Cervical pessary for preventing preterm birth: a meta-analysis.

OBJECTIVE: To evaluate the efficacy of cervical pessary in the prevention of preterm birth and its influence on pregnancy and maternal outcomes, so as to provide a clinical basis for cervical pessary to prevent premature delivery. METHODS: The databases of PubMed, Web of Science, CNKI, WanFang Data, etc, were used to search for the eligible articles. The relevant data were abstracted by two independent reviewers and performed with Stata 12.0. RESULTS: Pregnancy Result: the PTB rates of pessary and control group before 28, 32, 34, and 37 weeks were analyzed and the combined RR (95%CI) values were 0.78 (0.46, 1.31), 0.92 (0.67, 1.28), 0.74 (0.49, 1.13), and 0.79 (0.54, 1.15). Compared with the control group, the utilization rate of tocolytic and corticosteroids was decreased 21% (RR = 0.79, 95%CI = 0.66-0.94) and 18% (RR = 0.82, 95%CI = 0.70-0.96). The risk of PROM and the difference was not statistically significant (p > .05). Subgroup analysis showed that there was no significant difference on the PTB rate subgroup and twins subgroup during 28 and 34 weeks (p > .05). The results showed that there was no significant difference on neonatal weight <1500 g and <2500 g (p > .05). Three articles on the average gestational age were included in the cervical length <25 mm. The deepen analysis on the relationship between gestational weeks and neonatal showed that: the risk of neonatal sepsis was reduced by 55% (RR = 0.45, 95% = 0.22 - 0.93); RDS and intraventricular hemorrhage are no significant difference on pessary and control group. The neonatal results were analyzed by subgroup analysis of singletons and twins, and there was no significant difference between two groups (p > .05). CONCLUSIONS: Compared with expectant management, pessary could prolong pregnancy and reduce the rate of tocolysis and corticosteroids. More registered trials are ongoing which may substantially change our results.

In Pursuit of Progress Toward Effective Preterm Birth Reduction.

Recently the March of Dimes and the International Federation of Gynecology and Obstetrics Working Group on Preterm Birth released its findings from an extensive cross-country individual patient data analysis of 4.1 million singleton births in five high-income, very high human development index countries. The specific contributions of 21 risk factors for both spontaneous and health care provider-initiated preterm birth were assessed to better understand how these vary among the countries selected for intensive study. We also wished to evaluate whether currently used clinical interventions to prevent preterm birth are associated with lower rates of preterm delivery. Individual and population-attributable preterm birth risks were determined and an assessment made to identify any contribution to cross-country differences. With this massive data set it was possible to assess the ability to predict preterm birth given various sets of known risk factors. It was also possible to estimate the potential effects of successful interventions to reduce preterm birth in relation to advances in the research, health care policy, and clinical practice sectors. In this article we summarize the seven most important findings from these analyses. Clearly there is a paucity of explicit and currently identifiable factors that are amenable to intervention with current clinical practice or changes in public health policy. Thus, we see an urgent and critically important need for research efforts to elucidate the underlying biological causes of spontaneous preterm birth. The need for new innovative and effective interventions to successfully pursue progress toward effective preterm birth reduction has never been more apparent.

[How Reliable are Meta-Analyses? An Appraisal Using the Example of Magnesium Tocolysis]. / Wie verlässlich sind Metaanalysen? Eine Überprüfung am Beispiel der Magnesiumtokolyse.

INTRODUCTION: Crowther et al. 3 analysed the effectivity of magnesium tocolysis in preventing preterm birth. They conclude that there is no evidence for protection. In its latest guidelines, based on this Cochrane analysis, the German Association of Gynaecology and Obstetrics (DGGG) does not recommend any more the use of magnesium for tocolysis. Magnesium tocolysis is said neither to delay nor to prevent preterm birth. Moreover, magnesium could be responsible for increased mortality in infants. These conclusions are mostly based on the research of Mittendorf et al. 4. In a Cochrane study from 2014, which in principal was identical to the study mentioned above 3, Crowther et al. 6 confirm the previous findings and conclusions. METHOD: Having successfully applied magnesium tocolysis for many years, these surprising conclusions led us to review the soundness of the publications mentioned above. Combining the practical experience of many years with the results of a comprehensive literature retrieval, we finally contrasted this knowledge with the findings of the aforementioned publications that caused the DGGG to withdraw the recommendation for magnesium. RESULTS: To draw binding consequences from a meta-analysis is possible only when stringent quality guidelines are observed. The studies that were included in the Cochrane review of Crowther et al. 3 are very heterogeneous and are not suitable for concluding on poor or even lacking effectiveness of magnesium tocolysis. Furthermore, the cases of infant deaths, as stated by Mittendorf et al. 4, are very unlikely caused by magnesium. CONCLUSION: When including studies in a meta-analysis special attention has to be given to the relevance and unbiased selection of studies. To prevent any misjudgment, a thorough knowledge of the included studies seems essentiell. There is not sufficient evidence to withdraw the recommendation for applying magnesium tocolysis as a preventive measure to prevent preterm birth. In the sense of evidence-based medicine, long-standing, scientifically proven therapeutic success should be incorporated into the meta-analysis as well.

