Roles of Reproductive Corticotropin-Releasing Hormone

The Value of HPA Axis Hormones as Biomarkers for Screening and Early Diagnosis of Postpartum Depression: Updated Information About Methodology

Because of the high prevalence of postpartum depression (PPD) and the suffering involved, early diagnosis is urgent; however, current screening tools and diagnosis are inadequate. In addition to conventional methods such as the Edinburgh Postnatal Depression Scale and clinical interviews, several hormones in the hypothalamic-pituitary-adrenal (HPA) axis, such as corticotrophin-releasing hormone, adrenocorticotropic hormone, and cortisol, have been considered because of their critical roles in stress regulation in the mothers. The study designs are complicated, however, and so the effectiveness of these hormones as biomarkers for PPD is still controversial. Such inconsistency may have resulted from the variation in methodology between studies. The methodology problems in the investigation of PPD and HPA axis hormones have not been reported extensively. We therefore sought to summarize the methodological problems of studies published in the past decade, including the strengths and weaknesses of the examinations and the technological difficulties involved. Our findings suggest that (a) suitable samples and appropriate detection methods would reduce heterogeneity among trials; (b) the cutoff value of the scale test should be carefully selected for determining the performance of biomarker tests; (c) evaluation methods and criteria should be chosen with consideration of the tools feasible for use in local hospitals and population; and (d) the cost of diagnosis should be reduced. We hope that these findings provide insight for future investigations of HPA axis hormones as biomarkers for screening and early diagnosis of PPD.

Calcium signaling cascades differentially regulate PGF2α-induced myometrial contractions in water buffaloes (Bubalus bubalis)

This study unravels the differential involvement of calcium signaling pathway(s) in PGF_2α-induced contractions in myometrium of nonpregnant (NP) and pregnant buffaloes. Compared to the myometrium of pregnant animals, myometrium of NP buffaloes was more sensitive to PGF_2α as manifested by changes in mean integral tension (MIT) and tonicity. In the presence of nifedipine, myometrial contraction to PGF_2α was significantly attenuated in both NP and pregnant uteri; however, mibefradil and NNC 55-0396 produced inhibitory effects only in uterus of pregnant animals, thus suggesting the role of extracellular Ca²⁺ influx through nifedipine-sensitive L-type Ca²⁺-channels both in NP and pregnant, but T-type Ca²⁺ channels seem to play a role only during pregnancy. Entry of extracellular Ca²⁺ is triggered by enhanced functional involvement of Pyr3-sensitive TRPC3 channels and Rho-kinase pathways as evidenced by a significant rightward shift of the concentration-response curve of PGF_2α in the presence of Pyr3 and Y-27632 in NP myometrium. But significant down-expressions of TRPC3 and Rho-A proteins during pregnancy apparently facilitate uterine quiescence. In the presence of Ca²⁺-free solution and cyclopiazonic acid (SERCA blocker), feeble contraction to PGF_2α was observed in both NP and pregnant myometrium which suggests minor role of intracellular source of Ca²⁺ in mediating PGF_2α-induced contractions in these tissues.

WITHDRAWN: Differential involvement of L- and T-type Ca2+ channels, store-operated calcium channel (TRPC) and Rho-kinase signaling pathway(s) in PGF2α-induced contractions in myometrium of non-pregnant and pregnant buffaloes (Bubalus bubalis)

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Altered functioning of the HPA axis in depressed postpartum women

BACKGROUND

The present study aimed to evaluate the relationship between the functioning of the hypothalamic-pituitary-adrenal (HPA) axis and major depressive episodes in the remote postpartum period.

METHODS

The sample (mean age, 28.0±5.3 years) consisted of 37 depressed postpartum women (DPP), 42 euthymic postpartum women (EPP) and 25 non-postpartum healthy women (HC). Salivary cortisol samples were collected immediately after awakening and 30min, 3 and 12h later, at approximately the sixth month postpartum (mean, 169.6±60.3 days).

RESULTS

Differences in cortisol levels were observed at awakening (DPP<EPP=HC), at 30min (DPP<EPP<HC), at 3h (DPP=EPP<HC) and at 12h (DPP>EPP=HC). The relative increment in the cortisol awakening response (CARi%) was significantly higher in HC (113.5±94.3) than in EPP (63.1±69.8) and DPP (32.2±49.6). The relative reduction in diurnal variation (DVr%) was lower in DPP (56.5±41.8) than in EPP (75.6±22.4) and HC (75.1±13.0).

