Efficacy of aggressive tocolysis for preterm labor with advanced cervical dilatation

Objective.?Study the effectiveness of tocolysis for preterm labor with advanced cervical dilatation (???3?cm) to achieve sufficient latency for the effect of steroids to occur, and delivery of more mature neonates.

Study design.?We studied 249 singleton pregnancies, 23–36 weeks gestation in preterm labor, stratified by weeks of gestation and degree of cervical dilatation (Group A: 117, <?3?cm; Group B: 132, ???3?cm) who were given tocolysis and compared for the length of latency and neonatal outcome.

Results.?Maternal characteristics were similar between groups except African-American women were admitted with more advanced cervical dilatation. Latency ??72?hours was achieved in Group A: >?75% at all gestational ages, and Group B: >?50%. Latency >?72?hours, according to the degree of cervical dilatation, was for Group A: 90%, for Group B: 50–75% from >?3–5?cm dilatation, and 40% at 5.1–6?cm dilatation. Neonatal morbidity was mild with a decreased risk of long-term disability.

Conclusions.?Aggressive tocolytic therapy for preterm labor with advanced cervical dilatation is efficacious, allows for steroid therapy, and allows delivery of more mature neonates.     

Maintenance tocolysis with oral micronized progesterone for prevention of preterm birth after arrested preterm labor

Objective

To evaluate the efficacy of maintenance therapy with oral micronized progesterone (OMP) for prolongation of pregnancy in cases of arrested preterm labor.

Methods

Ninety women at 24–34 weeks of singleton pregnancy with intact membranes and arrested preterm labor were randomly allocated to receive OMP (n = 45) or placebo (n = 45) daily until 37 weeks or delivery, whichever was earlier. Outcome parameters were compared using Student t test, χ² test, Fisher exact test, and log-rank χ² test.

Results

OMP significantly prolonged the latency period (33.29 ± 22.16 vs 23.07 ± 15.42 days; P = 0.013). Log-rank analysis revealed a significant difference in mean time to delivery between the 2 groups (P = 0.014). There were significantly fewer preterm births (33% vs 58%; P = 0.034) and low birth weight neonates (37% vs 64%; P = 0.017), and significantly higher mean birth weight (2.44 ± 0.58 vs 2.14 ± 0.47 kg; P = 0.009) in the OMP group. Perinatal outcomes and adverse effects were similar in the 2 groups.

Conclusion

Maintenance tocolysis with OMP significantly prolonged pregnancy and decreased the number of preterm births.Clinical Trial Registry of India: CTRI/2011/10/002043.     

Maintaining and repeating tocolysis: A reflection on evidence

It is inherent to human logic that both doctors and patients want to suppress uterine contractions when a woman presents in threatened preterm labor. Tocolysis is widely applied in women with threatened preterm labor with a variety of drugs. According to literature, tocolysis is indicated to enable transfer to a tertiary center as well as to ensure the administration of corticosteroids for fetal maturation. There is international discrepancy in the content and the implementation of guidelines on preterm labor. Tocolysis is often maintained or repeated. Nevertheless, the benefit of prolonging pregnancy has not yet been proven, and it is not impossible that prolongation of the pregnancy in a potential hostile environment could harm the fetus. Here we reflect on the use of tocolysis, focusing on maintenance and repeated tocolysis, and compare international guidelines and practices to available evidence. Finally, we propose strategies to improve the evaluation and use of tocolytics, with potential implications for future research.     

The effect of celecoxib for treatment of preterm labor on fetuses during the second trimester of pregnancy: A pilot case series

