Use of corticosteroids by Australian obstetricians--a survey of clinical practice

Low H3K27 acetylation of SF1 in PBMC: a biomarker for prenatal dexamethasone exposure-caused adrenal insufficiency of steroid synthesis in male offspring

Dexamethasone is widely used to treat pregnancy disorders related to premature delivery. However, lots of researches have confirmed that prenatal dexamethasone exposure (PDE) could increase the risk of offspring multiple diseases. This study was designed to elucidate the epigenetic mechanism of adrenal developmental programming and explore its early warning marker in peripheral blood mononuclear cells (PBMC). We found the adrenal morphological and functional changes of PDE male offspring rats before and after birth, which were mainly performed as the decreased serum corticosterone concentration, steroidogenic acute regulatory (StAR) protein expression, and histone 3 lysine 27 acetylation (H3K27ac) level of steroidogenic factor 1 (SF1) promoter region and its expression. Simultaneously, the expressions of glucocorticoid receptor (GR) and histone acetylation enzyme 5 (HDAC5) in the PDE male fetal rats were increased. In vitro, dexamethasone reduced the expression of SF1, StAR, and cortisol production and still increased the expression of GR and HDAC5, the binding between GR and SF1 promoter region, and protein interaction between GR and HDAC5. GR siRNA or HDAC5 siRNA was able to reverse the above roles of dexamethasone. Furthermore, in vivo, we confirmed that H3K27ac levels of SF1 promoter region and its expression in PBMC of the PDE group were decreased before and after birth, showing a positive correlation with the same indexes in adrenal. Meanwhile, in clinical trials, we confirmed that prenatal dexamethasone application decreased H3K27ac of SF1 promoter region and its expression in neonatal PBMC. In conclusion, PDE-caused adrenal insufficiency of male offspring rats was related to adrenal GR activated by dexamethasone in uterus. The activated GR, on the one hand, increased its direct binding to SF1 promoter region to inhibit its expression, on the other hand, upregulated and recruited HDAC5 to decrease H3K27ac level of SF1 promoter region, and strengthened the inhibition of SF1 and subsequent StAR expression.

MiR-133a-3p/Sirt1 epigenetic programming mediates hypercholesterolemia susceptibility in female offspring induced by prenatal dexamethasone exposure

Mounting evidence indicates that adverse intrauterine conditions increase offspring's hypercholesterolemia susceptibility in adulthood. This study aimed to confirm prenatal dexamethasone exposure (PDE)-induced hypercholesterolemia susceptibility in female adult offspring rats, and elucidate its intrauterine programming mechanism. Pregnant Wistar rats were injected with dexamethasone subcutaneously (0, 0.1 and 0.2 mg/kg·d) from gestational day (GD) 9 to 20. Serum and liver of the female offspring were collected at GD21 and postnatal week (PW) 12 and 28. PDE offspring showed elevated serum total cholesterol (TCH) levels and a cholesterol phenotype of high cardiovascular disease risk at PW12 and PW28. The histone acetylation levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) and its expression were consistently increased in the PDE offspring both in utero and after birth. Moreover, PDE promoted glucocorticoid receptor (GR) nuclear translocation and miR-133a-3p expression and inhibited sirtuin-1 (Sirt1) expression in the fetal liver. In vitro, dexamethasone increased intracellular and supernatant TCH levels and miR-133a-3p expression, decreased SIRT1 expression, and promoted HMGCR histone acetylation and expression in bone marrow mesenchymal stem cells (BMSCs) hepatoid differentiated cells and HepG2 cell line. GR siRNA, miR-133a-3p inhibitor or SIRT1 overexpression reversed dexamethasone-induced downstream molecular and phenotypic changes. Furthermore, elevated TCH levels in umbilical cord blood and increased HMGCR expression in peripheral blood mononuclear cells (PBMCs) were observed in human female neonates who had received dexamethasone treatment during pregnancy. In conclusion, PDE can cause persistent enhancement of hepatic cholesterol synthesis function before and after birth through GR/miR-133a-3p/Sirt1 pathway, eventually leading to increased hypercholesterolemia susceptibility in female offspring rats.

Positive programming of the GC-IGF1 axis mediates adult osteoporosis susceptibility in male offspring rats induced by prenatal dexamethasone exposure

Prenatal dexamethasone exposure (PDE) can lead to offspring long bone dysplasia and continue to postnatal, and this is an important cause of fetal-derived osteoporosis. Studies have confirmed that intrauterine endogenous GC overexposure mediates multiple organ dysplasia and adult-related disease susceptibility in offspring through the glucocorticoid-insulin-like growth factor1 (GC-IGF1) axis. However, it remains unknown if exogenous dexamethasone can regulate bone development in offspring through the GC-IGF1 axis. We determined that the PDE fetal rats exhibited poor osteogenic differentiation, decreased bone mass that continued to adolescence, and increased susceptibility to osteoporosis in adulthood. Concurrently, PDE decreased the serum corticosterone concentration and IGF1 expression in offspring before and after birth, while the increased serum corticosterone concentration induced by chronic stress reversed the inhibition of IGF1 expression induced by PDE. Furthermore, PDE decreased the expression of GRα and miR-130a-5p, increased HDAC4, and decreased H3K27 acetylation in the IGF1 promoter region in bone tissue, and the above changes were negatively compensated after chronic stress. In vitro, a low concentration of corticosterone inhibited the expression of GRα and miR130a-5p, upregulated the expression of HDAC4, inhibited the promoter region H3K27 acetylation, and expression of IGF1 in bone marrow mesenchymal stem cell (BMSCs) osteoblast differentiated cells and inhibited osteogenic differentiation of BMSCs. GRα overexpression, miR-130a-5p mimic treatment, or HDAC4 siRNA exposure reversed the downstream molecular alterations caused by low corticosterone concentrations. In conclusion, PDE-induced intrauterine hypoglucocorticoid exposure could positively program IGF1 expression in bone tissue through the GRα/miR-130a-5p/HDAC4 pathways, thus mediating osteogenic dysdifferentiation and adult osteoporosis susceptibility in male offspring rats.

Sex difference in adrenal developmental toxicity induced by dexamethasone and its intrauterine programming mechanism

Dexamethasone is widely used to treat preterm labor and related diseases. However, prenatal dexamethasone treatment (PDT) can cause multiorgan developmental toxicities in offspring. Our previous study found that the occurrence of fetal-originated diseases was associated with adrenal developmental programming alterations in offspring. Here, we investigated the effects of PDT on adrenal function in offspring and its intrauterine programming mechanism. A rat model of PDT was established to observe the alterations of adrenal steroidogenesis in offspring. Furthermore, we confirmed the sex differences of adrenal steroidogenesis and its molecular mechanism combined with in vivo and in vitro experiments. PDT caused a decrease in adrenal steroidogenic function in fetal rats, but it was decreased in males and increased in females after birth. Meanwhile, the adrenal H3K14ac level and expression of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) in PDT offspring were decreased in males and increased in females, suggesting that 11β-HSD2 might mediate sex differences in adrenal function. We further confirmed that dexamethasone inhibited the H3K14ac level and expression of 11β-HSD2 through the GR/SP1/p300 pathway. After bilateral testectomy or ovariectomy of adult PDT offspring rats, adrenal 11β-HSD2 expression and steroidogenic function were both reduced. Using rat primary fetal adrenal cells, the differential expression of AR and ERβ was proven to be involved in regulating the sex difference in 11β-HSD2 expression. This study demonstrated the sex difference in adrenal steroidogenic function of PDT offspring after birth and elucidated a sex hormone receptor-dependent epigenetically regulating mechanism for adrenal 11β-HSD2 programming alteration.

