Glucocorticoid Metabolism in Pregnancy and Fetal Development

Glucocorticoids are essential steroid hormones that orchestrate maternal adaptation to pregnancy and drive organ maturation of the fetus. In the placenta, a finely tuned metabolic barrier—centred on the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2)—converts active cortisol to inactive cortisone, thereby protecting the developing fetus from excessive glucocorticoid exposure. A complementary enzyme, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), regenerates cortisol in target tissues and may contribute to local regulation of growth and differentiation. Further control is provided by 5α- and 5β-reductases, which inactivate both cortisol and cortisone to tetrahydro metabolites. Together, these pathways shape fetal hypothalamic–pituitary–adrenal axis programming, influence birth weight, and set trajectories for lifelong metabolic and cardiovascular health.

Throughout gestation, placental syncytiotrophoblasts undergo dynamic changes in enzyme expression, epigenetic regulation and responsiveness to maternal hormones. Disruption of this balance contributes to hypertensive disorders, pre-eclampsia and foetal growth restriction. Clinical assays of cortisol-to-cortisone ratios in plasma or urine now offer non-invasive insight into placental enzyme function. Understanding the interplay between maternal stress, placental barrier integrity and foetal demand supports the development of biomarkers and targeted interventions aimed at reducing perinatal morbidity and long-term disease risk.

Research from Nature Portfolio

Recent analysis of pregnancies yielding small-for-gestational-age neonates has revealed that systemic cortisol metabolism is most intensive when foetal growth restriction occurs in conjunction with pre-eclampsia. Enhanced activity of placental 11β-HSD2 and increased clearance by 5α- and 5β-reductases were observed, with notable sex-specific differences in enzyme function. These findings underline the complexity of foetal sex in modulating glucocorticoid handling and point to metabolic profiling as a promising tool for early identification of at-risk pregnancies.

Glucocorticoid Metabolism in Pregnancy and Fetal Development publication trend

The graph below shows the total number of articles in glucocorticoid metabolism in pregnancy and fetal development across all publications each year (not limited to Nature Index journals).

Technical terms

Glucocorticoids: Steroid hormones secreted by the adrenal cortex that regulate metabolism, immune function and stress responses.

11β-HSD2: Placental enzyme that converts active cortisol into inactive cortisone, forming a barrier to maternal glucocorticoids.

11β-HSD1: Enzyme that regenerates cortisol from cortisone in peripheral tissues, modulating local glucocorticoid action.

5α- and 5β-reductases: Enzymes that irreversibly inactivate cortisol and cortisone to tetrahydro and allo-tetrahydro metabolites.

Cortisol-to-cortisone ratio: Biochemical measure of the balance between active and inactive glucocorticoids, reflecting enzyme activity.

Syncytiotrophoblast: Multinucleated placental cell layer that mediates nutrient and hormone exchange between mother and fetus.

References

1. TFEB controls syncytiotrophoblast formation and hormone production in placenta. Cell Death & Differentiation (2024).
2. Role of EZH2-mediated H3K27me3 in placental ADAM12-S expression: implications for fetoplacental growth. BMC Medicine (2022).
3. Glucocorticoid Metabolism in Hypertensive Disorders of Pregnancy: Analysis of Plasma and Urinary Cortisol and Cortisone. PLOS ONE (2015).
4. Cortisol metabolism in pregnancies with small for gestational age neonates. Scientific Reports (2019).
5. A Lower Maternal Cortisol-to-Cortisone Ratio Precedes Clinical Diagnosis of Preterm and Term Preeclampsia by Many Weeks. The Journal of Clinical Endocrinology & Metabolism (2019).
6. Increased cortisol metabolism in women with pregnancy-related hypertension. Endocrine (2018).