Postdate pregnancy: Changes of placental/membranes 11β-hydroxysteroid dehydrogenase mRNA and activity

11β-hydroxysteroid dehydrogenase type 1 and pregnancy: Role in the timing of labour onset and in myometrial contraction

Glucocorticoids play a primary role in the maturation of fetal organs and may contribute to the onset of labour. Glucocorticoid activity depends on the 11β-hydroxysteroid dehydrogenase family (11β-HSDs), catalysing the interconversion between "active" cortisol into inactive cortisone. No definitive study exists on 11β-HSD expression profile in human decidua and myometrium during pregnancy. We investigated the implications of 11β-HSD1 in the regulation of uterine activity in pregnancy, examining its role on contraction of a myocyte cell line and murine 11β-hsd1 levels in utero. Murine 11β-hsd1 mRNA and protein levels in utero progressively increased until the last day of gestation and significantly decreased at the onset of labour (P < 0.0001) (n = 3 to 5 in the various gestational days analysed). Experiments on human myometrial samples confirm the significant fall in 11β-hsd1 mRNA levels at labour, compared to end pregnancy samples (n = 5 to 8). In vitro experiments showed that human myometrial contraction is inhibited by using a non-selective inhibitor of 11β-HSD1. The present study shows the temporal localisation of 11β-HSD1 in uterus, highlighting its importance in the timing of gestation and suggesting its contribution in the myometrium contraction.

Tandem mass spectrometry determined maternal cortisone to cortisol ratio and psychiatric morbidity during pregnancy-interaction with birth weight

Maternal serum cortisol has been suggested to be influenced by psychiatric morbidity, and may also influence fetal growth. However, several studies found equal cortisol levels in depressed and healthy pregnant women. Placental 11-β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) shields the fetus from maternal cortisol by conversion to cortisone, a function that may be compromised by maternal stress. We aimed to compare the serum ratio of cortisone to cortisol, in women with and without psychiatric morbidity during pregnancy. A secondary aim was to investigate whether fetal growth, approximated by infant birth weight, was associated with the cortisone to cortisol ratio. We performed tandem mass spectrometry analysis of serum cortisol and cortisone in late pregnancy in 94 women with antenatal psychiatric morbidity and 122 controls (cohort 1). We also compared the placental gene expression of HSD11B1 and 2 in another group of 69 women with psychiatric morbidity and 47 controls (cohort 2). There were no group differences in cortisol to cortisone ratio, absolute levels of cortisone and cortisol (cohort 1), or expression of HSD11B1 or 2 (cohort 2). However, cortisone to cortisol ratio was positively associated with birth weight in women with psychiatric morbidity, also after adjustment for gestational length, fetal sex, maternal height, smoking, SSRI use, and time of blood sampling (standardized β=0.35, p<0.001), with no association in the healthy controls Thus, the maternal serum cortisone to cortisol ratio does not seem to be affected by psychiatric morbidity, but psychiatric morbidity may increase fetal exposure to cortisol or other metabolic factors influencing fetal growth.

Cortisol during human fetal life: Characterization of a method for processing small quantities of newborn hair from 26 to 42 weeks gestation

OBJECTIVE

Fetal cortisol may be reflected in hair collected shortly after birth. The objective of this study was to determine the range of human fetal hair cortisol concentrations (HCC) in live-born neonates using an approach for processing small quantities of hair.

MATERIALS AND METHODS

Hair was cut on the day of birth from neonates and their mothers, born between 26 and 42 weeks gestational age (GA). HCC was determined by enzyme immunoassay. Maternal sociodemographics and birth data were collected. T-tests, ANOVA, Pearson correlation, and Wilcoxon Signed Rank test were used as appropriate.

RESULTS

Ninety maternal and neonatal hair samples were cut from 79 term (T) and 11 preterm (PT) delivered pregnancies. All samples weighed ≥2.5 mg. Fetal HCC correlated with GA (r = .25, p = .02) and birth weight (r = .25, p = .03) and was lower in PT (4.3 ± .3 LN pg/mg) than T (5.3 ± .1, LN pg/mg, p < .001) neonates. No significant relationships were seen between fetal HCC and maternal characteristics or maternal HCC. Fetal HCC was significantly higher than maternal HCC.

CONCLUSION

Fetal cortisol exposure was determined using this approach for processing small amounts of hair. Preterm neonates have significantly lower HCC than term neonates and fetal HCC is associated with GA at delivery and birth weight. Fetal HCC is significantly higher than maternal HCC cut on the same day. These data provide novel information on the intrauterine fetal cortisol environment.