Maternally derived low glucocorticoid mediates adrenal developmental programming alteration in offspring induced by dexamethasone

Adverse environments during pregnancy can increase susceptibility to chronic diseases in adult offspring. The occurrence and development of fetal-originated diseases were associated with adrenal developmental programming and homeostasis alteration in offspring. Dexamethasone is widely used for preterm delivery-related pregnancy diseases, but the intrauterine programming alteration and its occurrence mechanism of prenatal dexamethasone exposure (PDE) on adrenal development in offspring have not been clarified. In this study, prenatal dexamethasone therapy could inhibit neonatal development and cause a low exposure of maternally derived glucocorticoid in clinic. Then, we established a rat model of PDE and observed a similar phenomenon. Further, the adrenal steroidogenic function was continuously inhibited in the PDE male offspring rats, accompanied by the decreased H3K27ac level of adrenal insulin-like growth factor 1 (IGF1) and its expression. Moreover, chronic stress in PDE adult offspring rats could reverse the changes of the above indicators through the high level of glucocorticoid. In combination with in vivo, in vitro and a series of interference experiments, we confirmed that the low level of endogenous glucocorticoids inhibited the adrenal IGF1 expression and steroidogenic function through the GRα/miR-370-3p/Sirt3 pathway. In summary, PDE could continuously inhibit the adrenal steroidogenic function in the male offspring, which is associated with the maternally derived low glucocorticoid-mediated the adrenal developmental programming alteration in offspring. This study provides a theoretical and experimental basis for explaining the adrenal development origin of PDE-induced adult chronic diseases.

Prenatal Glucocorticoid Exposure Modifies Endocrine Function and Behaviour for 3 Generations Following Maternal and Paternal Transmission

Fetal exposure to high levels of glucocorticoids programs long-term changes in the physiologic stress response and behaviours. However, it is not known whether effects manifest in subsequent generations of offspring following maternal (MT) or paternal (PT) transmission. We treated pregnant guinea pigs with three courses of saline or synthetic glucocorticoid (sGC) at a clinically relevant dose. Altered cortisol response to stress and behaviours transmitted to juvenile female and male F2 and F3 offspring from both parental lines. Behavioural effects of sGC in F1-F3 PT females associated with altered expression of genes in the prefrontal cortex and hypothalamic paraventricular nucleus (PVN). Exposure to sGC programmed large transgenerational changes in PVN gene expression, including type II diabetes, thermoregulation, and collagen formation gene networks. We demonstrate transgenerational programming to F3 following antenatal sGC. Transmission is sex- and generation-dependent, occurring through both parental lines. Paternal transmission to F3 females strongly implicates epigenetic mechanisms of transmission.

What we have learned about antenatal corticosteroid regimens

Administration of antenatal corticosteroids has been standard of care for women between 24 and 34 weeks of gestation who are at risk for preterm delivery for more than 20 years longer in other parts of the world. Although the benefit of steroids in this population has been confirmed, there remain many questions including the frequency of dosing and whether it is possible to expand the gestational age criteria to women likely to deliver before 24 weeks or after 34 weeks. The MFMU Network has played a major role in answering some of these questions.

Prescribing patterns of antenatal corticosteroids in women with threatened preterm labor

OBJECTIVE

To assess the impact of cervical length (CL) measurement and fetal fibronectin testing (fFN) on the clinicians' decision to prescribe antenatal corticosteroids (ACS) to women with symptoms of preterm labor.

STUDY DESIGN

This is a secondary analysis of a prospective cohort study including women with symptoms of preterm labor and intact membranes between 24 and 34 weeks' gestation. We compared the proportion prescribed and completed ACS courses, preterm delivery within seven days and median intervals from ACS to delivery in four groups: group 1 CL<10 mm, group 2 CL 10-30 mm and positive fFN, group 3 CL 10-30 mm and negative fFN, group 4 CL>30 mm.

RESULTS

ACS were prescribed to 63/65 (97%) women in group 1, 176/192 (91%) in group 2, 111/172 women (65%) in group 3 and 55/242 (23%) in group 4. In group 1, 42 (65%) women delivered within seven days, compared to 34 (18%) in group 2, 6 (3%) in group 3 and 3 (1%) in group 4. Median intervals between ACS and delivery were 6 days (IQR 3-61 days), 44 days (IQR 17-69 days), 53 days (IQR 37-77 days) and 66 days (IQR 43-78 days) in group 1, 2, 3 and 4 respectively.

CONCLUSION

ACS were prescribed frequently to women with a CL of 10-30 mm and a negative fFN test or a CL>30 mm. There is room for improvement in the prescription of ACS in these low risk women.

Antenatal corticosteroids for preterm premature rupture of membranes: single or repeat course?

OBJECTIVE

The aim of this article is to determine the risk of maternal chorioamnionitis and neonatal morbidity in women with preterm premature rupture of membranes (PPROM) exposed to one corticosteroid course versus a single repeat corticosteroid steroid course.

STUDY DESIGN

Secondary analysis of a cohort of women with singleton pregnancies and PPROM. The primary outcome was a clinical diagnosis of maternal chorioamnionitis. Using multivariate logistic regression, we controlled for maternal age, race, body mass index, diabetes, gestational age at membrane rupture, preterm labor, and antibiotic administration. Neonatal morbidities were compared between groups controlling for gestational age at delivery.

RESULTS

Of 1,652 women with PPROM, 1,507 women received one corticosteroid course and 145 women received a repeat corticosteroid course. The incidence of chorioamnionitis was similar between groups (single course = 12.3% vs. repeat course = 11.0%; p = 0.8). Women receiving a repeat corticosteroid course were not at increased risk of chorioamnionitis (adjusted odds ratio, 1.28; 95% confidence interval, 0.69-2.14). A repeat course of steroids was not associated with an increased risk of any neonatal morbidity.

CONCLUSION

Compared with a single steroid course, our findings suggest that the risk of maternal chorioamnionitis or neonatal morbidity may not be increased for women with PPROM receiving a repeat corticosteroid course.

Glucocorticoids and fetal programming part 1: Outcomes

Fetal development is a critical period for shaping the lifelong health of an individual. However, the fetus is susceptible to internal and external stimuli that can lead to adverse long-term health consequences. Glucocorticoids are an important developmental switch, driving changes in gene regulation that are necessary for normal growth and maturation. The fetal hypothalamic-pituitary-adrenal (HPA) axis is particularly susceptible to long-term programming by glucocorticoids; these effects can persist throughout the life of an organism. Dysfunction of the HPA axis as a result of fetal programming has been associated with impaired brain growth, altered behaviour and increased susceptibility to chronic disease (such as metabolic and cardiovascular disease). Moreover, the effects of glucocorticoid-mediated programming are evident in subsequent generations, and transmission of these changes can occur through both maternal and paternal lineages.

