Melatonin concentration in umbilical cord blood depends on mode of delivery.
OBJECTIVE
Melatonin (MT) is rapidly transferred from the maternal to fetal circulation in humans. There is little knowledge about factors which influence the MT concentration (MTc) in the umbilical cord (UC) blood during delivery. The aim of our study was to evaluate the MT status in the UC blood according to the time and mode of delivery.


METHODS
Blood samples from umbilical artery (UA) and vein (UV) were collected from spontaneous vaginal deliveries (SVD, n=122) and cesarean section deliveries (CSD, n=188). MTc was measured using a commercially available radioimmunoassay.


RESULTS
The MTc was not significantly different between UA and UV blood both at daytime and at nighttime (p=0.216 and p=0.440, respectively). Both in UA and in UV, the MTc was significantly higher at nighttime than at daytime (p<0.0001). Compared with the CSD group, MTc in the SVD group was significantly higher both at night- and daytime (p<0.05). MTc both in UA and in UV was found to be not significantly different between patients with and without risk factors for stress including pregnancy complications (e.g., preeclampsia) and intrapartum complications (e.g., emergency section, pathological doppler, and pathological cardiotocography) (p>0.05).


CONCLUSIONS
Our study revealed for the first time that MTc both in UA and in UV depends on modus of labor. In agreement with other studies, we found a clear circadian MT rhythm in the UC blood of neonates. The results of our study may suggest to a physiological role of MT at the onset of labor.
Department of Neonatology, Children's Hospital, University of Bonn, Bonn, Germany. soyhan.bagci@ukb.uni-bonn.de
Soyhan
S
Bagci
Anna Lena
AL
Berner
Jochen
J
Reinsberg
Anne-Sybil
AS
Gast
Berndt
B
Zur
Lars
L
Welzing
Peter
P
Bartmann
Andreas
A
Mueller
D000328:Adult; D002585:Cesarean Section; D002940:Circadian Rhythm; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood*; D008431:Maternal-Fetal Exchange; D008550:Melatonin / Q000032:analysis / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D014469:Umbilical Arteries; D014471:Umbilical Veins
D008550:Melatonin