A randomized controlled trial of cervical cerclage in women at high risk of spontaneous preterm delivery. A randomized trial of cerclage versus no cerclage among patients with ultrasonographically detected second-trimester preterm dilatation of the internal os. A randomized trial of cerclage vs. 17 alpha-hydroxyprogesterone caproate for treatment of short cervix. Final report of the Medical Research Council/Royal College of Obstetricians and Gynaecologists multicentre randomised trial of cervical cerclage. MRC/RCOG Working Party on Cervical Cerclage. Cervical cerclage for prevention of preterm delivery in women with short cervix: randomised controlled trial. A randomized controlled trial of cervical scanning vs history to determine cerclage in women at high risk of preterm birth (CIRCLE trial). Cerclage for prevention of preterm birth in women with a short cervix found on transvaginal ultrasound examination: a randomized trial. Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length. Final results of the Cervical Incompetence Prevention Randomized Cerclage Trial (CIPRACT): therapeutic cerclage with bed rest versus bed rest alone. Multicentred controlled trial of cervical cerclage in women at moderate risk of preterm delivery.
The effect of cervical suture on pregnancy outcome was studied in 194 women with a high risk (approximately 30%) of having a late abortion or a preterm delivery. The women were randomly allocated either to have a cervical suture inserted (n = 96) or to be managed without a suture (n = 98). There was no evidence that cervical cerclage either prolonged gestation or improved survival. Patients allocated to receive cerclage spent significantly longer in hospital, even when the period of admission for insertion was excluded. The patients in the cerclage group were more likely to receive tocolytic drugs, and more of them experienced puerperal pyrexia, although these differences between the groups were not statistically significant. The aim of this study was to compare perinatal outcomes of patients with second-trimester ultrasonographic evidence of preterm dilatation of the internal os treated with cerclage versus those of patients not treated with cerclage.
                From May 1998 through June 1999 patients with ultrasonographic evidence of preterm dilatation of the internal os between 16 and 24 weeks' gestation were randomly assigned to receive a McDonald cerclage or no cerclage. Before random assignment all patients underwent amniocentesis and urogenital cultures and then received 48 hours of therapy with indomethacin and antibiotics. After treatment each patient was followed up as an outpatient with bed rest and weekly ultrasonographic evaluation.
                Of the 61 patients 31 were randomly assigned to cerclage and 30 were randomly assigned to no cerclage. There were no differences between groups with respect to maternal demographic characteristics, risk factors for preterm birth, cervical measurements, rescue procedures, readmission, chorioamnionitis, and abruptio placentae. The mean gestational age at delivery (33.5 +/- 6.3 weeks) and the perinatal death rate (12. 9%) in the cerclage group were similar to the mean gestational age at delivery (34.7 +/- 4.7 weeks; P =.4) and the perinatal death rate (10.0%; P =.9) in the no-cerclage group.
                Treatment with McDonald cerclage of preterm dilatation of the cervix detected ultrasonographically during the second trimester did not improve perinatal outcomes. To determine pregnancy outcome in patients with short cervix on transvaginal ultrasound between 16 and 24 weeks' gestation treated with McDonald cerclage compared to weekly intramuscular injections of 17 alpha-hydroxyprogesterone caproate (17OHP-C).
                From November 2003 through December 2006, asymptomatic, singleton pregnancies were screened with transvaginal ultrasound between 16-24 weeks' gestation. Patients with a cervical length (CL) < or =25 mm were offered enrollment. Patients were randomly assigned to treatment with McDonald cerclage or weekly intramuscular injections of 17OHP-C. The primary outcome was spontaneous preterm birth (PTB) prior to 35 weeks' gestation.
                Seventy-nine patients met inclusion criteria; 42 were randomly assigned to the cerclage and 37 to 17OHP-C. Spontaneous PTB prior to 35 weeks' gestation occurred in 16/42 (38.1%) of the cerclage group and in 16/37 (43.2%) of the 17OHP-C group (relative risk, 1.14 95% CI, 0.67, 1.93). A post hoc analysis of patients with a prior PTB showed no difference in spontaneous PTB <35 weeks between groups. A similar analysis of patients with a CL< or =15 mm showed a reduction in spontaneous PTB <35 weeks in the cerclage group (relative risk 0.48, 0.24-0.97).
                Women with CL < or =25 mm in the second-trimester appear to have similar risks of delivering prior to 35 weeks' gestation when treated with 17OHP-C or McDonald cerclage. However, cerclage may be more effective in preventing spontaneous PTB in women with CL< or =15 mm. To assess whether cervical cerclage in women deemed to be at increased risk of cervical incompetence prolongs pregnancy and thereby improves fetal and neonatal outcome.
                Multicentre randomised controlled trial.