Different corticosteroids and regimens for accelerating fetal lung maturation for women at risk of preterm birth

BACKGROUND

Despite the widespread use of antenatal corticosteroids to prevent respiratory distress syndrome in preterm infants, there is currently no consensus as to the type of corticosteroid to use; nor the dose, frequency, timing of use or the route of administration.

OBJECTIVES

To assess the effects of different corticosteroid regimens for women at risk of preterm birth.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013).

SELECTION CRITERIA

All identified published and unpublished randomised controlled trials or quasi-randomised control trials comparing any two corticosteroids (dexamethasone or betamethasone or any other corticosteroid that can cross the placenta), comparing different dose regimens (including frequency and timing of administration) in women at risk of preterm birth were included. We planned to exclude cross-over trials and cluster-randomised trials. We included studies published as abstracts only along with studies published as full-text manuscripts

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy.

MAIN RESULTS

For this update, 12 trials (1557 women and 1661 infants) were included. Dexamethasone was associated with a reduced risk of intraventricular haemorrhage (IVH) compared with betamethasone (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.21 to 0.92; four trials, 549 infants). No statistically significant differences were seen for other primary outcomes: respiratory distress syndrome (RDS) (RR 1.06, 95% CI 0.88 to 1.27; five trials, 753 infants) and perinatal death (neonatal death RR 1.41, 95% CI 0.54 to 3.67; four trials, 596 infants). Similarly, very few differences were seen for secondary outcomes such as rate of admission to the neonatal intensive care unit (NICU) although in one trial, those infants exposed to dexamethasone, compared with betamethasone, had a significantly shorter length of NICU admission (mean difference (MD) -0.91 days, 95% CI -1.77 to -0.05; 70 infants). Results for biophysical parameters were inconsistent, but mostly no clinically important differences were seen.Compared with intramuscular dexamethasone, oral dexamethasone significantly increased the incidence of neonatal sepsis (RR 8.48, 95% CI 1.11 to 64.93) in one trial of 183 infants. No statistically significant differences were seen for other outcomes reported.Apart from a reduced maternal postpartum length of stay for women who received betamethasone at 12-hourly intervals compared to 24-hourly intervals in one trial (MD -0.73 days, 95% CI -1.28 to -0.18; 215 women), no differences in maternal or neonatal outcomes were seen between the different betamethasone dosing intervals assessed. Similarly, no significant differences in outcomes were seen when betamethasone acetate and phosphate was compared with betamethasone phosphate in one trial.

AUTHORS' CONCLUSIONS

It remains unclear whether one corticosteroid (or one particular regimen) has advantages over another.Dexamethasone may have some benefits compared with betamethasone such as less IVH, and a shorter length of stay in the NICU. The intramuscular route may have advantages over the oral route for dexamethasone, as identified in one small trial. Apart from the suggestion that 12-hour dosing may be as effective as 24-hour dosing of betamethasone based on one small trial, few other conclusions about optimal antenatal corticosteroid regimens were able to be made. No long-term results were available except for a small subgroup of 18 month old children in one trial. Trials comparing the commonly used corticosteroids are most urgently needed, as are trials of dosages and other variations in treatment regimens.

Short- and long-term effects of exposure to natural and synthetic glucocorticoids during development

1.Glucocorticoids (GCs) are necessary for fetal development, but clinical and experimental studies suggest that excess exposure may be detrimental to health in both the short and longer term. 2.Exposure of the fetus to synthetic GCs can occur if the mother has a medical condition requiring GC therapy (e.g. asthma) or if she threatens to deliver her baby prematurely. Synthetic GCs can readily cross the placenta and treatment is beneficial, at least in the short term, for maternal health and fetal survival. 3.Maternal stress during pregnancy can raise endogenous levels of the natural GC cortisol. A significant proportion of the cortisol is inactivated by the placental 'GC barrier'. However, exposure to severe stress during pregnancy can result in increased risk of miscarriage, low birth weight and behavioural deficits in children. 4.Animal studies have shown that excess exposure to both synthetic and natural GCs can alter normal organ development, including that of the heart, brain and kidney. The nature and severity of the organ impairment is dependent upon the timing of exposure and, in some cases, the type of GC used and the sex of the fetus. 5.In animal models, exposure to elevated GCs during pregnancy has been associated with adult-onset diseases, including elevated blood pressure, impaired cardiac and vascular function and altered metabolic function.

Australasian randomised trial to evaluate the role of maternal intramuscular dexamethasone versus betamethasone prior to preterm birth to increase survival free of childhood neurosensory disability (A*STEROID): study protocol

BACKGROUND

Both dexamethasone and betamethasone, given to women at risk of preterm birth, substantially improve short-term neonatal health, increase the chance of the baby being discharged home alive, and reduce childhood neurosensory disability, remaining safe into adulthood. However, it is unclear which corticosteroid is of greater benefit to mother and child.This study aims to determine whether giving dexamethasone to women at risk of preterm birth at less than 34 weeks' gestation increases the chance of their children surviving free of neurosensory disability at two years' corrected age, compared with betamethasone.

METHODS/DESIGN

Design randomised, multicentre, placebo controlled trial.Inclusion criteria women at risk of preterm birth at less than 34 weeks' gestation with a singleton or twin pregnancy and no contraindications to the use of antenatal corticosteroids and who give informed consent.Trial entry & randomisation at telephone randomisation eligible women will be randomly allocated to either the dexamethasone group or the betamethasone group, allocated a study number and corresponding treatment pack.Study groups women in the dexamethasone group will be administered two syringes of 12 mg dexamethasone (dexamethasone sodium phosphate) and women in the betamethasone group will be administered two syringes of 11.4 mg betamethasone (Celestone Chronodose). Both study groups consist of intramuscular treatments 24 hours apart.Primary study outcome death or any neurosensory disability measured in children at two years' corrected age.Sample size a sample size of 1449 children is required to detect either a decrease in death or any neurosensory disability from 27.0% to 20.1% with dexamethasone compared with betamethasone, or an increase from 27.0% to 34.5% (two-sided alpha 0.05, 80% power, 5% loss to follow up, design effect 1.2).

DISCUSSION

This study will provide high-level evidence of direct relevance for clinical practice. If one drug clearly results in significantly fewer deaths and fewer disabled children then it should be used consistently in women at risk of preterm birth and would be of great importance to women at risk of preterm birth, their children, health services and communities.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

ACTRN12608000631303.

Antenatal steroids and the IUGR fetus: are exposure and physiological effects on the lung and cardiovascular system the same as in normally grown fetuses?

