High copeptin concentrations in umbilical cord blood after vaginal delivery and birth acidosis.
BACKGROUND
The pituitary-secreted nonapeptide arginine-vasopressin (AVP) is unstable and therefore unsuited for diagnostic use, but its secretion can be estimated by measuring copeptin, the C-terminal portion of the AVP precursor (pro-AVP).


OBJECTIVE
Our objective was to investigate perinatal factors affecting copeptin concentrations in infants at birth and at 3 d of life.


METHODS
We conducted a prospective cross-sectional study at a tertiary university hospital.


METHODS
Copeptin plasma concentrations were evaluated in 177 infants at birth, including 117 paired arterial/venous umbilical cord and 102 venous blood samples obtained at 3 d of life.


METHODS
Copeptin concentrations were determined by a C-terminal pro-AVP luminescence immunoassay.


RESULTS
Arterial umbilical cord copeptin concentrations were consistently higher than matched venous ones (median 18 vs. 10 pmol/liter, P < 0.001), but both values were closely related (R(s) = 0.825; P < 0.001), and both were negatively related to arterial umbilical cord pH (R(s) arterial/venous = -0.578/-0.639; P < 0.001). Although exceedingly high copeptin concentrations were observed after vaginal birth in umbilical cord arterial [median (5-95% range) = 1610 (85-5000) pmol/liter] and venous [793 (6-4836) pmol/liter] plasma, copeptin concentrations were low after primary cesarean section [arterial/venous = 8 (3-907)/5 (5-504) pmol/liter]. Postnatal body weight loss was associated with increased copeptin concentrations at d 3 (R(s) = 0.438; P < 0.001) and was inversely related to copeptin concentrations at birth (R(s) = -0.289 and -0.309; both P = 0.001).


CONCLUSIONS
Vaginal birth is associated with a large release of copeptin that exceeds all values published so far, including those in critically ill adult patients with shock or brain injury. Thus, vaginal birth is arguably the most intense stressor in life.
Wellmann
Sven
S
Department of Neonatology, University Hospital Zurich, Zurich, Switzerland. sven.wellmann@usz.ch
Benzing
Jörg
J
Cippà
Giuditta
G
Admaty
Deborah
D
Creutzfeldt
Ruth
R
Mieth
Romaine Arlettaz
RA
Beinder
Ernst
E
Lapaire
Olav
O
Morgenthaler
Nils G
NG
Haagen
Ulrike
U
Szinnai
Gabor
G
Bührer
Christoph
C
Bucher
Hans Ulrich
HU
D001127:Arginine Vasopressin / Q000097:blood*; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006020:Glycopeptides / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D018709:Statistics, Nonparametric
D006020:Glycopeptides; C048197:copeptins; D001127:Arginine Vasopressin