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)

ACOG and Universal Screening for Cystic Fibrosis – What You Need to Know

CLINICAL ACTIONS:

Genetic screening for Cystic Fibrosis (CF) has been recommended by ACOG and ACMG for over a decade.

• Offer CF screening to all women of reproductive age, not just those in higher risk groups
• Document previous CF screening results
  • Genetic testing does not need to be repeated in subsequent pregnancies if already on record
• Expanded mutation panels beyond the ‘ACMG 23’ can be considered to increase sensitivity
  • DNA sequencing of the CFTR gene is not considered ‘appropriate’ for routine carrier screening and should be reserved for particular circumstances in conjunction with genetic counseling (see below in key points)
• Refer for genetic counseling if both partners are CF carriers
  • CF is an autosomal recessive disorder and if both partners are affected, the risk to offspring is ¼ or 25%

SYNOPSIS:

Initially, prenatal screening for CF was limited to women from high risk groups, non-Hispanic whites and those of Ashkenazi Jewish background. However, as it becomes more difficult to identify specific racial groups and ethnicities, ACOG guidance is clear that all women of reproductive age should be screened to determine their carrier status. There are several genetic tests currently available that can sequence the entire CFTR gene, providing a clinical report for hundreds of CF disease causing mutations.  While Committee Opinion 691 still mentions the original ACMG 23 mutation panel,  expanded mutation panel analysis can be considered to help improve test sensitivity particularly among non-Caucasians.

KEY POINTS:

• Full gene sequencing of the CFTR gene should be reserved for patients who meet the following criteria:
  • Personal history of CF
  • Family history of CF
  • Males with CBAVD
  • Newborns with positive newborn screening results when mutation panel testing is negative
• Newborn screening for CF in newborns does not replace maternal screening
  • A negative newborn screen for CF cannot identify parental carriers
• Diagnosis code: Z31.430

Learn More – Primary Sources:

ACOG Committee Opinion 690: Carrier Screening in the Age of Genomic Medicine

ACOG Committee Opinion 691: Carrier Screening for Genetic Conditions

Expanded Carrier Screening in Reproductive Medicine—Points to Consider: A Joint Statement of the ACMG, ACOG, NSGC, PQF, and SMFM

Locate a Genetic Counselor or Genetics Services:

Genetic Services Locator-ACMG

Genetic Services Locator-NSGC

Genetic Services Locator-CAGC

Locate an MFM Specialist:

Locate a Maternal Fetal Medicine Specialist: SMFM