Glucocorticoids are administered to pregnant women at risk of preterm labour to promote fetal lung surfactant maturation. Intrauterine growth restriction (IUGR) is associated with an increased risk of preterm labour. Hence, IUGR babies may be exposed to antenatal glucocorticoids. The ability of the placenta or blood brain barrier to remove glucocorticoids from the fetal compartment or the brain is compromised in the IUGR fetus, which may have implications for lung, brain, and heart development. There is conflicting evidence on the effect of exogenous glucocorticoids on surfactant protein expression in different animal models of IUGR. Furthermore, the IUGR fetus undergoes significant cardiovascular adaptations, including altered blood pressure regulation, which is in conflict with glucocorticoid-induced alterations in blood pressure and flow. Hence, antenatal glucocorticoid therapy in the IUGR fetus may compromise regulation of cardiovascular development. The role of cortisol in cardiomyocyte development is not clear with conflicting evidence in different species and models of IUGR. Further studies are required to study the effects of antenatal glucocorticoids on lung, brain, and heart development in the IUGR fetus. Of specific interest are the aetiology of IUGR and the resultant degree, duration, and severity of hypoxemia.

Prenatal synthetic glucocorticoid treatment changes DNA methylation states in male organ systems: multigenerational effects

Prenatal synthetic glucocorticoids (sGC) are administered to pregnant women at risk of delivering preterm, approximately 10% of all pregnancies. Animal studies have demonstrated that offspring exposed to elevated glucocorticoids, either by administration of sGC or as a result of maternal stress, are at increased risk of developing behavioral, endocrine, and metabolic abnormalities. DNA methylation is a covalent modification of DNA that plays a critical role in long-lasting programming of gene expression. Here we tested the hypothesis that prenatal sGC treatment has both acute and long-term effects on DNA methylation states in the fetus and offspring and that these effects extend into a subsequent generation. Pregnant guinea pigs were treated with sGC in late gestation, and methylation analysis by luminometric methylation assay was undertaken in organs from fetuses and offspring across two generations. Expression of genes that modify the epigenetic state were measured by quantitative real-time PCR. Results indicate that there are organ-specific developmental trajectories of methylation in the fetus and newborn. Furthermore, these trajectories are substantially modified by intrauterine exposure to sGC. These sGC-induced changes in DNA methylation remain into adulthood and are evident in the next generation. Furthermore, prenatal sGC exposure alters the expression of several genes encoding proteins that modulate the epigenetic state. Several of these changes are long lasting and are also present in the next generation. These data support the hypothesis that prenatal sGC exposure leads to broad changes in critical components of the epigenetic machinery and that these effects can pass to the next generation.

Repeated courses of antenatal corticosteroids have adverse effects on aspects of brain development in naturally delivered baboon infants

INTRODUCTION

Repeated courses of antenatal steroids in women at risk of preterm delivery have beneficial effects on lung maturation, but concern exists about the effects on brain development. We aimed to determine whether repeated courses of corticosteroids increased the risk of neuropathology as compared with single courses or no treatment.

METHODS

Single-course animals received a 6-mg dose of steroids at 123 and 124 d of gestation (dg; term, 185 dg; n = 6). Repeated-course animals received additional doses at 137 and 138 dg (n = 7). Controls received no steroids (n = 5). Baboons delivered naturally at term and necropsy was performed. Brains were assessed histologically for parameters of development and neuropathology.

RESULTS

Body weights did not differ between the groups (P > 0.05); neither did brain/body weight ratio. Density of glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytes in white matter (WM) was increased in the single- (P < 0.05) and repeated-course (P < 0.01) groups as compared with controls. Density of myelin basic protein (MBP)-IR oligodendrocytes was reduced in the repeated-course animals as compared with both the control and single-course groups (P < 0.05); oligodendrocyte transcription factor 2 (Olig2)-IR showed no difference between groups.

DISCUSSION

Repeated courses of antenatal corticosteroids have effects on myelination in the developing nonhuman primate brain, which should be taken into account when determining a dosing regimen.

Repeat prenatal corticosteroid prior to preterm birth: a systematic review and individual participant data meta-analysis for the PRECISE study group (prenatal repeat corticosteroid international IPD study group: assessing the effects using the best level of evidence) - study protocol

BACKGROUND

The aim of this individual participant data (IPD) meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol.

METHODS/DESIGN

The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE) Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants are eligible for the PRECISE IPD meta-analysis. The primary study outcomes for the infants will be serious neonatal outcome (defined by the PRECISE International IPD Study Group as one of death (foetal, neonatal or infant); severe respiratory disease; severe intraventricular haemorrhage (grade 3 and 4); chronic lung disease; necrotising enterocolitis; serious retinopathy of prematurity; and cystic periventricular leukomalacia); use of respiratory support (defined as mechanical ventilation or continuous positive airways pressure or other respiratory support); and birth weight (Z-scores). For the children, the primary study outcomes will be death or any neurological disability (however defined by trialists at childhood follow up and may include developmental delay or intellectual impairment (developmental quotient or intelligence quotient more than one standard deviation below the mean), cerebral palsy (abnormality of tone with motor dysfunction), blindness (for example, corrected visual acuity worse than 6/60 in the better eye) or deafness (for example, hearing loss requiring amplification or worse)). For the women, the primary outcome will be maternal sepsis (defined as chorioamnionitis; pyrexia after trial entry requiring the use of antibiotics; puerperal sepsis; intrapartum fever requiring the use of antibiotics; or postnatal pyrexia).

DISCUSSION

Data analyses are expected to commence in 2011 with results publicly available in 2012.

Pre-sampling ultrasound evaluation and assessment of the tissue yield during sampling improves the diagnostic reliability of office endometrial biopsy

We evaluated the implementation of a strict procedure for endometrium biopsy, including pre-sampling ultrasound examination and assessment of the tissue yield during sampling, in 257 consecutive women with abnormal bleeding. The tissue yield was assessed during sampling and scored from 1 to 4. The median endometrial thickness as measured by ultrasound was 5.0 mm, 5.1 mm, 10.0 mm and 18.7 mm for a tissue yield score of 1, 2, 3 and 4, respectively. The median endometrial thickness at ultrasound and the median tissue yield score was 18.3 mm and score 4 in the endometrial cancer cases, compared with 3.9 mm and score 1, and 14.8 mm and score 3 in the case of endometrial atrophy and hyperplasia, respectively; and 11.5 mm and score 2 in endometrial polyp cases. Overall, 12 cancers were diagnosed. No endometrial cancer was diagnosed during follow-up (median 447 days). A strict office endometrial biopsy procedure contributes to the diagnostic reliability for intracavitary pathology.