ObjectiveAlthough cyclooxygenase inhibitors effectively suppress uterine contraction, constriction of the fetal ductus arteriosus (DA) and oligohydramnios are major concerns. Celecoxib, a selective cyclooxygenase 2 inhibitor, is a potential potent tocolytic agent, but there are no studies that have evaluated the beneficial or adverse effects of celecoxib use on fetuses for more than 48 hours in pregnant women. We therefore aimed to evaluate the effect of middle-long-term celecoxib administration on the fetus during the second trimester of pregnancy, particularly in terms of fetal DA and amniotic fluid volume.Materials and methodsWe retrospectively extracted and reviewed data from patients with preterm labor who received celecoxib for tocolysis for more than 48 hours between 2016 and 2020. Celecoxib was used for tocolysis only when treatment of patients with conventional tocolytic agents was ineffective. Data on the peak systolic velocity in ductus arteriosus (PSV-DA) and the maximum vertical pocket (MVP) were collected.ResultsA total of 15 patients were eligible. The median gestational age at celecoxib introduction was 22.6 weeks, and the median period of administration was 9 days (range 3–40 days). The median gestational age at delivery was 27.1 weeks, and the median duration from initial celecoxib administration to delivery was 40 days. The Z scores of PSV-DA and MVP did not change significantly after celecoxib administration. During administration, PSV-DA exceeded the 95th percentile of the corresponding normal reference range in three cases, but the levels returned to normal after reduction or discontinuation of treatment. There was no oligohydramnios during the treatment.ConclusionCelecoxib administration for more than 48 hours in the second trimester of pregnancy might be safe and tolerable in terms of fetal PSV-DA and amniotic fluid volume as long as careful ultrasound monitoring is performed. Celecoxib could be an alternative for preterm labor when conventional tocolysis is not effective.     

Ultrasonic measurements of the cervix and preterm labor

During the past few years a clear relationship has been established between decreased cervical length and risk of spontaneous preterm delivery. In this review, the most recent publications are described, and results are compared with those of the present authors regarding the prevention of preterm labor in both asymptomatic and symptomatic patients. Cervical assessment with ultrasound is now widely accepted and a well standardized method which can be easily performed in both high- and low-risk patients as a screening test for preterm delivery. It is the authors' belief that, for an evaluation of the cervix, all that is required is a well trained operator and a few minutes.     

Comparison of the efficacy and adverse effects of nifedipine and indomethacin for the treatment of preterm labor

Objective

To compare the effectiveness and adverse effects of nifedipine versus indomethacin in the treatment of preterm labor.

Methods

In a randomized clinical trial, 79 women with labor pain at 26-33 weeks of gestation were treated with either oral nifedipine (n = 40) or rectal indomethacin (n = 39).

Results

Twenty-three (59%) women in the indomethacin group, and 10 (25%) in the nifedipine group did not respond to treatment (P = 0.002). None of the 16 and 30 women remaining in the indomethacin and nifedipine groups, respectively, delivered during the subsequent 48 hours. Of these remaining women, 1 (6.25%) in the indomethacin group and 4 (13.3%) in the nifedipine group delivered between 48 hours and 7 days (P = 0.162). For the women who responded to treatment, the mean gestational age at time of delivery was 238.5 ± 19.4 days and 246.4 ± 15.4 days in the nifedipine and indomethacin groups, respectively (P = 0.182). Seventeen (42.5%) women in the nifedipine group, and 11 (28.2%) in the indomethacin group showed adverse effects (P = 0.184).

Conclusion

Indomethacin was less effective than nifedipine for the fast treatment of preterm labor. For women who responded to treatment within 2 hours, however, the delaying of delivery by indomethacin was similar to that by nifedipine.     

Myometrial elasticity determined by elastosonography to predict preterm labor

Abstract

Aim: To determine the utility of elastosonography (ES) combined to cervical length measurement to predict preterm labor.

Methods: One hundred twenty-seven women with pregnancies between 21 to 36 weeks of gestation without any risk factor for preterm labor were included in the study. All subjects underwent sonographic evaluation including fetal biometry, cervical length measurement and ES of uterine myometrium. Subcutaneous tissue was the reference point for ES evaluation. Tissue strain ratio values were obtained from all patients.

Results: Cervical length was a significant predictor for preterm delivery (AUC?=?0.958, p?<?0.001). Optimal cut-off value was obtained at 30?mm with 92% sensitivity and 81% specificity. Elastosonographic strain ratio was also a significant predictor for preterm delivery (AUC?=?0.827, p?<?0.001). Optimal cut-off value was obtained at 4.7 with 79% sensitivity and 91% specificity. In linear regression analysis, strain ratio (R^2?=?0.61, beta?=?0.171, p?=?0.03) and cervical length (R^2?=?0.61, beta?=??0.516, p?<?0.001) were significantly associated with preterm delivery. Cervical length?<?30?mm [39.1 (95 CI, 6.6–231.5, p?<?0.001)] and strain ratio?>?4.7 [24.5 (95 CI, 4.1–146.5, p?<?0.001)] were the risk factors for preterm delivery.

Conclusion: Elastosonographic evaluation of uterine myometrium was found to be significantly correlated with cervical length but cervical length measurement is a better predictor for preterm labor than ES.     

