Plasma cholinesterase changes during the puerperium.

Changes in plasma cholinesterase activity during the puerperium were studied in 16 women who received epidural analgesia for labour followed by vaginal delivery, and in five women who underwent elective Caesarean section under epidural analgesia. A consistent fall in cholinesterase activity was demonstrated during the first 2 to 3 days post partum, followed by a rise to approximately normal nonpregnant values by the end of the puerperium. An additional patient who manifested prolonged paralysis following an emergency Caesarean section under general anaesthesia, including a suxamethonium infusion, was also studied. Possible mechanisms by which the transient decrease in cholinesterase activity is produced, and its clinical significance, are discussed.