Fetal curarization by umbilical cord puncture during pregnancy]

Two cases of foetal neuromuscular blockade carried out to obtain foetal immobility during long procedures (in utero foetal exchange transfusion, foetal imaging) are reported. The blockade was carried out in the operating theatre, the mother being awake. Foetal weight had been estimated according to usual echographic parameters. After a long needle had been inserted in the umbilical vein under the guidance of ultrasonography, 0.1 mg.kg-1 vecuronium was injected. Muscle paralysis lasted for about 2 hours in both cases, foetal movements returning spontaneously. There were no side effects due to this technique, a transient foetal bradycardia excepted. Foetal neuromuscular blockade by direct cord injection of muscle relaxants seems to be a simpler, and perhaps safer, technique than obtaining foetal immobility by maternal anaesthesia.