[Fetal curarization by umbilical cord puncture during pregnancy]

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Pharmacology

Context:

• Long fetal procedures like in utero exchange transfusion or detailed fetal imaging require fetal immobility.
• Achieving fetal immobility has traditionally relied on maternal anesthesia, posing potential risks.
• Direct fetal intervention offers an alternative approach to managing fetal status during procedures.

Purpose:

• To describe a novel technique for inducing temporary fetal neuromuscular blockade.
• To evaluate the safety and efficacy of direct umbilical vein injection of vecuronium in fetuses.
• To compare this technique with maternal anesthesia for fetal immobility.

Summary:

• Two cases successfully utilized direct umbilical vein injection of 0.1 mg/kg vecuronium under ultrasonographic guidance for fetal immobility.
• The neuromuscular blockade lasted approximately 2 hours, with spontaneous return of fetal movements.
• Transient fetal bradycardia was the only noted side effect, with no other adverse events observed.

Impact:

• Direct fetal injection of muscle relaxants presents a simpler and potentially safer alternative to maternal anesthesia for achieving fetal immobility.
• This technique may improve safety profiles for both mother and fetus during complex intrauterine interventions.
• Further research could establish this method as a standard for fetal procedural management.