To determine changes in length of incompetent cervices after cerclage, using transvaginal ultrasound.
Methods
Patients were enrolled in a prospective, observational study under an Institutional Review Board-approved protocol. McDonald or Shirodkar sutures were placed according to physician preference. Pre- and postcerclage cervical lengths were measured within 72 hours of the procedure. At each examination, the first measurement was discarded, and a mean of the subsequent three measurements was calculated.
Results
Twenty-one Shirodkar and ten McDonald operations were done. The mean (+/- standard deviation) precerclage cervical length was 2.7+/-0.9 cm and the postcerclage cervical length was 3.6+/-0.9 cm (P<.001, paired t test).
Conclusion
Prophylactic cerclage results in measurable increases in cervical length, which might contribute to the success of the procedure. Further study is needed to determine whether the degree of cervical lengthening after cerclage predicts term delivery.
PMID 10389730 10389730 DOI 10.1016/s0029-7844(98)00568-7 10.1016/s0029-7844(98)00568-7 Funai et al. 1999, Funai 1999
Cite this article
Funai, E. F., Paidas, M. J., Rebarber, A., O'Neill, L., Rosen, T. J., & Young, B. K. (1999). Change in cervical length after prophylactic cerclage. Obstetrics and gynecology, 94(1), 117-119. https://doi.org/10.1016/s0029-7844(98)00568-7
Funai EF, Paidas MJ, Rebarber A, O'Neill L, Rosen TJ, Young BK. Change in cervical length after prophylactic cerclage. Obstet Gynecol. 1999;94(1):117-119. doi:10.1016/s0029-7844(98)00568-7
Funai, E. F., et al. "Change in cervical length after prophylactic cerclage." Obstetrics and gynecology, vol. 94, no. 1, 1999, pp. 117-119.
To determine whether the degree of cervical lengthening after cerclage and whether serial follow-up measurements of cervical length after cerclage are predictive of pregnancy outcome. Eighty women whose primary physician determined that a prophylactic (n = 50) or urgent cerclage (n = 30) was indicated had transvaginal ultrasonographic evaluation before and after cerclage. Thereafter, most women had three additional transvaginal ultrasound examinations until 32 weeks' gestation. At each examination, the mean of three measurements was calculated. Statistical analyses were done by t test, analysis of variance, and logistic regression, with significance set at P <.05. The mean +/- standard deviation precerclage cervical length was 27.2 +/- 10.3 mm and after cerclage was 34.1 +/- 9.9 mm (n = 80, P <.001, paired t test). No significant association was found (r = -0.26) between the difference in cervical length (postcerclage - precerclage lengths) and pregnancy outcome. Patients with a prophylactic cerclage had a mean cervical length that was consistently longer in patients delivering at term compared with those who delivered preterm at 20 to 32 weeks' gestation. In the urgent cerclage group a significant difference in cervical length between those who delivered at term compared with preterm was evident only at 28 to 32 weeks. The increase in cervical length after cerclage is not predictive of term delivery. Serial cervical length measurements in the late second or early third trimester predict preterm birth but could provide earlier warning in patients with a prophylactic cerclage than in patients with urgent cerclage.
Our goal was to study the effect of therapeutic McDonald cerclage on cervical length with the use of transvaginal ultrasonography. Cervical length was measured serially in singleton pregnancies in which there were doubts regarding cervical competence. When shortening of the cervix was substantial before 27 weeks' gestation a McDonald cerclage was applied. Wilcoxon signed rank test was used, and 1-tailed P <.05 was considered significant. In the 34 pregnancies studied, the mean cervical length measured at a mean gestational age of 14 weeks had decreased significantly (P <.0001) from 42 mm (95% confidence interval 38-47) to 21 mm (95% confidence interval 19-23) at a mean gestational age of 20 weeks 5 days, when a cerclage was applied. After the cerclage the mean cervical length increased significantly (P <.0001) to 34 mm (95% confidence interval 30-38) at a mean gestational age of 22 weeks 1 day (95% confidence interval 21 weeks 1 day-23 weeks 2 days). Therapeutic McDonald cerclage results in a longer cervical length as measured by transvaginal ultrasonography.
The role of the cervix in the pathogenesis of premature delivery is controversial. In a prospective, multicenter study of pregnant women, we used vaginal ultrasonography to measure the length of the cervix; we also documented the incidence of spontaneous delivery before 35 weeks' gestation. At 10 university-affiliated prenatal clinics, we performed vaginal ultrasonography at approximately 24 and 28 weeks of gestation in women with singleton pregnancies. We then assessed the relation between the length of the cervix and the risk of spontaneous preterm delivery. We examined 2915 women at approximately 24 weeks of gestation and 2531 of these women again at approximately 28 weeks. Spontaneous preterm delivery (at less than 35 weeks) occurred in 126 of the women (4.3 percent) examined at 24 weeks. The length of the cervix was normally distributed at 24 and 28 weeks (mean [+/- SD], 35.2 +/- 8.3 mm and 33.7 +/- 8.5 mm, respectively). The relative risk of preterm delivery increased as the length of the cervix decreased. When women with shorter cervixes at 24 weeks were compared with women with values above the 75th percentile, the relative risks of preterm delivery among the women with shorter cervixes were as follows: 1.98 for cervical lengths at or below the 75th percentile (40 mm), 2.35 for lengths at or below the 50th percentile (35 mm), 3.79 for lengths at or below the 25th percentile (30 mm), 6.19 for lengths at or below the 10th percentile (26 mm), 9.49 for lengths at or below the 5th percentile (22 mm), and 13.99 for lengths at or below the 1st percentile (13 mm) (P < 0.001 for values at or below the 50th percentile; P = 0.008 for values at or below the 75th percentile). For the lengths measured at 28 weeks, the corresponding relative risks were 2.80, 3.52, 5.39, 9.57, 13.88, and 24.94 (P < 0.001 for values at or below the 50th percentile; P = 0.003 for values at the 75th percentile). The risk of spontaneous preterm delivery is increased in women who are found to have a short cervix by vaginal ultrasonography during pregnancy.
MRC/RCOG Working Party on Cervical Cerclage, 1993·Br J Obstet Gynaecol·
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.