Dexamethasone induces fetal developmental toxicity through affecting the placental glucocorticoid barrier and depressing fetal adrenal function

This study evaluates the neuroendocrine-interference mechanism underlying dexamethasone-induced developmental toxicity. Pregnant mice were treated with various doses of dexamethasone (0, 0.5, 2.0 and 8.0mg/kg), corticosterone levels in maternal serum, mRNA expressions of maternal and fetal adrenal steroidogenic acute regulatory protein (StAR), cytochrome P450 responsible for cholesterol side chain cleavage (P450scc) and placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2) were measured. And the expressions of StAR and P450scc were also measured in cultured primary human fetal adrenocortical cells treated with various concentrations of dexamethasone (0, 1, 10 and 100 μmol/L) for 24h. Mice suffered from intrauterine growth retardation (IUGR) after exposure to dexamethasone. The IUGR rate was augmented to 42.9% and 95.7% in 2.0 and 8.0mg/kg dexamethasone groups, respectively (P<0.01). The level of maternal serum corticosterone in three dexamethasone groups were decreased to 31.8%, 34.8% and 32.9%, respectively (P<0.05 or P<0.01), as compared with the control. Furthermore, the mRNA expressions of maternal and fetal adrenal StAR and P450scc in 8.0mg/kg dexamethasone groups were decreased to 19.3% and 10.8%, 11.0% and 9.9% of that in the corresponding controls, respectively (P<0.05). The mRNA expressions of placental 11β-HSD-2 were dose-dependently reduced in dexamethasone groups, particularly, the mRNA decreased to 22.2% in 8.0mg/kg dexamethasone group, as compared with the control (P=0.15). No obvious changes of StAR and P450scc in vitro after dexamethasone treatment. These suggest that prenatal dexamethasone exposure induces fetal developmental toxicity. A possible underlying mechanism is that dexamethasone may affect the placental glucocorticoid barrier and depressing fetal adrenal function.

Repeated antenatal corticosteroid treatments adversely affect neural transmission time and auditory thresholds in laboratory rats

Antenatal corticosteroid (AC) treatment is given to pregnant women at risk for preterm birth to reduce infant morbidity and mortality by enhancing lung and brain maturation. However, there is no accepted regimen on how frequently AC treatments should be given and some studies found that repeated AC treatments can cause growth retardation and brain damage. Our goal was to assess the dose-dependent effects of repeated AC treatment and estimate the critical number of AC courses to cause harmful effects on the auditory brainstem response (ABR), a sensitive measure of brain development, neural transmission and hearing loss. We hypothesized that repeated AC treatment would have harmful effects on the offspring's ABRs and growth only if more than 3 AC treatment courses were given. To test this hypothesis, pregnant Wistar rats were given either a high regimen of AC (HAC), a moderate regimen (MAC), a low regimen (LAC), or saline (SAL). An untreated control (CON) group was also used. Simulating the clinical condition, the HAC dams received 0.2mg/kg Betamethasone (IM) twice daily for 6 days during gestation days (GD) 17-22. The MAC dams received 3 days of AC treatment followed by 3 days of saline treatment on GD 17-19 and GD 20-22, respectively. The LAC dams received 1 day of AC treatment followed by 5 days of saline treatment on GD 17 and GD 18-22, respectively. The SAL dams received 6 days of saline treatment from GD 17 to 22 (twice daily, isovolumetric to the HAC injections, IM). The offspring were ABR-tested on postnatal day 24. Results indicated that the ABR's P4 latencies (neural transmission time) were significantly prolonged (worse) in the HAC pups and that ABR's thresholds were significantly elevated (worse) in the HAC and MAC pups when compared to the CON pups. The HAC and MAC pups were also growth retarded and had higher postnatal mortality than the CON pups. The SAL and LAC pups showed little or no adverse effects. In conclusion, repeated AC treatment had harmful effects on the rat offspring's ABRs, postnatal growth and survival. The prolonged ABR latencies reflect slowed neural transmission times along the auditory nerve and brainstem auditory pathway. The elevated ABR thresholds reflect hearing deficits. We concluded that repeated AC treatment can have harmful neurological, sensory and developmental effects on the rat offspring. These effects should be considered when weighing the benefits and risks of repeated AC treatment and when monitoring and managing the prenatally exposed child for possible adverse effects.

Antenatal corticosteroids for preterm birth: dose-dependent reduction in birthweight, length and head circumference

AIM

This study was undertaken to evaluate the effects of repeated courses of antenatal corticosteroids (ACS) on foetal growth.

METHODS

We studied 94 infants exposed to 2-9 courses of ACS. Mean gestational age (GA) at first exposure was 29 and at birth 34 weeks. Exposure data were retrieved from case record files. Information on potential confounders was collected from the Swedish Medical Birth Registry. Standard deviation scores (SDS) for birthweight (BW), birthlength (BL) and head circumference (HC) were calculated and considered as outcomes.

RESULTS

GA at start of ACS did not affect outcome. BW-SDS, BL-SDS and HC-SDS were -0.21, -0.19 and +0.25 in infants exposed to two courses, compared to -1.01, -1.04 and -0.23 in infants exposed to ≥ 4 courses of ACS (p = 0.04-0.07). In multiple regression analyses, ≥ 4 courses were associated with lower BW-SDS, BL-SDS and HC-SDS (p = 0.007-0.04) compared to SDS after 2-3 courses. The effects from ≥ 4 courses on BW and BL were comparable to reduction in birth size seen in twins and on HC to that observed after maternal smoking.

CONCLUSIONS

Multiple courses of ACS are associated with a dose-dependent decline in foetal growth, which may affect later development and health.

Prenatal synthetic glucocorticoid exposure alters hypothalamic-pituitary-adrenal regulation and pregnancy outcomes in mature female guinea pigs

Preterm delivery occurs in approximately 10% of all pregnancies. Prenatal exposure to synthetic glucocorticoids (sGCs) reduces the incidence of respiratory distress syndrome (RDS) in these babies. Therefore, administration of multiple courses of sGCs became common practice. Animal and human studies have demonstrated that multiple courses of sGCs can have long-term effects. While the majority of animal studies have been undertaken in male offspring, it is emerging that there are profound sex differences in the consequences of prenatal sGC exposure. To our knowledge, no studies have determined the effects of prenatal sGC exposure on hypothalamic-pituitary-adrenal (HPA) axis function in female offspring while accounting for reproductive cycle status, or determined if there are effects on pregnancy parameters. Pregnant guinea pigs were administered three courses of betamethasone (Beta), dexamethasone (Dex) or vehicle on gestational days 40/41, 50/51 and 60/61. In adulthood (age range: postnatal days 126-165), basal and activated HPA axis function were assessed at various stages of the reproductive cycle. The female offspring were then mated and underwent an undisturbed pregnancy. Females were killed in the luteal phase of the reproductive cycle following litter weaning, and molecular analysis undertaken. In the luteal phase, Beta-exposed females exhibited significantly lower basal salivary cortisol levels (P < 0.05). Dex-exposed females also exhibited significantly lower basal salivary cortisol levels during the luteal phase (P < 0.05), but increased basal salivary cortisol levels during the ostrous phase (P < 0.01). The Beta-exposed females exhibited increased glucocorticoid receptor (GR) mRNA expression in the CA1/2 region of the hippocampus (P < 0.05) and MC2R mRNA in the adrenal cortex (P < 0.05). The Dex-exposed animals exhibited higher hippocampal GR and mineralocorticoid receptor (MR) mRNA levels (P < 0.05). Beta-exposed females showed reduced fecundity (P < 0.05). In Dex-exposed females there was a lower male to female sex ratio. In conclusion, prenatal sGC exposure affects HPA axis activity, in a cycle-dependent manner, and long-term reproductive success. The clinical implications of the findings on endocrine function and pregnancy in females are profound and further follow-up is warranted in human cohorts. Furthermore, we have shown there are considerable difference in phenotypes between the Beta- and Dex-exposed females and the specific endocrine and maternal outcome is contingent on the specific sGCs administered during pregnancy.