LIMITATIONS

The main limitation was cortisol collection on a single day and without measurement at midnight.

CONCLUSIONS

Our findings suggest that the remote postpartum period involves attenuation of HPA axis reactivity; this dysregulation is more pronounced in the presence of DPP, which is associated with a reduction in cortisol diurnal variation. Abnormalities in the neuroendocrine system related to stress processing, present even several months after delivery, can represent vulnerability to mental disorders. Thus, improvements in the mental health care of postpartum women are needed.

Activation and regulation of endogenous retroviral genes in the human pituitary gland and related endocrine tumours

AIMS

Adenohypophysis (AH) hormone-producing cells represent the origin of diverse groups of pituitary adenomas (PA). Deregulation of hypothalamic hormone receptors, growth factors and cAMP signalling have been implicated in the aetiology of PA. Endogenous retroviruses (ERVs) are derived from past exogenous retroviral infections and represent more than 8% of the human genome. Some ERV genes encode open reading frames and produce functional proteins, for example, the ERVW-1 envelope gene Syncytin-1, essential for placentogenesis, but also deregulated in human tumours. Data concerning ERV expression in the AH and related endocrine tumours are missing.

METHODS

Syncytin-1 protein was analysed in normal AH (n = 15) and compared with five PA subtypes (n = 117) by immunohistochemistry. Absolute gene expression of 20 ERV functional envelope genes and ERVW-5 gag was measured. PA tissues were examined for Syncytin-1 and the cAMP signalling marker phospho-CREB-Ser133 using immunohistochemistry. Isolated primary human PA cells were treated with different hormones. Murine embryonic and adult pituitary gland ERV expressions were compared with human AH.

RESULTS

Syncytin-1 protein colocalized with corticotropic cells of AH. In contrast, all PA demonstrated significant Syncytin-1 protein overexpression, supporting deregulation. All other ERV genes showed significant up-regulations in different PA subtypes. Phospho-CREB-Ser133 and Syncytin-1 colocalized in PA cells. Cultivated primary PA cells with ACTH or CRH induced their respective receptors and ERV genes. Syncytin-A/-B, murine orthologues to human Syncytin-1/-2, localized to embryonic and adult pituitary glands demonstrating functional mammalian conservation.

CONCLUSIONS

Deregulated ERV genes may contribute to PA development via cAMP signalling.

Social Crowding during Development Causes Changes in GnRH1 DNA Methylation

Gestational and developmental cues have important consequences for long-term health, behavior and adaptation to the environment. In addition, social stressors cause plastic molecular changes in the brain that underlie unique behavioral phenotypes that also modulate fitness. In the adult African cichlid, Astatotilapia burtoni, growth and social status of males are both directly regulated by social interactions in a dynamic social environment, which causes a suite of plastic changes in circuits, cells and gene transcription in the brain. We hypothesized that a possible mechanism underlying some molecular changes might be DNA methylation, a reversible modification made to cytosine nucleotides that is known to regulate gene function. Here we asked whether changes in DNA methylation of the GnRH1 gene, the central regulator of the reproductive axis, were altered during development of A. burtoni. We measured changes in methylation state of the GnRH1 gene during normal development and following the gestational and developmental stress of social crowding. We found differential DNA methylation within developing juveniles between 14-, 28- and 42-day-old. Following gestational crowding of mouth brooding mothers, we saw differential methylation and transcription of GnRH1 in their offspring. Taken together, our data provides evidence for social control of GnRH1 developmental responses to gestational cues through DNA methylation.

Reproductive outcomes associated with noise exposure - a systematic review of the literature

Introduction: High noise exposure during critical periods in gestation is a potential stressor that may result in increased risk of implantation failure, dysregulation of placentation or decrease of uterine blood flow. This paper systematically reviews published evidence on associations between reproductive outcomes and occupational and environmental noise exposure. Methods: The Web of Science, PubMed and Embase electronic databases were searched for papers published between 1970 to June 2014 and via colleagues. We included 14 epidemiological studies related to occupational noise exposure and nine epidemiological studies related to environmental noise exposure. There was some evidence for associations between occupational noise exposure and low birthweight, preterm birth and small for gestational age, either independently or together with other occupational risk factors. Five of six epidemiologic studies, including the two largest studies, found significant associations between lower birthweight and higher noise exposure. There were few studies on other outcomes and study design issues may have led to bias in assessments in some studies. Conclusions: There is evidence for associations between noise exposure and adverse reproductive outcomes from animal studies. Few studies in have been conducted in humans but there is some suggestive evidence of adverse associations with environmental noise from both occupational and epidemiological studies, especially for low birthweight.

