BACKGROUND AND PURPOSE:

• Direct exposure of fetal bowel to amniotic fluid can trigger significant ischemic and inflammatory processes
• Based on experiments in animals, an amnioexchange procedure may reduce inflammation
• Luton et al. (BJOG, 2019) investigated the benefits of using this amnioexchange procedure for fetal gastroschisis in humans

METHODS:

• Prospective, interventional, randomized study (RCT)
• Participants
  • Pregnant women >18 years of age and ≥20 weeks gestation
  • Singleton pregnancy
  • Fetal gastroschisis (isolated)
• Intervention (in utero)
  • Amnioexchange procedure
    • Started at 30 weeks q2weeks | 300 ml amniotic fluid removed via 18 gauge needle and same volume of saline replaced
  • A sham procedure
    • 1 ml saline injected subQ at the site and using a perfusion bag, sounds and movements were simulated similar to amnioexchange arm
• In both arms
  • Patients draped in a way that they were blinded
  • Steroid injections at 30 weeks
  • Postnatal minimal enteral feeding
• Primary outcome
  • A composite variable based on the duration of ventilation and parenteral nutrition
• Secondary outcomes
  • Effectiveness and safety of the amnioexchange procedure, including
    • The rate of perinatal death
    • Time to full enteral feeding
    • Primary closure
    • Late feeding disorders

RESULTS:

• Study stopped early, midway through recruitment due to
  • Failure to recruit sufficient cases
  • Failure at the last analysis to show any improvement in the amnioexchange arm
  • Concern about side effects
• 64 patients were randomized
  • 34 in amnioexchange group | 30 in placebo group
• Primary outcome
  • No difference in the composite criteria between groups
• Secondary outcome
  • No significant between-group differences in pregnancy outcome or complications
• There was a relationship between digestive enzymes and inflammation factors in the amniotic fluid
  • Bile acid levels are associated with both ferritin and interleukin 1β (IL1β); P < 0.01

CONCLUSION:

• The amnioexchange protocol used in this study is not an option for fetal care in humans
• Future gastroschisis research should focus on modalities to reduce inflammatory pathways

Learn More – Primary Sources:

A randomised controlled trial of amnioexchange for fetal gastroschisis

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