Cervical pessary to prevent preterm birth in women with twin gestation and sonographic short cervix: a multicenter randomized controlled trial (PECEP-Twins).

BACKGROUND: Spontaneous preterm birth (SPB) is the leading cause of perinatal morbidity and mortality. In twins, the rate of preterm birth is higher than in singletons; interventions to prevent preterm birth are needed in this high-risk population. OBJECTIVE: We sought to test whether a cervical pessary reduces the preterm birth rate in twin pregnancies with sonographic short cervix. STUDY DESIGN: A prospective, open-label, multicenter, randomized clinical trial was conducted in 5 hospitals in Spain. The ethics committees of all participating hospitals approved the protocol. The trial was registered as ClinicalTrials.gov, number NCT01242410. Eligible women were scanned in Spain. The primary outcome was SPB <34 weeks of gestation. Neonatal morbidity and mortality were also evaluated. RESULTS: Cervical length was measured in 2287 women; 137 pregnant women with a sonographic cervical length ≤25 mm (of 154 detected with a short cervix) were randomly assigned to receive a cervical pessary or expectant management (1:1 ratio). SPB <34 weeks of gestation was significantly less frequent in the pessary group than in the expectant management group (11/68 [16.2%] vs 26/66 [39.4%]; relative risk, 0.41; 95% confidence interval, 0.22-0.76). Pessary use was associated with a significant reduction in the rate of birthweight <2500 g (P = .01). No significant differences were observed in composite neonatal morbidity outcome (8/136 [5.9%] vs 12/130 [9.1%]; relative risk, 0.64; 95% confidence interval, 0.27-1.50) or neonatal mortality (none) between the groups. No serious adverse effects associated with the use of a cervical pessary were observed. CONCLUSION: The insertion of a cervical pessary was associated with a significant reduction in the SPB rate. We propose the use of a cervical pessary for preventing preterm birth in twin pregnancies of mothers with a short cervix.

Fetal fibronectin status and cervical length in women with threatened preterm labor and the effectiveness of maintenance tocolysis.

OBJECTIVE: To assess the effect of maintenance tocolysis in women who are at high or low risk for preterm delivery according to fetal fibronectin (fFN) status and cervical length (CL). STUDY DESIGN: We compared the risk of preterm delivery in fFN pos and fFN neg women and in women with a CL <15 mm and ≥15 mm, by using the Cox regression. Differences between the effectiveness of maintenance tocolysis in high- and low-risk women were assessed by using an interaction term. RESULTS: 122 fFN tests were taken, of which 50 were fFN pos. CL was measured in 236 women, of whom 52 women had a CL <15 mm. The median gestational age at delivery was lower in fFN pos women; fFN pos women had a higher hazard for preterm delivery at any point of time (HR 4.7; 95% CI 2.9 to 7.6). Comparable results were seen for CL. Neither fFN status nor CL did alter the effect of maintenance tocolysis, which was ineffective in the total randomized group, on the risk of preterm delivery (p for interaction = 0.87 for fFN and 0.18 for CL). CONCLUSION: Maintenance tocolytic therapy with nifedipine is ineffective and not dependent on fFN or CL status.

Tocolysis for Women With Early Spontaneous Preterm Labor and Advanced Cervical Dilation.

