Cervical Cerclage – Professional Recommendations

CLINICAL ACTIONS:

ACOG defines cervical insufficiency as “the inability of the uterine cervix to retain a pregnancy in the absence of the signs and symptoms of clinical contractions, or labor, or both in the second trimester.” In addition, ACOG separates out indication for cerclage in to 3 categories

  • History: ≥1 of the following
    • Second trimester pregnancy losses related to painless cervical dilation and no history of labor or abruption
    • Previous second trimester cerclage for painless cervical dilation
  • Physical Examination: Also known as ‘physical examination–indicated cerclage’, ‘rescue cerclage’ and ’emergency cerclage’
    • Patient presents with painless second trimester cervical dilation
  • Ultrasound: Cervical length shortening and history of preterm birth
    • Singleton pregnancy
    • Prior spontaneous preterm birth (<34 weeks)
    • Cervical length:  <25 mm (at <24 weeks)

SMFM states that cerclages are effective in woman based on the following indications:

  • History indicated: 3 or more PTBs or second-trimester losses.
  • Ultrasound indicated: ≥1 early PTB (defined as delivery between 17w to 33w6d), and cervical length (CL) <25 mm on transvaginal ultrasound (TVUS) before 24 weeks

Timing of Cerclage Placement

  • History-indicated cerclage
    • Place between 12 and 14 weeks after confirmation of pregnancy viability
  • Ultrasound or exam-indicated cerclage
    • May be placed prior to 23 weeks

Risk Factors

  • Prior PTB
  • Repeated cervical dilation
  • Cervical procedures (including cone and LEEP)
  • Cervical laceration
  • Urogenital abnormalities

SYNOPSIS:

Clinically, cervical insufficiency is painless dilation and recurrent mid-trimester losses without signs of preterm labor (PTL), PPROM, or infection. Patient history may include superimposed symptoms (i.e. bleeding, pressure), therefore a judicious review of records is advised.  Those with a history of prior preterm birth can benefit from cervical length screening to appropriate guide selected patients for cerclage.

KEY POINTS:

Ultrasound Indicated Cerclage with Prior History of Preterm Birth or Second Trimester Losses (SMFM)

  • CL surveillance
    • Begin at 16 weeks
    • Perform every 2 weeks
    • CL measurement 25-29 mm: Perform weekly
  • Offer cerclage when
    • CL <25 mm prior to 23w0d weeks and
    • History of spontaneous PTB at 17w0d to 33w6d
  • 17–alpha hydroxyprogesterone caproate (17-OHPC)
    • Note: Cerclage placement or presence should not alter recommendations
  • Evidence from research studies
    • There is no difference in efficacy of McDonald versus Shirodkar techniques

Special Circumstances

  • Diagnosis of cervical insufficiency is unclear
    • Consider close screening starting at 16 weeks in place of history indicated cerclage placement
  • Very early losses
    • Consider beginning screening <16 weeks if there is a history of very early second trimester losses

‘Emergency’ Cerclage (Exam indicated)

  • There is literature, including a meta-analysis (Obstet Gynecol, 2015), to support ’emergency’ or ‘rescue’ cerclage
    • Neonatal survival
      • Cerclage: 71% survival
      • No cerclage: 43% survival
      • Relative risk 1.65 (95% CI 1.19–2.28)
    • Prolongation of pregnancy
      • Mean difference: 33.98 days (95% CI, 17.88 to 50.08)
    • Authors note significant limitations including quality of data and only 1 RCT included

After clinical examination to rule out uterine activity, or intraamniotic infection, or both, physical examination-indicated cerclage placement (if technically feasible) in patients with singleton gestations who have cervical change of the internal os may be beneficial

SMFM Choosing Wisely Campaign

  • SMFM recommends the following after cerclage placement
    • Do not perform serial cervical length measurements
    • There is no evidence that cervical length monitoring following a cerclage improves outcomes, despite cervical shortening being associated with increased risk for preterm birth

Learn More – Primary Sources:

SMFM: Cervical cerclage for the woman with prior adverse pregnancy outcome

ACOG Practice Bulletin 142: Cerclage for the Management of Cervical Insufficiency

Physical Examination–Indicated Cerclage: A Systematic Review and Meta-analysis

Updated Outcomes Data for Neonates less than 500 Grams at Birth

BACKGROUND AND PURPOSE:

  • There is limited data on extremely low birthweight newborns
  • Bashir et al. (Am J Perinatol, 2017) describe survival, short-term, and long-term morbidities of neonates < 500g

METHODS:

  • Retrospective cohort study
  • Neonatal Follow-Up Program (NFUP) at British Columbia’s Women’s Hospital and Health Centre (BCWH)
    • Prospectively enrolls neonates with birth weight ≤ 800 g
    • Conducts multidisciplinary neurodevelopmental assessments at ages 4, 8, and 18 months corrected age (CA), and at 3 and 4.5 years chronological age since 1983
    • The first survivor with birth weight < 500 g was born in 1985
  • Primary objectives
    • Calculated survival and morbidity rates as well as neurodevelopmental impairment rates at 4.5 years of neonates < 500g
  • Secondary objective
    • Compare outcomes of small for gestational age (SGA) infants against entire cohort where <500 g is appropriate for gestational age

