SMFM and Choosing Wisely: Practices That Doctors and Patients Should Question image

SMFM and Choosing Wisely: Practices That Doctors and Patients Should Question


The purpose of the Choosing Wisely campaign is to promote discussion between patients and clinicians with the goal of preventing unnecessary medical interventions. SMFM has provided a list of pregnancy specific practices that should be avoided because evidence of sufficient benefit is lacking. Summary of the related source guidelines and links can be found in the ‘Related ObG Topics’ section.


  • Do not order thrombophilia testing for women with histories of pregnancy loss, fetal growth restriction (FGR), preeclampsia and abruption
    • Causal association between thrombophilia related polymorphisms, (including MTHFR) and adverse pregnancy outcomes are not supported by the literature
    • Limit the ordering of antiphospholipid antibodies to lupus anticoagulant, anticardiolipin antibodies and beta 2 glycoprotein antibodies, based on indication
  • Do not manage a pregnancy based on NIPS result alone
    • Confirm positive NIPS results before proceeding
    • NIPS is a screening test and not a definitive diagnosis
    • False positives and negatives can occur
    • “Adequate pretest counseling must be provided to explain the benefits and limitations”
  • Do not screen for FGR with Doppler blood flow studies
    • Standards do not currently exist that can
      • Discern an abnormal test
      • Identify optimum gestational age for testing
      • Determine appropriate technique
    • However, in the setting of suspected FGR, fetal assessment that includes UA Doppler studies is beneficial
  • Do not use progestogens in uncomplicated multifetal gestations
    • No evidence that progestogens reduce the incidence of preterm birth in this population
  • Do not perform cervical length screening in patients who do not have symptoms <16 weeks or >24 weeks
    • The appropriate time frame is between 16 and 24 weeks of gestation
  • Do not perform antenatal testing for GDM well controlled by diet
    • If GDM is well-controlled by diet and glucose monitoring alone, risk for stillbirth is not increased
    • Antenatal monitoring should be reserved for those patients where fetal assessment is indicated for other reasons
  • Do not restrict activity for preterm birth prevention
    • Activity restriction is not advised even for women at high risk for preterm birth due to lack of evidence of benefit and possible harms
  • Do not order serum aneuploidy screening after NIPS
    • While serum screening may identify some additional aneuploidies, “the yield is too low to justify this test if cfDNA screening has already been performed”
  • Do not routinely order maternal serologic studies for CMV and toxoplasmosis during pregnancy
    • These tests have poor predictive value in otherwise normal pregnancies
    • Potential harms may occur due to false positive results
  • Do not recommend invasive testing in women with low risk aneuploidy screening results and isolated ‘soft markers’, such as echogenic intracardiac focus (EIF) or isolated choroid plexus cyst (CPC)
    • Describe ‘soft marker’ finding as ‘not clinically significant’ or ‘normal variant’
  • Do not perform serial cervical length measurement following cerclage placement
    • There is no evidence that cervical length monitoring following a cerclage improves outcomes, despite cervical shortening being associated with increased risk for preterm birth
  • Do not order MTHFR polymorphism genotyping in the clinical evaluation for thrombophilia, recurrent pregnancy loss, or for at-risk family members
    • Two polymorphic variants are known to decrease enzyme activity: 677C>T and 1298A>C 
    • Older studies suggested that MTHFR genotype status may be related to increased risk of venous thrombosis, coronary heart disease, recurrent pregnancy loss and adverse pregnancy outcomes but more recent analyses have not demonstrated consistent associations  
  • Do not screen for subclinical hypothyroidism in pregnant women who are asymptomatic
    • RCTs have not demonstrated treatment benefit for subclinical hypothyroidism
    • A recent secondary analysis of a large RCT did not identify a difference between prepregnancy TSH < 2.5 vs ≥5 mIU/L and preterm delivery, GDM or preeclampsia
  • Do not use AFI for diagnosis of oligohydramnios in the third trimester
    • Deepest vertical pocket of <2 is preferred
    • AFI is associated with more women being identified with oligohydramnios, but without any significant benefit in perinatal outcome
  • Do not routinely order NIPS microdeletion studies
    • Most of these microdeletion syndromes are rare in the general population and therefore positive predictive values will be very low
  • Do not order routine serum biomarker testing for preeclampsia (e.g., PlGF or sFlt-1) or preterm birth (e.g. various cytokines) risk assessment in otherwise asymptomatic patients
    • Preterm birth biomarkers are not recommended due to limited utility
    • Preeclampsia biomarkers are not recommended due poor predictive value
    • Evidence of clinical utility is lacking (e.g., impact of low-dose aspirin on outcomes based on positive screening results)
    • Risk of harms from potential interventions
  • Do not deliver for suspected macrosomia in a nondiabetic patient <39w0d weeks of gestation
    • Risk for increased adverse perinatal outcomes for deliveries <39 weeks
    • EFWs are not precise and data regarding benefit of earlier delivery remain limited
  • Do not routinely exclude women with two prior low transverse cesareans for TOLAC
    • Absolute increased risk of any major complication remains low
    • Chance of vaginal birth similar to one prior cesarean
  • Do not order GBS culture in 3rd trimester based on GBS bacteriuria during pregnancy
    • GBS bacteriuria at ≥105 CFU/mL
      • Requires maternal antepartum treatment
      • Treat with intrapartum antibiotic prophylaxis at the time of birth
    • GBS bacteriuria at <105 CFU/mL
      • Does not require maternal antepartum treatment
      • Treat with intrapartum antibiotic prophylaxis at the time of birth

Learn More – Primary Sources:

SMFM Choosing Wisely: Things Physicians and Patients Should Question

Choosing Wisely®: Promoting conversations between patients and clinicians