OBJECTIVE: To characterize tocolytic use and examine perinatal outcomes among women presenting very preterm with spontaneous labor and cervical dilation 4 cm or greater. METHODS: This was a retrospective cohort study. Data from January 2000 to June 2011 in a single health care system were reviewed. Women with singleton, nonanomalous fetuses and preterm labor with intact membranes between 23 and 32 weeks of gestation who had cervical dilation 4 cm or greater and less than 8 cm at admission were included. Women receiving one or more tocolytics (magnesium sulfate, indomethacin, or nifedipine) were compared with those who did not receive tocolysis. The primary outcome was composite major neonatal morbidity. RESULTS: Two hundred ninety-seven women were included; 233 (78.5%) received at least one tocolytic. Women receiving tocolysis were slightly less dilated (median 5 compared with 6 cm, P<.001) at presentation and were more likely to receive at least a partial course of corticosteroids (88.4% compared with 56.3%, P<.001). Initial composite severe neonatal morbidity rates were similar (41.6% compared with 43.8%, P=.761) regardless of tocolytic administration. Those receiving tocolysis were significantly more likely to be pregnant at least 48 hours after admission (23.6% compared with 7.8%, P=.005), but a similar proportion delivered within 7 days of admission (94.8% compared with 95.3%, P>.99), and delivery gestational ages were similar (28.9 compared with 29.2 weeks, P=.408). The incidence of chorioamnionitis and postpartum endometritis was similar between groups. CONCLUSION: The majority of women presenting very preterm with advanced cervical dilation received tocolysis. Although tocolysis administration increased the likelihood of achieving at least 48 hours of latency, initial neonatal outcomes were similar. LEVEL OF EVIDENCE: II.

Perinatal factors associated with active intensive treatment at the border of viability: a population-based study.

OBJECTIVE: The aim of this national population-based study was to identify perinatal and neonatal factors associated with active intensive treatment (AIT) of infants born at the periviable period of 22 to 24 weeks of gestation. STUDY DESIGN: Data from the Israel national very low-birth weight infant database on 2207 infants born alive in 1995 to 2010 at gestational age (GA) 22 to 24 weeks were evaluated. AIT was defined as endotracheal intubation in the delivery room or mechanical ventilation in the neonatal intensive care unit. Multivariable logistic regression analyses were used to identify the independent effect of demographic and perinatal factors on AIT for each gestational week. RESULT: Of the 2207 infants born at 22 to 24 weeks GA, 1643 (74.4%) received AIT and 564 (25.6%) received comfort care. AIT increased from 25.5% at 22 weeks to 62.7 and 93.5% at 23 and 24 weeks GA, respectively, reflecting a 4.66 (95% confidence interval (CI) 3.32 to 6.54)- and 29.8 (95% CI 19.9 to 44.6)-fold odds for AIT at 23 and 24 weeks GA, respectively, compared with 22-week GA infants. Perinatal treatments associated with AIT included maternal tocolytic therapy (odds ratio (OR) 1.51, 95% CI 1.04 to 2.20), prenatal steroid therapy, both partial (OR 3.30, 95% CI 2.14 to 5.10) and complete (OR 3.17, 95% CI 1.91 to 5.26) and cesarean delivery (OR 2.68, 95% CI 1.88 to 3.83). Each unit increase in birth weight z-score was associated with an OR of 1.58 (95% CI 1.30 to 1.92) for AIT. At 22 weeks GA, maternal tocolytic treatment was associated with higher odds of AIT. In the 23 and 24-week GA infants, maternal infertility treatment, antenatal steroids, cesarean delivery and higher-birth weight z-scores were significantly associated with AIT. Among 23-week GA infants, AIT decreased significantly in the period 2006 to 2010 compared with 1995 to 2000 (OR 0.51, 95% CI 0.34 to 0.77). CONCLUSION: An active approach in obstetric management of pregnancies appears to impact the neonatologists' decision to undertake AIT treatment in infants born at the border of viability. The higher odds for AIT associated with obstetric interventions might contribute to the reported beneficial effect of antenatal steroids and cesarean delivery on the survival of infants born at the border of viability.

[Use of calcium channel blockers (CCB) for tocolysis in France and abroad]. / Utilisation des inhibiteurs des canaux calciques (ICC) en tocolyse en France et à l'étranger.

