[Pharmacologic induction of fetal immobilization for prenatal diagnostic-therapeutic procedures].

Neuro-muscular blocking agents are currently administered to the fetus during intrauterine procedures, in order to freeze fetal movements and to avoid traumatic effects. The authors have evaluated three drug regimens (Pancuronium, Vecuronium, Atracurium), both via the intramuscular and the intravascular route of administration to the fetus. The time lapse between injection and disappearance of movements and the duration of paralysis have shown no significant differences for each group. The duration of fetal immobilization, on the other hand, has resulted excessively long for the necessity of the procedure. The authors speculate that immaturity of fetal metabolism can be responsible for the prolonged action of the drug. No side effect related to paralysis have been recorded at birth and after two years follow-up.