Should we be prescribing repeated courses of antenatal corticosteroids?

Single-course treatment with antenatal corticosteroids has been shown to enhance fetal maturation before preterm birth and to improve outcomes for the preterm infant. Based on this success, practitioners expanded use of the treatment to repeated courses of antenatal corticosteroids ahead of evidence demonstrating benefit and excluding harm. Experiments with animals and cohort studies have provided a body of evidence suggesting that repeated doses may further improve lung maturation but may be accompanied by deleterious effects on the developing brain and other organs. Randomised controlled trials of repeated treatments to date have provided mixed evidence but in general may indicate a small benefit in terms of postnatal lung function, but this is accompanied by restricted growth which may include the brain. In view of the well-established role that corticosteroids are known to play in brain development, and the marginal difference that repeated courses may make to outcome in the context of modern neonatal care, antenatal corticosteroid treatments should be restricted to single-course treatment.

Antenatal corticosteroid treatment: what's happened since Drs Liggins and Howie?

In 1972, Drs Liggins and Howie published a landmark article demonstrating that antenatal corticosteroids significantly reduced the frequency of respiratory distress syndrome and neonatal mortality. A single course of antenatal corticosteroids has become standard of care for pregnant women at risk for preterm birth. Recent studies have suggested weekly courses of antenatal corticosteroids result in improvement in the acute neonatal condition but have not supported long-term benefit. With greater understanding of the beneficial actions of corticosteroids on the fetal lung, the role for this therapy may expand. In addition to increased surfactant production and secretion, corticosteroids facilitate clearance of fetal lung fluid, as well as other maturational effects. Thus, antenatal corticosteroids may prove valuable in the late preterm period and before elective cesarean delivery at term.

Multiple courses of antenatal corticosteroids for preterm birth (MACS): a randomised controlled trial

BACKGROUND

One course of antenatal corticosteroids reduces the risk of respiratory distress syndrome and neonatal death. Weekly doses given to women who remain undelivered after a single course may have benefits (less respiratory morbidity) or cause harm (reduced growth in utero). We aimed to find out whether multiple courses of antenatal corticosteroids would reduce neonatal morbidity and mortality without adversely affecting fetal growth.

METHODS

1858 women at 25-32 weeks' gestation who remained undelivered 14-21 days after an initial course of antenatal corticosteroids and continued to be at high risk of preterm birth were randomly assigned to multiple courses of antenatal corticosteroids (n=937) or placebo (n=921), every 14 days until week 33 or delivery, whichever came first. The primary outcome was a composite of perinatal or neonatal mortality, severe respiratory distress syndrome, intraventricular haemorrhage (grade III or IV), periventricular leucomalacia, bronchopulmonary dysplasia, or necrotising enterocolitis. Analysis was by intention to treat. All patients and caregivers were unaware of the treatment given. This trial is registered as number ISRCTN2654148.

FINDINGS

Infants exposed to multiple courses of antenatal corticosteroids had similar morbidity and mortality to those exposed to placebo (150 [12.9%] vs 143 [12.5%]). Those receiving multiple doses of corticosteroids also weighed less at birth than those exposed to placebo (2216 g vs 2330 g, p=0.0026), were shorter (44.5 cm vs 45.4 cm, p<0.001), and had a smaller head circumference (31.1 cm vs 31.7 cm, p<0.001).

INTERPRETATION

Multiple courses of antenatal corticosteroids, every 14 days, do not improve preterm-birth outcomes, and are associated with a decreased weight, length, and head circumference at birth. Therefore, this treatment schedule is not recommended.

FUNDING

Canadian Institutes of Health Research.

Effects of prenatal dexamethasone treatment on physical growth, pituitary-adrenal hormones, and performance of motor, motivational, and cognitive tasks in juvenile and adolescent common marmoset monkeys

Synthetic glucocorticoids such as dexamethasone (DEX) are commonly used to prevent respiratory distress syndrome in preterm infants, but there is emerging evidence of subsequent neurobehavioral abnormalities (e.g. problems with inattention/hyperactivity). In the present study, we exposed pregnant common marmosets (Callithrix jacchus, primates) to daily repeated DEX (5 mg/kg by mouth) during either early (d 42-48) or late (d 90-96) pregnancy (gestation period of 144 days). Relative to control, and with a longitudinal design, we investigated DEX effects in offspring in terms of physical growth, plasma ACTH and cortisol titers, social and maintenance behaviors, skilled motor reaching, motivation for palatable reward, and learning between infancy and adolescence. Early DEX resulted in reduced sociability in infants and increased motivation for palatable reward in adolescents. Late DEX resulted in a mild transient increase in knee-heel length in infants and enhanced reversal learning of stimulus-reward association in adolescents. There was no effect of either early or late DEX on basal plasma ACTH or cortisol titers. Both treatments resulted in impaired skilled motor reaching in juveniles, which attenuated in early DEX but persisted in late DEX across test sessions. The increased palatable-reward motivation and decreased social motivation observed in early DEX subjects provide experimental support for the clinical reports that prenatal glucocorticoid treatment impairs social development and predisposes to metabolic syndrome. These novel primate findings indicate that fetal glucocorticoid overexposure can lead to abnormal development of motor, affective, and cognitive behaviors. Importantly, the outcome is highly dependent upon the timing of glucocorticoid overexposure.

Different corticosteroids and regimens for accelerating fetal lung maturation for women at risk of preterm birth

BACKGROUND

Despite the widespread use of antenatal corticosteroids to prevent respiratory distress syndrome in preterm infants, there is currently no consensus as to the type of corticosteroid to use; nor the dose, frequency or timing of use or the route of administration.

OBJECTIVES

To assess the effects of different corticosteroid regimens for women at risk of preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of antenatal corticosteroid regimens in women at risk of preterm birth.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted the data independently.

MAIN RESULTS

Ten trials (1089 women and 1161 infants) were included. Dexamethasone decreased the incidence of intraventricular haemorrhage compared with betamethasone (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.21 to 0.92; four trials, 549 infants). No statistically significant differences were seen for other primary outcomes including respiratory distress syndrome, bronchopulmonary dysplasia, severe intraventricular haemorrhage, periventricular leukomalacia, perinatal death, or mean birthweight. Results for biophysical parameters were inconsistent, but mostly no important differences were seen for these, or any other secondary outcome except for neonatal intensive care unit (NICU) admission. In one trial of 105 infants, significantly more infants in the dexamethasone group were admitted to NICU compared with the betamethasone group (RR 3.83, 95% CI 1.24 to 11.87).Oral dexamethasone compared with intramuscular dexamethasone increased the incidence of neonatal sepsis (RR 8.48, 95% CI 1.11 to 64.93) in one trial of 183 infants. No statistically significant differences were seen for other outcomes reported.In one small trial of 69 infants comparing betamethasone acetate and phosphate with betamethasone phosphate no differences were seen for any of the outcomes reported.

