Management of Progressive Cervical Shortening Despite Progesterone

Evaluation and Intervention

The Society for Maternal-Fetal Medicine (SMFM) recommends that when cervical shortening is <11-15 mm, a physical exam should be considered because the prevalence of cervical dilation is very high 1
For a patient with a cervical length of 13 mm, there is a 30-70% probability of already having cervical dilation ≥1 cm, making her a candidate for indicated cerclage 2, 1
The SMFM guideline suggests that cerclage may be considered when the cervix is <10 mm based on shared decision-making 2, 1
Continuing progesterone vaginal 400 mg daily after cerclage is recommended, as it has been shown to reduce preterm birth <34 weeks (2.2% vs 18.4%) and <37 weeks (9.1% vs 29.7%) 1
For patients with a history of preterm birth and cervical length ≤25 mm, progesterone vaginal reduces preterm birth <33 weeks (RR 0.54) and neonatal morbidity and mortality (RR 0.41) 3, 4

Cerclage placement in patients with progressive cervical shortening despite progesterone is associated with increased latency to delivery (34 3/7 vs 27 2/7 weeks; P<0.001) 2
The decision to place a cerclage should be based on shared decision-making, considering the patient's individual risk factors and the potential benefits and risks of the procedure 2, 1

Continuing progesterone vaginal 400 mg daily is recommended, regardless of whether a cerclage is placed or not, as the evidence suggests additive benefit 1, 4, 3
Frequent ultrasonographic follow-up is prudent in cases with documented progressive cervical shortening, although there is no high-quality evidence on the optimal frequency of follow-up 2, 1

The American College of Obstetricians and Gynecologists recommends emergency cerclage in patients with fetal membranes visible at or past the external cervical os in the absence of uterine contractions, preterm premature rupture of membranes (PPROM), or intra-amniotic infection at less than 24 weeks of gestation 5, 6
Emergency cerclage is indicated when there is cervical dilation with visible fetal membranes in the second trimester (typically before 24 weeks) without signs of infection, labor, or PPROM 5, 6
Contraindications for emergency cerclage include preterm premature rupture of membranes 5, 6 and gestational age beyond 24 weeks 5, 6

Tocolytics may be considered to prevent uterine contractions during and immediately after the procedure 5, 6

Observational and randomized controlled studies show that emergency cerclage is associated with pregnancy prolongation 5, 6
Emergency cerclage is associated with increased live births 5, 6
Emergency cerclage is associated with improved neonatal survival compared to expectant management 5, 6
The American College of Obstetricians and Gynecologists suggests consideration of continuation of vaginal progesterone after cerclage placement, as limited evidence suggests reduced spontaneous preterm birth rates 7, 8

A multidisciplinary approach involving obstetricians, maternal-fetal medicine specialists, and neonatologists is recommended for counseling and decision-making 5, 6