesium sulphate, 263 (9.4%) to ritodrine, and 177 (6.3%) to indomethacin. The overall incidence of grade III-IV PVH/IVH was 13.4%. In the multivariate logistic regression analysis, the following factors were related significantly and independently to grade III-IV PVH/IVH: no prenatal steroid treatment, low gestational age, one minute Apgar score 0-3, respiratory distress syndrome, patent ductus arteriosus, mechanical ventilation, and pneumothorax. Infants exposed to ritodrine tocolysis (but not to the other tocolytic drugs) were at significantly lower risk of grade III-IV PVH/IVH after adjustment for other variables (odds ratio = 0.3; 95% confidence interval 0.2 to 0.6).

CONCLUSION

This study suggests that antenatal exposure of VLBW infants to ritodrine tocolysis, in contrast with tocolysis induced by magnesium sulphate or indomethacin, was associated with a lower incidence of grade III-IV PVH/IVH.

Prolonged fetal ritodrine exposure and immediate neonatal outcome

Ritodrine hydrochloride was administered over a period of two years to a total of 200 women in premature labor. One hundred sixty-two (81 per cent) of the women carried pregnancy to 35 weeks or longer. To determine the effect of ritodrine on the neonates, the duration and amount of exposure, onset of exposure, and interval between cessation of exposure and delivery were correlated with gestational age, birth weight, Apgar scores, mortality, and the presence of hypoglycemia, hyperbilirubinemia, respiratory distress, and intrauterine growth retardation. Infants exposed for six weeks or more (long-term exposure) were significantly heavier than those exposed for shorter periods (short-term exposure), a difference that was possibly attributable to differences in gestational age at birth. Infants who were exposed as fetuses to ritodrine beginning at 30 weeks' or less gestation needed phototherapy more often than did infants whose fetal exposure began at after 30 weeks' gestation. Neither duration of exposure nor gestational age at birth was a significant factor in hyperbilirubinemia. Of infants delivered at or after 35 weeks' gestation, 32 (20 per cent) experienced early hypoglycemia; and 26 of these (81 per cent) were exposed up to the day of delivery. This outcome differed significantly from that of infants whose exposure stopped at least one week before delivery. In addition, respiratory distress syndrome was more common in those infants exposed up until delivery (34 of 36).(ABSTRACT TRUNCATED AT 250 WORDS)

Worldwide Atosiban versus Beta-agonists Study Group. Effectiveness and safety of the oxytocin antagonist atosiban versus beta-adrenergic agonists in the treatment of preterm labour. The Worldwide Atosiban versus Beta-agonists Study Group

OBJECTIVE

To compare the effectiveness and safety of the oxytocin antagonist atosiban with conventional beta-adrenergic agonist (beta-agonist) therapy in the treatment of preterm labour.

DESIGN

Three multinational, multicentre, double-blind, randomised, controlled trials. Setting Hospitals in Australia, Canada, Czech Republic, Denmark, France, Israel, Sweden, and the UK.

POPULATION

Women diagnosed with preterm labour at 23-33 completed weeks of gestation.

METHODS

Seven hundred and forty-two women were randomised; 733 received atosiban (n = 363; intravenous (iv) bolus dose of 6.75 mg, then 300 microg/minute iv. for 3h and 100 microg/min iv thereafter) or beta-agonist (n = 379; ritodrine, salbutamol or terbutaline iv; dose titrated) for at least 18h and up to 48 hours. Uterine contraction rate, cervical dilatation and effacement were used to assess progression of labour. An all patients treated analysis, using the Cochran-Mantel-Haenszel test, was performed.

MAIN OUTCOME MEASURES

Tocolytic effectiveness was assessed in terms of the number of women undelivered after 48 hours and seven days. Safety was assessed in terms of maternal side effects and neonatal morbidity.

RESULTS

There were no significant differences between atosiban and beta-agonists in delaying delivery for 48h (88.1% vs 88.9%; P = 0.99) or seven days (79.7% versus 77.6%; P = 0.28). Tocolytic effectiveness was also similar in terms of mean [SD] gestational age at delivery (35.8 [3.9] weeks vs 35.5 [4.1] weeks) and mean [SD] birthweight (2,491 [813] g versus 2,461 [831] g). Maternal side effects, particularly cardiovascular adverse events (8.3% vs 81.2%, P < 0.001), were reported more frequently in women given beta-agonists, resulting in more treatment discontinuations due to side effects (1.1% vs 15.4%, P = 0.0001). No statistical differences in neonatal/infant outcomes were observed with either study medication.

CONCLUSIONS

In the largest study of tocolytic therapy to date, atosiban was comparable in clinical effectiveness to conventional beta-agonist therapy, but was associated with fewer maternal cardiovascular side effects. We conclude that atosiban has clinical advantages over current tocolytic therapy.