OBJECTIVE: Animal work suggests that maternal oxytocin secretion is influenced by the secretion of endogenous opioids in pregnancy. Spontaneous labour and pre-labour uterine activity follow a 24-hour rhythm the origin of which has not been explained but may be related to diurnal changes in oxytocin secretion. This study was performed to document the changes over a 24-hour period in maternal oxytocin and beta-endorphin secretion. DESIGN: A 4-hourly blood profile was undertaken for a 24-hour period. PATIENTS: Sixteen women with singleton pregnancies of more than 36 weeks gestation and 10 women with pregnancies in the mid trimester were studied. MEASUREMENTS: Blood was sampled 4-hourly for 24 hours beginning at 1200 h. Oxytocin was measured in all patients and beta-endorphin-like immunoreactivity was measured in 15 patients. RESULTS: A simple index was defined for comparing night-time levels to daytime levels for both oxytocin and beta-endorphin. In all cases more than 36 weeks gestation the index was positive for oxytocin (night-time levels were higher) and in all cases the index was negative for beta-endorphin (night-time levels were lower). In the mid trimester women all values of the index for oxytocin were positive but in the beta-endorphin group equal numbers demonstrated a positive or a negative index. CONCLUSIONS: Reciprocal 24-hour rhythms were demonstrated between oxytocin and beta-endorphin; however, it is not clear whether this relationship is causal.
OBJECTIVE: Animal work suggests that maternal oxytocin secretion is influenced by the secretion of endogenous opioids in pregnancy. Spontaneous labour and pre-labour uterine activity follow a 24-hour rhythm the origin of which has not been explained but may be related to diurnal changes in oxytocin secretion. This study was performed to document the changes over a 24-hour period in maternal oxytocin and beta-endorphin secretion. DESIGN: A 4-hourly blood profile was undertaken for a 24-hour period. PATIENTS: Sixteen women with singleton pregnancies of more than 36 weeks gestation and 10 women with pregnancies in the mid trimester were studied. MEASUREMENTS: Blood was sampled 4-hourly for 24 hours beginning at 1200 h. Oxytocin was measured in all patients and beta-endorphin-like immunoreactivity was measured in 15 patients. RESULTS: A simple index was defined for comparing night-time levels to daytime levels for both oxytocin and beta-endorphin. In all cases more than 36 weeks gestation the index was positive for oxytocin (night-time levels were higher) and in all cases the index was negative for beta-endorphin (night-time levels were lower). In the mid trimester women all values of the index for oxytocin were positive but in the beta-endorphin group equal numbers demonstrated a positive or a negative index. CONCLUSIONS: Reciprocal 24-hour rhythms were demonstrated between oxytocin and beta-endorphin; however, it is not clear whether this relationship is causal.
Authors: Miguel Angel Luque-Fernandez; Cande V Ananth; Sixto E Sanchez; Chun-fang Qiu; Sonia Hernandez-Diaz; Unnur Valdimarsdottir; Bizu Gelaye; Michelle A Williams Journal: Ann Epidemiol Date: 2014-12 Impact factor: 3.797
Authors: Julia von Ehr; Nina Wiebking; Sudip Kundu; Constantin von Kaisenberg; Peter Hillemanns; Philipp Soergel Journal: Geburtshilfe Frauenheilkd Date: 2018-08-20 Impact factor: 2.915