OBJECTIVES: Calcium channel blockers (CCB) are routinely off-label used for tocolysis. The purpose of this study is to establish an inventory of the use of CCB for tocolysis in France and abroad. MATERIALS AND METHODS: Four complementary approaches were performed: (i) a literature review of clinical practice and guidelines of scientific societies; (ii) a national declarative practice survey among French tertiary care centers; (iii) a regional declarative practice survey among all maternities of the Midi-Pyrénées Perinatal Network (MATERMIP); (iv) an evaluation of outpatient tocolysis prescription, analyzing the departmental database EFEMERIS in order to examine drug prescribing during pregnancy. RESULTS: CCB appear to be currently used as first-line, initial tocolysis, in the majority of French maternity hospitals (82.5% of tertiary care centers). Oral Nifedipine is the predominant regimen (86%). CCB utilization rates appear higher than those reported in 2005 in the EVAPRIMA study. Beta-agonists appear rarely prescribed in 1st line (poor maternal tolerance) and even abandoned by many institutions (75% of tertiary care centers). Using a maintenance tocolysis (usually by long-acting CCB) seems to vary depending on the hospitals. It would be prescribed in more than 50% of cases (and probably more in type 1 or 2 hospitals), despite the lack of demonstrated benefit. Furthermore, we can estimate that about 1.5 to 2% of outpatient pregnant women receive a prescription of Nifedipine LP in France. CONCLUSION: CCB (especially Nifedipine) are widely used in the treatment of threatened preterm labor in France, regardless of the type of hospital. The terms of off-label prescribing are not met.

[Adverse effects of calcium channels blockers used as tocolytic treatment]. / Effets indésirables des inhibiteurs calciques utilisés dans le cadre de la tocolyse.

OBJECTIVE: Tocolysis with calcium channel blockers is widespread in France. However, these molecules are off label use for this indication. The objective of this work is to give an update on all the side effects of calcium channel blockers published or reported to the National Bank of Pharmacovigilance. MATERIALS AND METHODS: We conducted a literature review incorporating the animal experimental data on calcium channel blockers, retrospective and prospective studies (randomized or not) comparing different tocolytics, and the published clinical case reports. Finally we inquired the National Bank of Pharmacovigilance for reported cases of adverse effects after use of calcium channel blockers as tocolytics. RESULTS: Adverse effects are found in 2% to 6% of patients after use of nifedipine, of which 0.9% to 1.9% are severe. These are mainly headache, flushes and arterial hypotension. Data on Nicardipine are more limited. For the latter, adverse effects specifically related to the route of administration (induced phlebitis) are described but it seems that other adverse effects reported are not more frequent. Several meta-analyses have demonstrated a decrease in maternal side effects when using calcium channel blockers compared to ß-agonists. Comparison of calcium channel blockers to Atosiban is less documented. More rare serious side effects are reported as clinical cases, consisting almost exclusively of cardiovascular complications (dyspnea, pulmonary edema, myocardial infarction, arterial hypotension). They are more common with Nicardipine than Nifedipine. Similar observations are found by querying the National Bank of Pharmacovigilance. CONCLUSION: The prescription of calcium channel blockers as tocolysis exposes patients to maternal side effects, which are not serious most of the time, and less frequent than with the ß-agonist. Severe maternal complications were nonetheless reported more frequently with Nicardipine than Nifedipine, which justifies avoiding Nicardipine in tocolysis. Nifedipine is the most studied molecule. It is not possible to define a maximum posology from literature data. It seems unreasonable to associate different tocolytics and necessary to closely monitor maternal blood pressure, the occurrence of a skin reaction or hypersensitivity, dyspnea or chest pain during treatment.

Single versus combination tocolytic regimen in the prevention of preterm births in women: a prospective cohort study.

OBJECTIVE: Our objective is to compare the efficacy of combination regimen (salbutamol and nifedipine) against single regimen (nifedipine alone) in preventing preterm births among women with preterm labor. RESULTS: A total of 76 women with gestational age (GA) ranging from 24+0 to 35+6 weeks, who sought treatment for preterm labor with or without cervical dilatation, were recruited for the prospective cohort study. Of these, 38 (50%) had single tocolytic regimen and 38 (50%) had combination tocolytic regimen. The mean GAs at admission were similar for both groups at 31 weeks (±2.93) for Group 1 and 30.9 weeks (±2.88) for Group 2 (P=0.873). The mean GAs at delivery were 37.8 weeks (±1.98) for the single regimen and 36.2 weeks (±3.26) for the combined regimen (P=0.011). The mean tocolytic to delivery interval for the single regimen was longer at 6.74 weeks (±3.13) as compared with 5.21 weeks (±3.61) for the combination regimen (P<0.05). Those on the combination regimen complained of more adverse effects (P<0.001). CONCLUSION: Our study results suggested that the use of nifedipine as a single tocolytic regimen is as effective as the combination regimen in the delay of preterm births and has much less side effects. Hence, we recommend the sole use of nifedipine for the management of preterm labor.

