TY - JOUR

T1 - Intrapartum transfer of oxytocin across the human placenta

T2 - An ex vivo perfusion experiment

AU - Nathan, Nina Olsen

AU - Hedegaard, Morten

AU - Karlsson, Gosta

AU - Knudsen, Lisbeth E.

AU - Mathiesen, Line

PY - 2021

Y1 - 2021

N2 - Introduction: Investigation of the maternal to fetal transfer of oxytocin across the dually perfused term human placenta.Methods: Human placentae obtained from term singleton pregnancies were utilized in a dual recirculating model of ex vivo placental perfusion. Six placentae from women delivering by elective cesarean at term were perfused, one blank and five with the test substance synthetic oxytocin (0.8 ng/mL) (OX) added to the maternal perfusate for 180 min. Antipyrine was used as positive control to validate overlap of the maternal and fetal circuits. The concentration of OX was determined by radioimmunoassay.Results: A fall in maternal concentration of OX was seen throughout the experiment. At 90 min of perfusion a state of equilibrium was reached between maternal and fetal concentrations; however after 180 min the fetal concentration of OX was higher than that of the maternal. 31 % of the test substance was accounted for at the end of the experiment - suggesting OX protein binding and a high degree of oxytocinase activity.Discussion: The ex vivo perfusion experiments revealed low transfer of OX to the fetal circuit below physiologically relevant concentrations.

AB - Introduction: Investigation of the maternal to fetal transfer of oxytocin across the dually perfused term human placenta.Methods: Human placentae obtained from term singleton pregnancies were utilized in a dual recirculating model of ex vivo placental perfusion. Six placentae from women delivering by elective cesarean at term were perfused, one blank and five with the test substance synthetic oxytocin (0.8 ng/mL) (OX) added to the maternal perfusate for 180 min. Antipyrine was used as positive control to validate overlap of the maternal and fetal circuits. The concentration of OX was determined by radioimmunoassay.Results: A fall in maternal concentration of OX was seen throughout the experiment. At 90 min of perfusion a state of equilibrium was reached between maternal and fetal concentrations; however after 180 min the fetal concentration of OX was higher than that of the maternal. 31 % of the test substance was accounted for at the end of the experiment - suggesting OX protein binding and a high degree of oxytocinase activity.Discussion: The ex vivo perfusion experiments revealed low transfer of OX to the fetal circuit below physiologically relevant concentrations.

KW - Human

KW - Ex vivo techniques

KW - Placental perfusion

KW - Maternal-fetal exchange

KW - Placenta/drug exposure

KW - Uterotonics

KW - BRAIN-BARRIER PERMEABILITY

KW - LABOR

KW - AUTISM

KW - ALBUMIN

KW - RISK

U2 - 10.1016/j.placenta.2021.07.289

DO - 10.1016/j.placenta.2021.07.289

M3 - Journal article

C2 - 34329968

VL - 112

SP - 105

EP - 110

JO - Placenta

JF - Placenta

SN - 0143-4004

ER -