Intravenous tocolysis with Bryophyllum pinnatum is better tolerated than beta-agonist application

OBJECTIVE: To compare tolerability and tocolytic outcome between i.v. infused plant extract, Bryophyllum pinnatum, and beta-agonists. STUDY DESIGN: In a retrospective study, 67 pairs of pregnant women in preterm labor treated with intravenous B. pinnatum or beta-agonists were closely matched for maternal age, gestational age at tocolysis, CTG recorded contractions, cervical effacement, preterm premature rupture of the membranes, and history of preterm labor. Endpoints were prolongation of pregnancy, gestational age at delivery, pre- and postpartum duration of hospitalization, maternal tolerability, neonatal outcome and morbidity. RESULTS: Pregnant women with B. pinnatum and beta-agonists were equal in the prolongation of pregnancy (6.2 versus 5.4 days, NS), the gestaional age at delivery (38.0 versus 37.1 weeks, NS) and the duration of hospitalisations, but had less adverse effects (34.3 versus 55.2% with palpitation or dyspnea, P=0.02). The neonatal outcome and morbidity in the B. pinnatum group were equal or better (oxygen use 10.4 versus 44.8%, P<0.001; respiratory distress syndrome 4.5 versus 19.4%, P=0.01). CONCLUSION: In the management of preterm labor B. pinnatum is no less effective than beta-agonists, but is significantly better tolerated.     

早产临床风险因素的探讨

目的评估影响早产分娩的风险因素以及对早产干预措施影响的相关因素。方法选择2003年1月至2006年3月发生在34周前的自发性早产临产、早产胎膜早破、宫颈机能不全、先兆早产4种临床表现类型共221例,比较4种临床表现之间发病的风险因素及影响干预措施结局的相关因素。结果自发性早产临产的风险因素依次为:本次妊娠先兆流产史(OR8.917,95%CI2.308～34.457)、胎次(OR2.179,95%CI1.033～4.598)、宫颈长度改变(OR0.366,95%CI0.259～0.518);早产胎膜早破的风险因素依次为:自然流产史(OR4.922,95%CI1.115～21.720)、体外受精-胚胎移植(IVF-ET)(OR5.341,95%CI1.571～18.164);宫颈功能不全的风险因素依次为:早产史(OR9.010,95%CI2.032～39.940),IVF-ET(OR2.603,95%CI1.195～5.670)。发生早期早产分娩的影响因素依次为:血象升高(OR4.695,95%CI2.065～10.671)、宫颈长度变短(OR0.633,95%CI0.456～0.880)。对早产干预措施的影响因素为紧急宫颈环扎术(OR26.372,95%CI2.770～251.085)和血象升高(OR7.111,95%CI1.769～28.53)。结论影响早产的风险因素较多,应注重IVF-ET妊娠的早产风险;实施紧急宫颈环扎术及注重感染指标监测是减少34周前分娩的重要干预手段。     

The effects of ritodrine and magnesium sulfate on maternal and fetal Doppler blood flow patterns in women with preterm labor

Objective

To determine the effects of ritodrine and magnesium sulfate on maternal-fetal blood flows.

Study design

A total of 85 pregnant women between 26th and 36th weeks with preterm labor, and 83 healthy pregnant women were included. Patients in the study group were randomly assigned to receive either ritodrine (with the addition of verapamil) (n = 46) or magnesium sulfate (n = 39). Blood flow examinations on the umbilical artery (UA), middle cerebral artery (MCA), bilateral uterine arteries (Ut.A) and ductus venosus (DV) were performed before and 48 h after initiating therapy.

Results

UA pulsatility index (PI) significantly differed in women receiving tocolysis compared to controls after 48 h. DV PI increased in women receiving MgSO₄, whereas it decreased in the ritodrine and control groups. Ut.A values did not significantly change after 48 h in the groups.In women between the 26th and 32nd weeks, UA, MCA and DV PI did not significantly change after 48 h in the three groups. However, in women between the 32nd and 36th weeks UA and MCA PI significantly differed in the treatment groups compared to controls after 48 h. DV PI increased in women receiving MgSO₄, whereas it decreased in the ritodrine and control groups.

Conclusions

MgSO₄ and ritodrine affect blood flow patterns after 48 h in some maternal-fetal vessels. These effects on blood flow are particularly significant in women between 32nd and 36th weeks. The effects of both drugs on fetal and maternal Doppler flows seem similar, except the increased resistance to flow in DV in women receiving MgSO₄.