Do nurses have worse pregnancy outcomes than non-nurses?

BACKGROUND: Nurses encounter multiple occupational exposures at work which may harm their reproductive health. The purpose of the study was to compare pregnancy complications and outcomes including cesarean deliveries, tocolysis, miscarriage, and preterm labor between female nurses and comparable women who were not nurses in Taiwan. METHODS: This nationwide population-based study was performed using the National Health Insurance Research Database from 1997 to 2008. We identified 3,656 pregnancies among 2,326 nurses and 111,889 pregnancies among 74,919 non-nurses. A generalized estimating equation was used to compare risks between the two groups. RESULTS: The rates of tocolysis (28.6 vs 22.3%), miscarriage (6.0 vs 5.3%), and preterm labor (8.1 vs 4.4%) were significantly higher among nurses than non-nurses. After adjustment for background differences, nurses had significantly higher risks for cesarean section (adjusted OR 1.12 [95% confidence interval (CI) 1.03-1.22]), tocolysis (OR 1.18 [95% CI 1.09-1.29]), and preterm labor (OR 1.46 [95% CI 1.28-1.67]) than non-nurses. CONCLUSIONS: Nurses are at higher risk for cesarean section, tocolysis, and preterm labor than non-nurses. Occupational exposure related to these adverse pregnancy outcomes should be examined. Strategies to decrease the risks should be developed to improve reproductive health among nurses.

Effect of induced abortions on early preterm births and adverse perinatal outcomes.

OBJECTIVES: To examine the association between prior induced abortions and prematurity and to explore potential mechanisms for a relationship, including second trimester pregnancy losses and infections. METHODS: We conducted a retrospective review of the records of all women who delivered between April 2001 and March 2006 using data from the McGill Obstetric and Neonatal Database. Exposure was categorized as having had no prior induced abortions, one prior induced abortion, or two or more prior induced abortions. Our primary outcome was gestational age at delivery, categorized as < 24 weeks, < 26 weeks, < 28 weeks, < 32 weeks and < 37 weeks. Secondary outcomes were intrapartum fever, NICU admission, and use of tocolysis. RESULTS: A total of 17 916 women were included in the study. Of these 2276 (13%) had undergone one prior induced abortion, and 862 (5%) had undergone two or more prior induced abortions. Women with a prior induced abortion were more likely to be smokers and to consume alcohol, and were less likely to be married. Women who reported one prior induced abortion were more likely to have premature births by 32, 28, and 26 weeks; adjusted odds ratios were 1.45 (95% CI 1.11 to 1.90), 1.71 (95% CI 1.21 to 2.42), and 2.17 (95% CI 1.41 to 3.35), respectively. This association was stronger for women with two or more previous induced abortions. Prior induced abortion was associated with an increased requirement for tocolysis in subsequent pregnancies, but there was no association between prior induced abortions and NICU admission, intrapartum fever, and preterm premature rupture of membranes. CONCLUSION: Our study showed a significant increase in the risk of preterm delivery in women with a history of previous induced abortion. This association was stronger with decreasing gestational age.

Effect of antenatal tocolysis on neonatal outcomes.

OBJECTIVE: Detail adverse neonatal effects in pregnancies treated with indomethacin (I), magnesium sulfate (M) or nifedipine (N). METHODS: Women in acute preterm labor with cervical dilatation 1-6 cm were randomized to receive one of three first-line tocolytic drugs. RESULTS: There were 317 neonates (I = 103, M = 95, N = 119) whose mothers were treated with tocolytic therapy. There was no difference in gestational age at randomization (average 28.6 weeks' gestation) or at delivery (31.6 weeks' gestation, p = 0.551), birth weight (p = 0.871) or ventilator days (p = 0.089) between the three groups. Neonatal morbidity was not different between the three groups; respiratory distress syndrome (p = 0.086), patent ductus arteriosus (p = 0.592), sepsis (p = 0.590), necrotizing enterocolitis (p = 0.770), intraventricular hemorrhage (p = 0.669) and periventricular leukomalacia (p = 0.124). CONCLUSIONS: There were no statistically significant differences between the three tocolytics as far as composite neonatal morbidity or mortality was concerned.

