The role of cervical cultures to guide perioperative antibiotics in cervical cerclage – a retrospective analysis of 65 consecutive cases

The Association between Shirodkar Cerclage and Preterm Premature Rupture of Membranes in Singleton Pregnancies

OBJECTIVE

The aim of this study was to estimate if preterm premature rupture of membranes in women with cerclage is due to the cerclage itself or rather the underlying risk factors for preterm birth in this population.

STUDY DESIGN

This was a retrospective cohort study of singleton pregnancies who underwent Shirodkar cerclage by a single maternal-fetal medicine practice between 2005 and 2019. The control group was an equal number of randomly selected women with a singleton gestation who had a prior preterm birth and were treated with 17-OH-progesterone but no cerclage. Patients with major uterine anomalies or fetal anomalies were excluded. The primary outcome was preterm premature rupture of membranes prior to 34 weeks. Chi-square and logistic regression were used.

RESULTS

A total of 350 women with cerclage (154 [44%] history-indicated, 137 [39%] ultrasound-indicated, and 59 [17%] exam-indicated) and 350 controls were included. Preterm premature rupture of membranes prior to 34 weeks did not differ between the groups (8.9% in cerclage vs. 6.0% in controls, p = 0.149, adjusted odds ratio 0.62, 95% confidence interval: 0.24-1.64) nor between the different cerclage indications (9.1% of history-indicated, 7.3% of ultrasound-indicated, and 11.9% of exam-indicated, p = 0.582). This study had 80% power with an α error of 0.05 to detect an increase in preterm premature rupture of membranes prior to 34 weeks from 6.0% in the control group to 12.0% in the cerclage group.

CONCLUSION

Cerclage does not increase the risk of preterm premature rupture of membranes prior to 34 weeks compared with other women at increased risk of preterm birth. The observed association between cerclage and preterm premature rupture of membranes is likely due to underlying risk factors and not the cerclage itself. The risk of preterm premature rupture of membranes prior to 34 weeks in women with cerclage is 10% or less and does not appear to differ based on cerclage indication.

KEY POINTS

· Cerclage does not increase the risk of PPROM.. · Risk of PPROM with cerclage is approximately 10%.. · Risk does not appear to vary by indication..

Effect of adjunctive vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy: a randomized controlled trial

OBJECTIVE

To evaluate the effect of adjunctive use of vaginal progesterone after McDonald cerclage on the rate of second-trimester abortion in singleton pregnancy.

METHODS

A randomized controlled trial at Woman's Health Hospital, Assiut University, Egypt, between April 2017 and March 2019 enrolled women eligible for McDonald cerclage. After cerclage, participants were randomly assigned to receive progesterone (400 mg pessary) once daily until 37 weeks or no progesterone. The primary outcome was rate of abortion before 28 weeks. Secondary outcomes included gestational age at delivery, preterm delivery, mean birthweight, Apgar score, and admission to the neonatal intensive care unit (NICU).

RESULTS

The rate of spontaneous abortion was higher in the no-progesterone group (P=0.016). Mean gestational age and mean birthweight was higher in the progesterone group (P<0.001 and P=0.002, respectively). The frequency of preterm neonates, neonates with Apgar score less than 7, and admission to NICU was higher in the progesterone group than in the no-progesterone group (P=0.005, P=0.008, and P=0.044, respectively).

CONCLUSION

Adjunctive use of vaginal progesterone after McDonald cerclage was found to decrease the frequency of second-trimester abortion and to improve perinatal outcomes in singleton pregnancy. Clinicaltrials.gov: NCT02846909.