AUTHORS' CONCLUSIONS

Dexamethasone may have some benefits compared with betamethasone such as less intraventricular haemorrhage, although perhaps a higher rate of NICU admission (seen in only one trial). Apart from a suggestion from another small trial that the intramuscular route may have advantages over an oral route for dexamethasone, few other conclusions about optimal antenatal corticosteroid regimens were able to be made. Trials of commonly used corticosteroids are most urgently needed, followed by trials of dosages and other variations in regimens.

Repeated betamethasone treatment of pregnant sheep programs persistent reductions in circulating IGF-I and IGF-binding proteins in progeny

Exposure to synthetic glucocorticoids in utero markedly improves survival after preterm birth, but repeated exposures impair fetal and postnatal growth and are associated with evidence of insulin resistance in later life. The insulin-like growth factor (IGF) axis is an important regulator of growth and metabolism before and after birth. We have therefore investigated the effects of repeated maternal betamethasone injections on plasma IGF-I, IGF-II, and IGF-binding proteins (IGFBP) in fetal and postnatal progeny in the sheep. Pregnant sheep carrying male fetuses were injected with saline or betamethasone at 104, 111, and 118 days of gestation (dG, term approximately 150 dG). Plasma samples were collected postmortem from fetuses before (75, 84, 101 dG) or after one (109 dG), two (116 dG), or three (121-122, 132-133, 145-147 dG) doses of saline or betamethasone and from progeny at 42 and 84 days of age. Fetal weight was reduced after two or more maternal betamethasone injections, and this effect persisted to term. Repeated betamethasone exposures reduced plasma IGF-I and total IGFBP in fetuses at 133 dG and progeny at 84 days, and reduced plasma IGFBP-3 at 84 days. Fetal plasma IGF-II tended to increase transiently at 109 dG following the first betamethasone injection. Fetal, placental, and/or postnatal weights correlated positively with concomitant plasma IGF-I, IGF-II, and total IGFBP. We conclude that repeated exposure to synthetic glucocorticoids in utero programs the IGF axis before and after birth, which may contribute to the adverse effects of betamethasone exposure on growth and metabolism.

Long-term outcomes after repeat doses of antenatal corticosteroids

BACKGROUND

Previous trials have shown that repeat courses of antenatal corticosteroids improve some neonatal outcomes in preterm infants but reduce birth weight and increase the risk of intrauterine growth restriction. We report long-term follow-up results of children enrolled in a randomized trial comparing single and repeat courses of antenatal corticosteroids.

METHODS

Women at 23 through 31 weeks of gestation who remained pregnant 7 days after an initial course of corticosteroids were randomly assigned to weekly courses of betamethasone, consisting of 12 mg given intramuscularly and repeated once at 24 hours, or an identical-appearing placebo. We studied the children who were born after these treatments when they were between 2 and 3 years of corrected age. Prespecified outcomes included scores on the Bayley Scales of Infant Development, anthropometric measurements, and the presence of cerebral palsy.

RESULTS

A total of 556 infants were available for follow-up; 486 children (87.4%) underwent physical examination and 465 (83.6%) underwent Bayley testing at a mean (+/-SD) corrected age of 29.3+/-4.6 months. There were no significant differences in Bayley results or anthropometric measurements. Six children (2.9% of pregnancies) in the repeat-corticosteroid group had cerebral palsy as compared with one child (0.5% of pregnancies) in the placebo group (relative risk, 5.7; 95% confidence interval, 0.7 to 46.7; P=0.12).

CONCLUSIONS

Children who had been exposed to repeat as compared with single courses of antenatal corticosteroids did not differ significantly in physical or neurocognitive measures. Although the difference was not statistically significant, the higher rate of cerebral palsy among children who had been exposed to repeat doses of corticosteroids is of concern and warrants further study. (ClinicalTrials.gov number, NCT00015002 [ClinicalTrials.gov].).

Fetal programming of hypothalamic-pituitary-adrenal (HPA) axis function and behavior by synthetic glucocorticoids

Reduced fetal growth has been closely associated with an increased risk for the development of chronic disease in later life. Accumulating evidence indicates that fetal exposure to excess glucocorticoids represents a critical mechanism underlying this association. Approximately 7% of pregnant women are at risk of preterm delivery and these women are routinely treated with synthetic glucocorticoids (sGC) between 24 and 34 of weeks gestation to improve neonatal outcome. Animal studies have demonstrated that maternally administered sGC crosses the placenta, affecting fetal hypothalamic-pituitary-adrenal (HPA) development, resulting in changes in HPA axis function that persist throughout life. These changes appear to be modulated at the level of glucocorticoid receptors (GR) and mineralocorticoid receptors (MR) in the brain and pituitary. As the HPA axis interacts with many other physiological pathways, the changes in endocrine function are also sex-specific and age-dependent. Alterations in behavior, particularly locomotion, in animals exposed to sGC in utero have also been demonstrated. Consistent with the finding in animal models, emerging human data are indicating attention deficit-hyperactivity disorder (ADHD)-like symptoms in children exposed to repeated courses of sGC in utero. This behavioral phenotype is likely linked to alterations in dopamine (DA) signaling, suggesting that sGC are able to permanently modify or 'program' this system. Finally, it is emerging that changes in HPA axis function and behavior following antenatal exposure to sGC are transgenerational and likely involve epigenetic mechanisms. A comprehensive understanding of the acute and long-term impact of sGC exposure in utero is necessary to begin to develop recommendations and treatment options for pregnant women at risk of preterm delivery.

Repeat doses of antenatal steroids and hypothalamic-pituitary-adrenal axis (HPA) function

OBJECTIVE

This study was undertaken to compare the effects of exposure to repeated courses of antenatal steroids with those of a single course on hypothalamic-pituitary-adrenal axis function.

STUDY DESIGN

Women at risk of premature delivery were assessed for entry into a randomized controlled trial of repeated courses of corticosteroids (ACTORDS). If a woman declined the randomized trial then consent was sought for collection of observational data. Baseline bloods for cortisol and adrenocorticotropic hormone levels were collected and in a subset of infants a metyrapone test performed.

RESULTS

In the 86 studied infants, cortisol and adrenocorticotropic hormone levels did not differ between those exposed to single and repeated courses of antenatal steroids (P = .53 and P = .15, respectively). Although cortisol levels fell in response to metyrapone (P = .03) this response was not different between the single and repeated course groups (P = .46).

CONCLUSION

Repeated courses of antenatal steroids do not cause important hypothalamic-pituitary-adrenal axis suppression in the neonate.

