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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 22w0d 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)

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 and end at 24 weeks
    • Perform every 1 to 2 weeks
  • Offer cerclage when
    • CL <25 mm prior to 23w0d weeks and
    • History of spontaneous PTB at 17w0d to 33w6d
  • Evidence from research studies
    • There is no difference in efficacy of McDonald versus Shirodkar techniques

‘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 to 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

Additional Interventions

  • Evidence does not support use of the following after cerclage placement
    • Serial cervical length measurements
    • Antibiotics
    • Prophylactic tocolysis

Cerclage Removal

  • Remove transvaginal McDonald cerclage at 36 to 37 weeks
  • Cesarean delivery planned for ≥39 weeks
    • May be removed at time of delivery
    • Consider possibility of spontaneous labor between 37 and 39 weeks
  • McDonald cerclage may be removed in the office
  • PPROM
    • Removal or retention “is reasonable”
    • Prolonged antibiotic prophylaxis >7 days not recommended if suture is retained
  • Preterm labor
    • Diagnosis may be more difficult with cerclage in place

Routine management of preterm labor should be followed for patients with symptomatic preterm labor

If cervical change, painful contractions, or vaginal bleeding progress, cerclage removal is recommended

Learn More – Primary Sources:

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

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

MFM: The role of routine cervical length screening in selected high- and low-risk women for preterm birth prevention

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