Prereproductive stress to female rats alters corticotropin releasing factor type 1 expression in ova and behavior and brain corticotropin releasing factor type 1 expression in offspring

BACKGROUND

Human and animal studies indicate that vulnerability to stress may be heritable and that changes in germline may mediate some transgenerational effects. Corticotropin releasing factor type 1 (CRF1) is a key component in the stress response. We investigated changes in CRF1 expression in brain and ova of stressed female rats and in the brain of their neonate and adult offspring. Behavioral changes in adulthood were also assessed.

METHODS

Adult female rats underwent chronic unpredictable stress. We extracted mature oocytes and brain regions from a subset of rats and mated the rest 2 weeks following the stress procedure. CRF1 expression was assessed using quantitative reverse-transcription polymerase chain reaction. Tests of anxiety and aversive learning were used to examine behavior of offspring in adulthood.

RESULTS

We show that chronic unpredictable stress leads to an increase in CRF1 messenger RNA expression in frontal cortex and mature oocytes. Neonatal offspring of stressed female rats show an increase in brain CRF1 expression. In adulthood, offspring of stressed female rats show sex differences in both CRF1 messenger RNA expression and behavior. Moreover, CRF1 expression patterns in frontal cortex of female offspring depend upon both maternal and individual adverse experience.

CONCLUSIONS

Our findings demonstrate that stress affects CRF1 expression in brain but also in ova, pointing to a possible mechanism of transgenerational transmission. In offspring, stress-induced changes are evident at birth and are thus unlikely to result from altered maternal nurturance. Finally, brain CRF1 expression in offspring depends upon gender and upon maternal and individual exposure to adverse environment.

Adrenal insufficiency in pregnancy: challenging issues in diagnosis and management

Adrenal insufficiency (AI) in pregnancy is relatively rare, but it is associated with significant maternal and fetal morbidity and mortality if untreated during gestation or in the puerperium. Hence, timely diagnosis and decisive treatment by the clinician are critical. However, due to pregnancy-induced metabolic and endocrine changes and the resemblance of symptomatology of AI to those of pregnancy, the diagnosis is often difficult to recognize and challenging to confirm. Normal pregnancy is a state of glucocorticoid excess particularly in the latter stages, and normative values for serum cortisol levels are not well-established. Furthermore, testing the hypothalamic-pituitary-adrenal axis using validated stimulation tests during pregnancy are lacking. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge, focussing on the challenges in recognizing AI in pregnancy and interpreting the diagnostic tests, and to propose a clinical approach for optimizing the management of AI in women diagnosed before or during pregnancy.

Combined quantification of corticotropin-releasing hormone, cortisol-to-cortisone ratio and progesterone by liquid chromatography-Tandem mass spectrometry in placental tissue

With mid-gestation the production of placental corticotropin-releasing hormone (CRH) starts to steadily increase. The fetal peptide CRH excerts direct functions at the feto-maternal interface (vasodilatation, timing of birth) via its interaction with progesterone and indirectly ensures maturation and growth of fetal organ systems for delivery by driving fetal cortisol production via its induction of adrenocorticotropic hormone release. This feedback loop is tightly controlled by the amount of enzymatic cortisol/cortisone turnover in the placental syncytiotrophoblast by 11β-hydroxy-steroid dehydrogenase type 2 (11β-HSD2). Traditionally, placental tissue hormones have been quantified by immunological methods (e.g. RIA or ELISA), which have the drawback of possible cross-reactivity and tissue perturbations. Most importantly, it is not possible to quantify CRH and steroid hormones, such as cortisol, cortisone and progesterone together in the same sample with these methods. Hence, we aimed to develop and validate a quantitative mass spectrometry (MS) method for multi-modal quantification of these placental hormones: While CRH was readily detectable throughout the placenta, the placental levels of progesterone and especially cortisol and cortisone were higher at the placental base facing the maternal side. The HPLC-MS/MS procedure showed excellent selectivity and sufficient limit of quantification in placental tissue homogenates to allow for simultaneous detection of CRH, cortisol and cortisone, and progesterone.