Assessing the quality of evidence for preterm labor tocolytic trials.

OBJECTIVE: To assess the quality of tocolysis randomized controlled trials (RCTs) and to determine trial factors contributing to better quality evidence. METHODS: The Cochrane Central Register of Controlled Trials, MEDLINE, MEDLINE In-Process, EMBASE and CINAHL were searched for terms "preterm labor," "tocolytic" or "obstetric labor, premature" up to 1 August 2009.Data regarding study design, characteristics, number of participants and outcomes reported were extracted by at least two review authors. Study quality was assigned using the Cochrane Collaboration Handbook methodology and categories. Trends for quality over time, the impact of study size and the individual drugs compared were analyzed for impact on overall quality of trials. RESULTS: Of the 3197 titles initially identified, 89 RCTs of tocolytic therapy were reviewed. Of the six quality areas, 10 (11.2%) trials satisfied all areas, while only one trial (1.1%) met one area. The mean number of adequate areas was 4.1 ± 1.2. Overall, 52 (58.4%) of the trials achieved high-quality categorization. Controlling for multiple trial factors, the trial continent and decade were significant predictors of overall trial quality. CONCLUSION: The majority of tocolysis RCTs are of high quality. Larger trials, more recent trials and placebo-controlled trials were associated with higher quality scores.

Factors associated with tocolytic hospitalizations in Taiwan: evidence from a population-based and longitudinal study from 1997 to 2004.

BACKGROUND: The use of tocolytic hospitalization in antenatal care is controversial and worthy of more research. We investigated individual, institutional, and area factors that affect the use of tocolytic hospitalizations in Taiwan where fertility has rapidly declined. METHODS: Longitudinal data from the 1996 to 2004 National Health Insurance Research Database in Taiwan were used to identify tocolytic hospitalizations. The probit model was used to estimate factors associated with tocolytic hospitalizations. RESULTS: The decline in fertility was significantly associated with the probability of tocolytic hospitalizations. Several physician and institutional factors-including physician's age, hospital ownership, accreditation status, bed size, and teaching status-were also significantly correlated to the dependent variables. CONCLUSIONS: The provision of inpatient tocolysis is influenced not only by clinical considerations but also by physician, institutional, and area factors unrelated to clinical need. Fertility declines in Taiwan may have led obstetricians/gynecologists to provide more tocolysis to make up for their lost income. If the explanation is further validated, reimbursement policies may need to be reviewed to correct for overuse of inpatient tocolysis. The correlation could also be explained by the increasing use of artificial reproductive technologies and higher social value of newborns. In addition, the physician and institutional variations observed in the study indicate potential misuse of inpatient tocolysis that warrant further investigation.

Tocolytic therapy: a meta-analysis and decision analysis.

OBJECTIVE: To determine the optimal first-line tocolytic agent for treatment of premature labor. METHODS: We performed a quantitative analysis of randomized controlled trials of tocolysis, extracting data on maternal and neonatal outcomes, and pooling rates for each outcome across trials by treatment. Outcomes were delay of delivery for 48 hours, 7 days, and until 37 weeks; adverse effects causing discontinuation of therapy; absence of respiratory distress syndrome; and neonatal survival. We used weighted proportions from a random-effects meta-analysis in a decision model to determine the optimal first-line tocolytic therapy. Sensitivity analysis was performed using the standard errors of the weighted proportions. RESULTS: Fifty-eight studies satisfied the inclusion criteria. A random-effects meta-analysis showed that all tocolytic agents were superior to placebo or control groups at delaying delivery both for at least 48 hours (53% for placebo compared with 75-93% for tocolytics) and 7 days (39% for placebo compared with 61-78% for tocolytics). No statistically significant differences were found for the other outcomes, including the neonatal outcomes of respiratory distress and neonatal survival. The decision model demonstrated that prostaglandin inhibitors provided the best combination of tolerance and delayed delivery. In a hypothetical cohort of 1,000 women receiving prostaglandin inhibitors, only 80 would deliver within 48 hours, compared with 182 for the next-best treatment. CONCLUSION: Although all current tocolytic agents were superior to no treatment at delaying delivery for both 48 hours and 7 days, prostaglandin inhibitors were superior to the other agents and may be considered the optimal first-line agent before 32 weeks of gestation to delay delivery.