                Hospitals in the United Kingdom, France, Hungary, Norway, Italy, Belgium, Zimbabwe, South Africa, Iceland, Ireland, the Netherlands and Canada.
                One thousand two hundred and ninety-two pregnant women whose obstetricians were uncertain whether to recommend cervical cerclage, most of whom had a history of early delivery or cervical surgery.
                Cervical cerclage was compared with a policy of withholding the operation unless it was considered to be clearly indicated.
                Delivery before 33 completed weeks, preterm delivery (< 37 weeks), and vital status of the baby after completion of the pregnancy.
                The overall preterm delivery rate was 28%. There were fewer deliveries before 33 weeks in the cerclage group (83 (13%) compared with 110 (17%), P = 0.03) and this difference reflected deliveries characterised by features of cervical incompetence (painless cervical dilatation and prelabour rupture of the membranes). There was a corresponding difference in very low birthweight deliveries (63 (10%) compared with 86 (13%), P = 0.05). The difference in the overall rate of miscarriage, stillbirth or neonatal death (55 (9%) compared with 68 (11%)) was less marked and was not statistically significant. The use of cervical cerclage was associated with increased medical intervention and a doubling of the risk of puerperal pyrexia.
                These results suggest that the operation had an important beneficial effect in 1 in 25 cases in the trial (95% confidence interval (CI) 1 in 12 to 1 in 300 sutures). Its use is associated with increased medical intervention and puerperal pyrexia. Nevertheless, this trial suggests that, on balance, cervical cerclage should be offered to women at high risk, such as those with a history of three or more pregnancies ending before 37 weeks gestation. Cervical cerclage has been widely used in the past 50 years to prevent early preterm birth and its associated neonatal mortality and morbidity. Results of randomised trials have not generally lent support to this practice, but this absence of benefit may be due to suboptimum patient selection, which was essentially based on obstetric history. A more effective way of identifying the high-risk group for early preterm delivery might be by transvaginal sonographic measurement of cervical length. We undertook a multicentre randomised controlled trial to investigate whether, in women with a short cervix identified by routine transvaginal scanning at 22-24 weeks' gestation, the insertion of a Shirodkar suture reduces early preterm delivery.
                Cervical length was measured in 47?123 women. The cervix was 15 mm or less in 470, and 253 (54%) of these women participated in the study and were randomised to cervical cerclage (127) or to expectant management (126). Primary outcome was the frequency of delivery before 33 completed weeks (231 days) of pregnancy.
                The proportion of preterm delivery before 33 weeks was similar in both groups, 22% (28 of 127) in the cerclage group versus 26% (33 of 126) in the control group (relative risk=0.84, 95% CI 0.54-1.31, p=0.44), with no significant differences in perinatal or maternal morbidity or mortality.
                The insertion of a Shirodkar suture in women with a short cervix does not substantially reduce the risk of early preterm delivery. Routine sonographic measurement of cervical length at 22-24 weeks identifies a group at high risk of early preterm birth. We sought to compare history-indicated placement of cervical cerclage based on history- vs ultrasound-indicated placement in women at risk of preterm birth.
                We conducted a randomized controlled trial of history-indicated cervical cerclage suture based on history (clinician preference) vs ultrasound (< 20 mm cervical length) indicated in women at increased risk.
                The incidence of the primary outcome, preterm delivery between 24(+0) and 33(+6) weeks, was similar: 19/125 (15%) in the history-indicated group vs 18/122 (15%) in the ultrasound-indicated group (relative risk [RR], 0.97; 95% confidence interval [CI], 0.54-1.76). Those women randomized to the ultrasound-indicated arm were significantly more likely to receive a cerclage (32% vs 19%; RR, 1.66; 95% CI, 1.07-2.47) and progesterone (39% vs 25%; RR, 1.55; 95% CI, 1.06-2.25).
                Screening women at high risk with cervical ultrasound to determine cerclage placement results in more intervention but similar outcome compared with history-indicated placement. The purpose of this study was to determine the efficacy of cerclage and bed rest versus bed rest-only for the prevention of preterm birth in women with a short cervix found on transvaginal ultrasound examination.
                Women with > or =1 of high-risk factors for preterm birth (> or =1 preterm birth at < 35 weeks of gestation, > or =2 curettages, diethylstilbestrol exposure, cone biopsy, Mullerian anomaly, or twin gestation) were screened with transvaginal ultrasonography of the cervix every 2 weeks from 14 weeks of gestation to 23 weeks 6 days of gestation. Enrollment was offered to both asymptomatic women who were at high risk and who were identified to have short cervix (< 25 mm) or significant funneling (>25%) and nonscreened women who were at low risk and who were identified incidentally. The women who gave written consent were assigned randomly to receive either McDonald cerclage or bed rest-only. Both groups received similar counseling and treatment. Primary outcome was preterm birth at < 35 weeks of gestation.