Corticotropin-releasing hormone stimulates expression of leptin, 11beta-HSD2 and syncytin-1 in primary human trophoblasts

BACKGROUND

The placental syncytiotrophoblast is the major source of maternal plasma corticotropin-releasing hormone (CRH) in the second half of pregnancy. Placental CRH exerts multiple functions in the maternal organism: It induces the adrenal secretion of cortisol via the stimulation of adrenocorticotropic hormone, regulates the timing of birth via its actions in the myometrium and inhibits the invasion of extravillous trophoblast cells in vitro. However, the auto- and paracrine actions of CRH on the syncytiotrophoblast itself are unknown. Intrauterine growth restriction (IUGR) is accompanied by an increase in placental CRH, which could be of pathophysiological relevance for the dysregulation in syncytialisation seen in IUGR placentas.

METHODS

We aimed to determine the effect of CRH on isolated primary trophoblastic cells in vitro. After CRH stimulation the trophoblast syncytialisation rate was monitored via syncytin-1 gene expression and beta-hCG (beta-human chorionic gonadotropine) ELISA in culture supernatant. The expression of the IUGR marker genes leptin and 11beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2) was measured continuously over a period of 72 h. We hypothesized that CRH might attenuate syncytialisation, induce leptin, and reduce 11beta-HSD2 expression in primary villous trophoblasts, which are known features of IUGR.

RESULTS

CRH did not influence the differentiation of isolated trophoblasts into functional syncytium as determined by beta-hCG secretion, albeit inducing syncytin-1 expression. Following syncytialisation, CRH treatment significantly increased leptin and 11beta-HSD2 expression, as well as leptin secretion into culture supernatant after 48 h.

CONCLUSION

The relevance of CRH for placental physiology is underlined by the present in vitro study. The induction of leptin and 11beta-HSD2 in the syncytiotrophoblast by CRH might promote fetal nutrient supply and placental corticosteroid metabolism in the phase before labour induction.

Aberrant expression of corticotropin-releasing hormone in pre-eclampsia induces expression of FasL in maternal macrophages and extravillous trophoblast apoptosis

Corticotropin-releasing hormone (CRH) and its receptors are expressed in human placenta. Recently, the impaired function of this system has been associated with a number of complications of pregnancy, including pre-eclampsia. The aim of the study was to test the hypothesis that CRH participates in the pathophysiology of pre-eclampsia through the induction of macrophage-mediated apoptosis of extravillous trophoblasts (EVTs). We found that the expression of CRH was increased in the EVT of the placental bed biopsy specimens from pre-eclamptic pregnancies (1.8-fold increase; P < 0.05). In addition, significantly larger numbers of apoptotic EVT were detected in pre-eclamptic placentas compared with normal ones (P < 0.05), and only in pre-eclamptic placentas, decidual macrophages were found to be Fas ligand (FasL)-positive. In vitro studies on the effect of CRH on human macrophages suggested that CRH induced the expression of the FasL protein in human macrophages and potentiated their ability to induce the apoptosis of a Fas-expressing EVT-based hybridoma cell line in co-cultures. These findings demonstrate a possible mechanism by which the aberrant expression of CRH in pre-eclampsia may activate the FasL-positive decidual macrophages, impair the physiological turnover of EVT and eventually disturb placentation.

Expression of CRH, CRH-related peptide and CRH receptor in the ovary and potential CRH signalling pathways

Capacity to cope with stress is crucial for survival and also reproduction. The stress response differs in the various parts of an organism. Central corticotropin-releasing hormone (CRH) has been identified to be the main stress regulator. In the reproductive system, stress has a deleterious effect on reproduction and CRH is associated with dysfunction of the reproductive endocrine axis. Members of the CRH family have been detected in different reproductive organs of males and females. Ovarian CRH is probably involved in steroid biosynthesis and inflammatory like processes, ovulation and luteolysis. These effects are mediated via the CRH receptors CRH-R1 and CRH-R2. CRH-Rs are G protein-coupled receptors that drive different signalling pathways in the cell. In human, ligands for these receptors are CRH, urocortin 1, stresscopin-related peptide and stresscopin. This review gives an overview on the expression of the CRH family members in the ovary of mammals. Furthermore, potential CRH-induced signalling mechanisms in the ovary will be introduced.

