Norepinephrine, adrenocorticotropin, cortisol and beta-endorphin in women suffering from fear of labor: responses to the cold pressor test during and after pregnancy.
BACKGROUND
Women suffering from fear of labor have reduced pain tolerance during a cold pressor test (CPT) during and after pregnancy.


METHODS
We compared levels of norepinephrine, adrenocorticotropin (ACTH), cortisol and beta-endorphin before and during the CPT up to 60 min in 20 normotensive women with and 20 without fear of labor at 37.4 +/- 0.2 (mean +/- SE) gestational weeks and at 41.9 +/- 1.6 weeks after delivery.


RESULTS
Baseline levels of norepinephrine in the pregnant fear group (1.63 +/- 0.18 nmol/L) were higher (p = 0.068) than in controls (1.38 +/- 0.14 nmol/L) but after delivery they were lower in the fear group (1.75 +/- 0.31 nmol/L vs. 2.31 +/- 0.26 nmol/L, p = 0.064). ACTH, cortisol and beta-endorphin did not differ between pregnant and nonpregnant groups. The CPT caused a 28.4% smaller response in norepinephrine in the pregnant fearful women than in controls, whereas the responses of ACTH and beta-endorphin were similar between groups during and after pregnancy. The CPT caused no significant response in cortisol. Pregnant fearful women had higher diastolic blood pressure (85.6 +/- 4.5 mmHg, mean +/- SE) than the controls (74.9 +/- 3.4 mmHg, p = 0.065).


CONCLUSIONS
Women with fear of labor were characterized by changes in norepinephrine but not in ACTH, cortisol or beta-endorphin before and during the CPT, indicating a normal pituitary-adrenal axis function.
Saisto
Terhi
T
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, PO Box 140, Haartmaninkatu 2, FIN-00290 HUS, Helsinki, Finland. terhi.saisto@hus.fi
Kaaja
Risto
R
Helske
Satu
S
Ylikorkala
Olavi
O
Halmesmäki
Erja
E
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D016022:Case-Control Studies; D003080:Cold Temperature; D005239:Fear; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007743:Labor, Obstetric / Q000097:blood* / Q000523:psychology*; D009638:Norepinephrine / Q000097:blood; D017288:Pain Threshold; D049590:Postpartum Period / Q000097:blood*; D011247:Pregnancy / Q000097:blood*; D001615:beta-Endorphin / Q000097:blood
D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D009638:Norepinephrine