3RD-TRIMESTER POMC DISREGULATION PREDICTS USE OF ANESTHESIA AT VAGINAL DELIVERY

In a prospective study, third trimester plasma levels of BE and ACTH w ere determined in 58 women who delivered vaginally. Peptide regulation was compared between subjects who used conduction anesthesia at deliv ery and subjects who did not. Third trimester levels of maternal BE an d ACTH were significantly related; however, the relationship was signi ficant only in subjects who did not receive conduction anesthesia (n = 24) at delivery. The normal corelease pattern between BE and ACTH in subjects receiving conduction anesthesia (n = 34) during birth was unc oupled. The use of conduction analgesia during vaginal delivery was si gnificantly related to a disregulation index created to quantify the B E-ACTH release pattern. Uncoupled ACTH and BE patterns may result from modified control of proopiomelanocortin (POMC) expression during preg nancy or unique proteolytic processing of POMC, and may alter pain tol erance during delivery.