Cushing's syndrome in pregnancy: an overview

Cushing's syndrome (CS) during pregnancy is a rare condition with fewer than 150 cases reported in the literature. Adrenal adenomas were found to be the commonest cause, followed by Cushing's disease. The gestation dramatically affects the maternal hypothalamic-pituitary-adrenal axis, resulting in increased hepatic production of corticosteroid-binding globulin (CBG), increased levels of serum, salivary and urinary free cortisol, lack of suppression of cortisol levels after dexamethasone administration and placental production of CRH and ACTH. Moreover, a blunted response of ACTH and cortisol to exogenous CRH may also occur. Therefore, the diagnosis of CS during pregnancy is much more difficult. Misdiagnosis of CS is also common, as the syndrome may be easily confused with preeclampsia or gestational diabetes. Because CS during pregnancy is usually associated with severe maternal and fetal complications, its early diagnosis and treatment are critical. Surgery is the treatment of choice for CS in pregnancy, except perhaps in the late third trimester, with medical therapy being a second choice. There does not seem to be a rationale for supportive treatment alone.

Stress and reproductive failure: past notions, present insights and future directions

PROBLEM

Maternal stress perception is frequently alleged as a cause of infertility, miscarriages, late pregnancy complications or impaired fetal development. The purpose of the present review is to critically assess the biological and epidemiological evidence that considers the plausibility of a stress link to human reproductive failure.

METHODS

All epidemiological studies published between 1980 and 2007 that tested the link between stress exposure and impaired reproductive success in humans were identified. Study outcomes were evaluated on the basis of how associations were predicted, tested and integrated with theories of etiology arising from recent scientific developments in the basic sciences. Further, published evidence arising from basic science research has been assessed in order to provide a mechanistic concept and biological evidence for the link between stress perception and reproductive success.

RESULTS

Biological evidence points to an immune-endocrine disequilibrium in response to stress and describes a hierarchy of biological mediators involved in a stress trigger to reproductive failure. Epidemiological evidence presents positive correlations between various pregnancy failure outcomes with pre-conception negative life events and elevated daily urinary cortisol. Strikingly, a relatively new conceptual approach integrating the two strands of evidence suggests the programming of stress susceptibility in mother and fetus via a so-called pregnancy stress syndrome.

CONCLUSIONS

An increasing specificity of knowledge is available about the types and impact of biological and social pathways involved in maternal stress responses. The present evidence is sufficient to warrant a reconsideration of conventional views on the etiology of reproductive failure. Physicians and patients will benefit from the adaptation of this integrated evidence to daily clinical practice.

"Reproductive" corticotropin-releasing hormone

Corticotropin-releasing hormone (CRH), a 41 amino acid peptide, is an important regulatory molecule synthesized by neurons of the parvocellular and magnocellular hypothalamic paraventricular nuclei. It acts as the major physiologic corticotropin (ACTH) secretagogue. The CRH gene is located in humans on chromosome 8. The CRH hormone family has at least four ligands, two receptors (CRH-R1 and CRH-R2), and a binding protein (CRHbp). CRH is the principal regulator of the hypothalamic-pituitary-adrenal axis. Furthermore, CRH has been identified in most female reproductive tissues including the uterus, the placenta, and the ovary. CRH produced in the endometrium may participate in decidualization, implantation, and early maternal tolerance to semiallograft embryo. Placental CRH may participate in the physiology of pregnancy, in late pregnancy complications such as preterm labor and preeclampsia, and also in the onset of parturition. Ovarian CRH is involved in follicular maturation, ovulation, and luteolysis. Increased levels of unbound placental CRH may be responsible for the hypercortisolism of the second half of pregnancy. This hypercortisolism is followed by a transient suppression of hypothalamic CRH secretion in the postpartum period. This may explain the depressive states frequently observed in the postpartum period.

Mechanisms of implantation

Successful embryo implantation in mammals requires the co-ordinated development of a blastocyst competent to implant and an adhesive endometrium. Given the indispensable role of implantation for the furtherance of the species, a number of molecular mechanisms have evolved to regulate the process. A variety of molecules, produced by embryo as well as maternal tissue participates in the cross-talk between the implanting blastocyst and the endometrium. The interplay between the various molecules and the routes in which they are involved is beginning to be elucidated. Because impaired implantation represents the most important limiting factor in the establishment of pregnancy, it is believed that research in the field will allow clinicians to improve the respective rates. This paper reviews certain groups of molecules that are considered to have key roles in the mechanisms of implantation.

Assessment of adrenal reserve in pregnancy: defining the normal response to the adrenocorticotropin stimulation test

CONTEXT

Normal pregnancy is a state of hypercortisolism, making adrenal insufficiency difficult to diagnose.

