Pregnancy and cortisol levels

[~MaryO~]

Abstract

 

1: Clin Endocrinol (Oxf). 1990 Aug;33(2):279-89.

 

Diurnal salivary cortisol patterns during pregnancy and after delivery: relationship to plasma corticotrophin-releasing-hormone.

 

Allolio B, Hoffmann J, Linton EA, Winkelmann W, Kusche M, Schulte HM.

 

Medizinische Klinik II und Poliklinik, Universitat zu Koln, Universitats Frauenklinik, Koln, FR Germany.

 

The circadian rhythm of salivary cortisol was studied in 10 healthy women every 4 weeks throughout pregnancy. In addition, in 12 women the diurnal patterns of salivary cortisol, serum cortisol, plasma ACTH, plasma CRH and serum progesterone were analysed in late third trimester pregnancy and again 3-5 days after delivery. Salivary cortisol profiles exhibited a clear circadian rhythm during pregnancy with an increase in mean salivary cortisol from the 25th to 28th week onwards reaching concentrations in late pregnancy more than twice as high as in non-pregnant controls, rapidly returning to normal concentrations after delivery. The coefficient of variation of salivary cortisol profiles decreased in third trimester pregnancy due to a parallel upward shift of cortisol concentrations (40.2 +/- 3.4% vs 77.6 +/- 6.6% after delivery, P less than 0.01). A diurnal pattern was also found for plasma ACTH and serum cortisol before and after delivery with lower concentrations post-partum (P less than 0.01). In late pregnancy, progesterone concentrations were significantly higher in the evening (930 +/- 85 nmol/l vs 813 +/- 74 nmol/l at 0900 h, P less than 0.01) but showed no diurnal variation post-partum. Plasma CRH was significantly elevated in late third trimester pregnancy (1.22 +/- 0.23 micrograms/l at 0900 h) but showed no diurnal change (1.30 +/- 0.28 micrograms/l at 1900 h). Moreover, no correlation between the free cortisol increase in late pregnancy and plasma CRH was noted despite a wide range of CRH levels (0.13-3.60 micrograms/l). In contrast, a significant correlation was observed between the serum progesterone increase and the salivary cortisol increase in late pregnancy (r = 0.70, P less than 0.05). These findings demonstrate that placental CRH is not the only regulator of maternal ACTH and cortisol release. Instead, our study suggests that placental CRH has little influence on baseline maternal adrenocortical function in pregnancy. The elevated salivary cortisol levels in pregnancy may be explained by glucocorticoid resistance owing to the antiglucocorticoid action of high progesterone concentrations.

 

PMID: 2225483 [PubMed - indexed for MEDLINE]

 

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Abstract

 

Am J Obstet Gynecol. 1981 Feb 15;139(4):416-22.  Related Articles, Links  

 

Maternal plasma adrenocorticotropin and cortisol relationships throughout human pregnancy.

 

Carr BR, Parker CR Jr, Madden JD, MacDonald PC, Porter JC.

 

Adrenocorticotropin (ACTH) and cortisol in plasma were measured weekly from early in gestation through delivery in five women whose pregnancies were normal. During the twelfth week of pregnancy, the concentration of ACTH in plasma of blood samples obtained between 0800 and 0900 hours was 23 +/- 4.6 pg/ml (mean and SEM) and rose progressively to 59 +/- 16 pg/ml at 37 weeks. The levels of ACTH in plasma were significantly lower throughout pregnancy than those found in nonpregnant women. During labor and delivery, ACTH levels rose strikingly to values of 301 +/- 137 pg/ml. As pregnancy advanced, the concentration of cortisol in plasma increased progressively from 149 +/- 34 ng/ml (mean and SEM) at 12 weeks to 352 +/- 90 ng/ml at 26 weeks' gestation but changed minimally thereafter until labor commenced, during which values of 706 +/- 148 ng/ml were achieved. ACTH and cortisol secretory patterns over a 24-hour period were also investigated in one subject during each trimester of pregnancy. Diurnal variations were observed that were qualitatively similar to those seen in nonpregnant women. From the results of these studies, we conclude that ACTH levels are suppressed in plasma of normal pregnant women but are higher in late pregnancy than in early pregnancy. The rise in plasma ACTH concentrations, as pregnancy advances, in spite of increasing levels of plasma cortisol, estrogens, and progesterone, is suggestive of the possibility that a source of ACTH exists that is not subject to negative feedback control, that the clearance of free cortisol increases as pregnancy advances, or that there is an alteration in the metabolism of the ACTH precursor protein produced by the pituitary and/or placenta.

 

PMID: 6258436 [PubMed - indexed for MEDLINE]