                Sixty-one women were assigned randomly. Forty-seven pregnancies (77%) were high-risk singleton gestations. Thirty-one women (51%) were allocated to cerclage, and 30 women (49%) were allocated to bed rest. There were no differences between the groups in demographic characteristics, risk factors, and cervical variables. Preterm birth at < 35 weeks of gestation occurred in 14 women (45%) in the cerclage group and in 14 women (47%) in the bed rest group (relative risk, 0.94; 95% CI, 0.34-2.58). There was no difference in any obstetric or neonatal outcomes. A subanalysis of singleton pregnancies with previous preterm birth at < 35 weeks of gestation and a short cervix of < 25 mm (n = 31 women) also revealed no significant difference in recurrent preterm birth at < 35 weeks of gestation (40% vs 56%; relative risk, 0.52; 95% CI, 0.12-2.17).
                Cerclage did not prevent preterm birth in women with a short cervix. These results should be confirmed by larger trials. The objective of the study was to assess cerclage to prevent recurrent preterm birth in women with short cervix.
                Women with prior spontaneous preterm birth less than 34 weeks were screened for short cervix and randomly assigned to cerclage if cervical length was less than 25 mm.
                Of 1014 women screened, 302 were randomized; 42% of women not assigned and 32% of those assigned to cerclage delivered less than 35 weeks (P = .09). In planned analyses, birth less than 24 weeks (P = .03) and perinatal mortality (P = .046) were less frequent in the cerclage group. There was a significant interaction between cervical length and cerclage. Birth less than 35 weeks (P = .006) was reduced in the less than 15 mm stratum with a null effect in the 15-24 mm stratum.
                In women with a prior spontaneous preterm birth less than 34 weeks and cervical length less than 25 mm, cerclage reduced previable birth and perinatal mortality but did not prevent birth less than 35 weeks, unless cervical length was less than 15 mm. To compare preterm delivery rates (before 34 weeks of gestation) and neonatal morbidity and mortality in patients with risk factors or symptoms of cervical incompetence managed with therapeutic McDonald cerclage and bed rest versus bed rest alone.
                Cervical length was measured in patients with risk factors or symptoms of cervical incompetence. Risk factors for cervical incompetence included previous preterm delivery before 34 weeks of gestation that met clinical criteria for the diagnosis of cervical incompetence, previous preterm premature rupture of membranes before 32 weeks of gestation, history of cold knife conization, diethylstilbestrol exposure, and uterine anomaly. When a cervical length of <25 mm was measured before a gestational age of 27 weeks, a randomization for therapeutic cerclage and bed rest (cerclage group) or bed rest alone (bed rest group) was performed. The analysis is based on intention to treat.
                Of the 35 women who met the inclusion criteria, 19 were allocated randomly to the cerclage group and 16 to the bed rest group. Both groups were comparable for mean cervical length and mean gestational age at time of randomization, mean overall 20 mm and 21 weeks. Preterm delivery before 34 weeks was significantly more frequent in the bed rest group than in the cerclage group (7 of 16 vs none, respectively; P =.002). There was no statistically significant difference in neonatal survival between the groups (13 neonates survived in the bed rest group vs all in the cerclage group). The compound neonatal morbidity, defined as admission to the neonatal intensive care unit or neonatal death, was significantly higher in the bed rest group than in the cerclage group (8 of 16 vs 1 of 19, respectively; P =.005; RR = 9.5, 95% CI, 1.3-68.1).
                Therapeutic cerclage with bed rest reduces preterm delivery before 34 weeks of gestation and compound neonatal morbidity in women with risk factors and/or symptoms of cervical incompetence and a cervical length of <25 mm before 27 weeks of gestation. A total of 506 women at moderate risk of preterm delivery were randomly allocated to either cervical cerclage or a control group. Significantly more women in the group allocated to cerclage were admitted to hospital for reasons other than the operation and more received oral tocolytic drugs. There were also more caesarean sections and more preterm deliveries in the women allocated to cerclage although the differences between the two groups were small and not statistically significant.
Compared with no treatment, cervical cerclage reduces the incidence of preterm birth in women at risk of recurrent preterm birth without statistically significant reduction in perinatal mortality or neonatal morbidity and uncertain long-term impact on the baby. Ceasarean section is more likely in women who had cervical suture inserted during pregnancy.
The decision on how best to minimise the risk of recurrent preterm birth in women at risk, either because of poor history of a short or dilated cervix, should be 'personalised', based on the clinical circumstances, the skill and expertise of the clinical team and, most importantly, woman's informed choice.