OBJECTIVE

We sought to identify a normative, minimum-response threshold for the ACTH stimulation test in pregnancy. We hypothesized that salivary free cortisol (SaFC) would prove a more physiological and less variable measure of adrenal reserve in pregnancy than serum cortisol (SC).

DESIGN

This is a prospective study of normal controls.

SETTING

The study was conducted in an obstetrical clinic in a tertiary care hospital.

PATIENTS

Patients included 36 healthy ambulatory pregnant women (aged 18-37 yr) with singleton pregnancies.

INTERVENTION

The 250-microg ACTH stimulation test was performed in the healthy pregnant volunteers. Based on their gestational age at the time of recruitment, women were studied in one of the trimesters and were restudied at 11-14 wk postpartum.

MAIN OUTCOME MEASURES

Total SC, aldosterone, and SaFC concentrations were measured before and after ACTH. The response in pregnancy was compared with postpartum values.

RESULTS

Basal SC (P = 0.01), aldosterone (P = 0.001), and SaFC (P = 0.01) values progressively increased during the trimesters of pregnancy and decreased postpartum, confirming that pregnant women have increased basal glucocorticoid and mineralocorticoid production. There was enhanced responsiveness of the maternal adrenal glands to ACTH stimulation as pregnancy progressed, as measured by peak stimulated SaFC (P = 0.009) and aldosterone (P = 0.01). In the milieu of altered binding globulins, SaFC is a more consistent, binding-globulin-independent measure of stimulated adrenal function than total SC. Minimum criteria for the normal SaFC response to ACTH stimulation in the second and third trimesters of pregnancy and postpartum have been generated based on a predominantly African-American group of subjects.

CONCLUSIONS

Reliable data are available for the evaluation of the adrenal axis in pregnancy with a noninvasive, outpatient measure of SaFC. Glucocorticoid therapy in pregnancy should take into account that adrenal reserve increases as pregnancy progresses.

The HPA axis and perinatal depression: a hypothesis

Episodes of depression and anxiety are as common during pregnancy as postpartum. Some start in pregnancy and resolve postpartum, others are triggered by parturition and some are maintained throughout. In order to determine any biological basis it is important to delineate these different subtypes. During pregnancy, as well as the rise in plasma oestrogen and progesterone there is a very large increase in plasma corticotropin releasing hormone (CRH), and an increase in cortisol. The latter reaches levels found in Cushing's syndrome and major melancholic depression. Levels of all these hormones drop rapidly on parturition.We here suggest that the symptoms of antenatal and postnatal depression may be different, and linked in part with differences in the function of the hypothalamic pituitary adrenal (HPA) axis. There are two subtypes of major depression, melancholic and atypical, with some differences in symptom profile, and these subtypes are associated with opposite changes in the HPA axis. Antenatal depression may be more melancholic and associated with the raised cortisol of pregnancy, whereas postnatal depression may be more atypical, triggered by cortisol withdrawal and associated with reduced cortisol levels. There is evidence that after delivery some women experience mild bipolar II depression, and others experience post traumatic stress disorder. Both of these are associated with atypical depression. It may also be that some women are genetically predisposed to depression of the melancholic type and some to depression of the atypical type. These women may be more or less vulnerable to depression at the different stages of the perinatal period.

The hypothalamic-pituitary-adrenal axis in pregnancy: challenges in disease detection and treatment

Pregnancy dramatically affects the hypothalamic-pituitary-adrenal axis leading to increased circulating cortisol and ACTH levels during gestation, reaching values in the range seen in Cushing's syndrome (CS). The cause(s) of increased ACTH may include placental synthesis and release of biologically active CRH and ACTH, pituitary desensitization to cortisol feedback, or enhanced pituitary responses to corticotropin-releasing factors. In this context, challenges in diagnosis and management of disorders of the hypothalamic-pituitary-adrenal axis in pregnancy are discussed. CS in pregnancy is uncommon and is associated with fetal morbidity and mortality. The diagnosis may be missed because of overlapping clinical and biochemical features in pregnancy. The proportion of patients with primary adrenal causes of CS is increased in pregnancy. CRH stimulation testing and inferior petrosal sinus sampling can identify patients with Cushing's disease. Surgery is a safe option for treatment in the second trimester; otherwise medical therapy may be used. Women with known adrenal insufficiency that is appropriately treated can expect to have uneventful pregnancies. Whereas a fetal/placental source of cortisol may mitigate crisis during gestation, unrecognized adrenal insufficiency may lead to maternal or fetal demise either during gestation or in the puerperium. Appropriate treatment and management of labor are reviewed.