Is long-term tocolysis effective for threatened premature labour?

There is some controversy regarding the optimum duration of tocolysis. This retrospective multicentre study was performed to evaluate whether long-term (> 2 days) tocolysis is effective in treating threatened premature labour. A total of 1147 eligible patients were grouped according to whether or not tocolytics were given, and according to route of administration and whether or not ritodrine (the standard tocolytic regimen in Japan) or other tocolytic was given. They were then further stratified into three subgroups, using the Baumgarten and Gruber tocolysis index (TI), to assess the efficacy of tocolysis treatment according to the risk of premature labour. Prolongation of gestation was significantly longer in patients treated with tocolytics for > 2 days compared with the unmedicated, bed-rest group. In women receiving tocolysis, the mean duration of prolonged gestation was 2.2 times longer in the intermediate-risk TI group and 3.1 times longer in the high-risk TI group compared with the unmedicated group. In the patients who received tocolysis, IV ritodrine was used in 86% of cases and was considered safe and effective for prolonging gestation in cases of threatened premature labour.

The association of elective cessation of tocolysis and preterm birth in singleton gestations.

We evaluated outcomes following tocolysis discontinuation in singleton pregnancies between 33.0 and 36.9 weeks' gestation. We performed a retrospective analysis of singleton pregnancies prescribed continuous subcutaneous terbutaline tocolysis. Patients without indicated preterm delivery discontinuing treatment between 33.0 and 36.9 weeks were evaluated ( N = 4253). Data were grouped by week at treatment discontinuation. Outcomes were compared for each week. Approximately 55% (2316/4253) delivered preterm (< 37 weeks). After treatment discontinuation, 58.1% (2472/4253) of patients delivered within 7 days and 41.2% (1752/4253) within 3 days. Median number of days from discontinuation to delivery was 5 (range, 0 to 65). Incidence of low birth weight (< or = 2500 g), neonatal intensive care unit admissions, days in nursery, and estimated charges decreased with each additional week of tocolysis (all P < 0.05, adjusted for multiple comparisons). Tocolysis discontinuation prior to term is associated with late-preterm birth, adverse neonatal outcomes, and increased estimated health care costs.

Contemporary practice patterns and beliefs regarding tocolysis among u.s. Maternal-fetal medicine specialists.

OBJECTIVE: To estimate maternal-fetal medicine specialists' practice patterns and perceived risks and benefits to tocolysis. METHODS: We performed a mail-based survey of all Society for Maternal-Fetal Medicine (SMFM) members in the United States. Subjects were asked whether they would recommend tocolysis and what would be their first-line tocolytic in five scenarios: 1) acute preterm labor; 2) maintenance tocolysis after arrested preterm labor; 3) repeat acute preterm labor; 4) preterm premature rupture of membranes (PROM) without contractions; and 5) preterm PROM with contractions. RESULTS: A total of 827 (46%) SMFM members responded. Ninety-six percent, 56%, 56%, 32%, and 29% would recommend tocolysis for acute preterm labor, repeat acute preterm labor, preterm PROM with contractions, preterm PROM without contractions, and maintenance tocolysis, respectively. The most common first-line tocolytic was magnesium for acute preterm labor (45%) and repeat acute preterm labor (41%); nifedipine was the most common maintenance tocolysis (79%). Eighty percent believed tocolysis was associated with moderate or significant benefit in the setting of acute preterm labor; however, fewer than 50% responded similarly for the other four scenarios. In all five scenarios, more than 50% of respondents indicated there was minimal or no risk associated with tocolysis. Having a nonacademic practice was independently associated with the recommendation for tocolysis. CONCLUSION: Almost all maternal-fetal medicine specialists recommend tocolysis in the setting of acute preterm labor, and many recommend tocolysis for other indications. Magnesium and nifedipine are the most commonly prescribed first-line tocolytics. LEVEL OF EVIDENCE: III.