RESULTS:

  • Data from 549 neonates with birth weight < 500g was collected
  • Among liveborns
    • 180 (83%) died in the delivery room
    • 17 (8%) died in the NICU
    • 21 (10%) survived
  • Among all births, 3.8% (21/549) survived
  • Of NICU survivors
    • Median birth weight was 460 g
    • Median gestational age was 25.9 weeks (range: 22.6-30.3 weeks)
    • 71% were inborn | 50% male | 75% were SGA
  • 20% were a twin or multiple
  • Complications – Leading Short Term Morbidities
    • Branchopulmonary dysplasia (91%)
    • Culture proven sepsis (50%)
    • Retinopathy of prematurity (41%)
    • Severe brain injury (22%)
  • Complications – Long Term Morbidities
    • 27% had no long-term impairment
    • 23% had one, 23% had two, 18% had three, and 9% had four impairments in motor, cognitive, vision, and/or hearing domains
  • At 4.5 years
    • 29% had visual impairment
    • 10% wore hearing aids
    • 50% had an IQ <70
    • 18% cerebral palsy
    • 68% had low motor scores

CONCLUSION:

  • Approximately 4% of births <500 g survived, with all survivors having short-term morbidities
  • 27% of neonates survived without long-term impairment

Learn More – Primary Sources:

Survival, Short-Term, and Long-Term Morbidities of Neonates with Birth Weight < 500 g

Antenatal Corticosteroids – When to Administer?

The appropriate use of antenatal corticosteroids improves neonatal outcomes, including decreased severity and/or frequency of respiratory distress syndrome (RDS), intracranial hemorrhage, necrotizing enterocolitis and death. Antenatal corticosteroids, when appropriate, are administered in a clinical setting where patients are at risk for preterm delivery within 7 days, irrespective of membrane status and fetal number.

Clinical Actions:

Risk of preterm delivery within 7 days

Between 24w0d to 33w6d – ‘Recommended’

    • Single course of corticosteroids

Between 23w0d and 23w6d – ‘May be Considered’

  • 23w0d to 23w6d
    • Single course of corticosteroids
  • 22w0d to 22w6d
    • Single course of corticosteroids

Note: ACOG and SMFM revised recommendation states

Antenatal corticosteroids may be considered at 22 0/7 weeks to 22 6/7 weeks of gestation if neonatal resuscitation is planned and after appropriate counseling

Some families may choose to forgo resuscitation and support after appropriate counseling

Between 20w0d and 21w6d – ‘Not Recommended’

  • Antenatal corticosteroids are not recommended due to lack of data suggesting benefit

Late preterm (34w0d – 36w6d)

ACOG 

  • If no previous corticosteroids
    • Single course of betamethasone
    • Not indicated in women diagnosed with clinical chorioamnionitis

SMFM 

  • Single course of betamethasone in specific populations
    • Population included in ALPS trial: Recommended
      • Nonanomalous singleton gestation
      • High risk for preterm delivery (medically indicated or spontaneous)
      • No prior antenatal steroids
    • Select populations not in the original ALPS trial: Suggest consideration for use in the following clinical scenarios
      • Multiple gestations reduced to a singleton gestation ≥14w0d
      • Fetal anomalies
      • Expected to deliver in less than 12 hours
    • Low likelihood of delivery <37 weeks: Recommend against
    • Pregestational diabetes: Recommend against due to risk for worsening neonatal hypoglycemia

Repeat or Rescue Courses

  • Regularly scheduled repeat courses or serial (> 2) courses
    • Not recommended
  • If a patient has received one prior course of corticosteroids > 14 days ago, is less than 34w0d gestation and is at risk of preterm delivery within 7 days
    • a single repeat course of corticosteroids should be considered (change from previous ‘may’)
    • Rescue course corticosteroids could be provided as early as 7 days from the prior dose, if indicated by the clinical scenario (based on Cochrane meta-analysis)
  • Preterm prelabor rupture of membranes (PPROM)
    • There is insufficient evidence to make a recommendation for or against repeat or rescue courses

Dose and Regimen: give first dose even if 2nd dose unlikely

  • Betamethasone: 12 mg IM, 2 doses 24 hours apart
  • Dexamethasone:  6 mg IM, 4 doses 12 hours apart

Learn More – Primary Sources

ACOG Committee Opinion 713: Antenatal Corticosteroid Therapy for Fetal Maturation

ACOG Practice Advisory: Use of Antenatal Corticosteroids at 22 Weeks of Gestation

ACOG Practice Bulletin No. 171 : Management of Preterm Labor

Society for Maternal-Fetal Medicine (SMFM) Consult #58: Use of Antenatal Corticosteroids for Individuals at Risk for Late Preterm Delivery

Society for Maternal-Fetal Medicine Special Statement: Quality metrics for optimal timing of antenatal corticosteroid administration – American Journal of Obstetrics & Gynecology (ajog.org)