Effects of repeated prenatal glucocorticoid exposure on long-term potentiation in the juvenile guinea-pig hippocampus

Synthetic glucocorticoids (sGCs) are routinely used to treat women at risk of preterm labour to promote fetal lung maturation. There is now strong evidence that exposure to excess glucocorticoid during periods of rapid brain development has permanent consequences for endocrine function and behaviour in the offspring. Prenatal exposure to sGC alters the expression of N-methyl-D-aspartate receptor (NMDA-R) subunits in the fetal and neonatal hippocampus. Given the integral role of the NMDA-R in synaptic plasticity, we hypothesized that prenatal sGC exposure will have effects on hippocampal long-term potentiation (LTP) after birth. Further, this may occur in either the presence or absence of elevated cortisol concentrations, in vitro. Pregnant guinea-pigs were injected with betamethasone (Beta, 1 mg kg(-1)) or vehicle on gestational days (gd) 40, 41, 50, 51, 60 and 61 (term approximately 70 days), a regimen comparable to that given to pregnant women. On postnatal day 21, LTP was examined at Schaffer collateral synapses in the CA1 region of hippocampal slices prepared from juvenile animals exposed to betamethasone or vehicle, in utero. Subsequently, the acute glucocorticoid receptor (GR)- and mineralocorticoid receptor (MR)-dependent effects of cortisol (0.1-10 microM; bath applied 30 min before LTP induction) were examined. There was no effect of prenatal sGC treatment on LTP under basal conditions. The application of 10 microM cortisol depressed excitatory synaptic transmission in all treatment groups regardless of sex. Similarly, LTP was depressed by 10 microM cortisol in all groups, with the exception of Beta-exposed females, in which LTP was unaltered. Hippocampal MR and GR protein levels were increased in Beta-exposed females, but not in any other prenatal treatment group. This study reveals sex-specific effects of prenatal exposure to sGC on LTP in the presence of elevated cortisol, a situation that would occur in vivo during stress.

Prenatal glucocorticoid exposure alters hypothalamic-pituitary-adrenal function in juvenile guinea pigs

The neurodevelopmental consequences of prenatal glucocorticoid exposure are not well-understood, particularly in species that give birth to neuroanatomically mature offspring. In the present study, we hypothesised that repeated prenatal glucocorticoid administration would alter hypothalamo-pituitary-adrenal (HPA) function in juvenile guinea pig offspring. Pregnant guinea pigs were injected with betamethasone (1 mg/kg) or vehicle on gestational days 40, 41, 50, 51, 60 and 61 (six doses). Prenatal glucocorticoid exposure abolished the pituitary-adrenal response to maternal separation in juvenile males, but had no effect in female offspring. Indeed, female offspring (vehicle and betamethasone) did not mount a significant HPA response to separation at 10 days of age. Although there were no effects of prenatal glucocorticoid exposure on hippocampal or hypothalamic corticosteroid receptor expression or corticotrophin-releasing factor (CRF) mRNA, there were significant effects in the pituitary and adrenal; again males were more affected than females. Prenatal glucocorticoid exposure increased pituitary pro-opiomelanocortin and CRF receptor mRNA, and markedly decreased adrenocortical CYP17 mRNA. In conclusion, repeated prenatal glucocorticoid exposure has profound influences on HPA function and regulation in the juvenile guinea pig, and this involves altered regulation at the level of the pituitary and adrenal cortex. Furthermore, juvenile males appear to be more vulnerable to the effects of prenatal glucocorticoid exposure than females.

Repeated maternal glucocorticoid treatment affects activity and hippocampal NMDA receptor expression in juvenile guinea pigs

The behavioural consequences of prenatal glucocorticoid exposure are not well understood, though emerging studies in humans indicate hyperactivity and altered cognitive development can occur. Further, recent reports indicate that N-methyl-d-aspartate receptors (NMDARs) may mediate the development of postnatal stress behaviours. We hypothesized that prenatal betamethasone (Beta) administration would alter behaviour and the expression of hippocampal NMDAR subunits NR1, NR2A and NR2B in juvenile guinea pig offspring. We found that repeated maternal Beta (1 mg kg(-1)) treatment on gestational days (gd) 40/41, 50/51 and 60/61 (term approximately 70 days) had no significant effect on birthweight or early growth. However, Beta produced sex-specific effects on open-field activity and hippocampal NMDAR subunit expression compared with controls. Female Beta offspring exhibited significantly increased locomotor activity while there was no effect in Beta males. Beta males exhibited a tendency for decreased anxiety-like behaviour. With respect to NMDAR subunit expression, Beta-exposed females exhibited significantly reduced NR1 mRNA in CA1/2 and CA3 subfields of the hippocampus; there were no effects in Beta males. In conclusion, repeated maternal treatment with Beta, in a similar regimen to that administered to pregnant women at risk of delivering preterm, has profound consequences on behaviour and development of crucial neurotransmitter systems in postnatal life.

Effects of multiple courses of antenatal corticosteroids on blood-brain barrier permeability in the ovine fetus

OBJECTIVE

To test the hypothesis that multiple courses of antenatal corticosteroids accentuate the decreases in blood-brain barrier permeability observed after a single course of corticosteroids in preterm ovine fetuses.

METHODS

Chronically instrumented 106-day gestation ovine fetuses were studied after single and multiple courses of dexamethasone or placebo were given to ewes beginning at 104 to 106 or 76 to 78 days of gestation, respectively. In the single-course groups, the ewes received dexamethasone (6 mg, n = 6) or placebo (n = 6) as four intramuscular injections every 12 hours over 48 hours. In the multiple course groups, the ewes received the same treatment (dexamethasone, n = 9, or placebo, n = 8), once per week for 5 weeks starting at 76 to 78 days of gestation. Blood-brain barrier permeability was quantified with the blood-to-brain transfer constant (K(i)) for alpha-aminoisobutyric acid (AIB) in the brain regions of the fetuses 12 hours after the last injection of dexamethasone was given to the ewes at 106 to 107 days of gestation.

RESULTS

Both single (analysis of variance [ANOVA]; main effects for dexamethasone treatment, F = 5.92, P <.04) and multiple (ANOVA; main effects for dexamethasone treatment, F = 4.74, P <.04) courses of antenatal corticosteroids were associated with decreases in blood-brain barrier permeability in the brain regions of the ovine fetus. However, the multiple courses did not accentuate (ANOVA; main effects for single versus multiple courses, F = 1.06, P = .32) the decreases in permeability observed after a single course.

CONCLUSION

Contrary to our hypothesis, antenatal treatment with a 5-week course of corticosteroids did not accentuate the reductions in blood-brain barrier permeability that we observed after a single course of corticosteroids in the fetus.

Fetal programming of hypothalamo-pituitary-adrenal function: prenatal stress and glucocorticoids

Prenatal stress (PS) and maternal exposure to exogenous glucocorticoids can lead to permanent modification of hypothalamo-pituitary-adrenal (HPA) function and stress-related behaviour. Both of these manipulations lead to increased fetal exposure to glucocorticoids. Glucocorticoids are essential for many aspects of normal brain development, but exposure of the fetal brain to an excess of glucocorticoids can have life-long effects on neuroendocrine function. Both endogenous glucocorticoid and synthetic glucocorticoid exposure have a number of rapid effects in the fetal brain, including modification of neurotransmitter systems and transcriptional machinery. Such fetal exposure permanently alters HPA function in prepubertal, postpubertal and ageing offspring, in a sex-dependent manner. Prenatal stress and exogenous glucocorticoid manipulation also lead to the modification of behaviour, brain and organ morphology, as well as altered regulation of other endocrine systems. It is also becoming increasingly apparent that the timing of exposure to PS or synthetic glucocorticoids has tremendous effects on the nature of the phenotypic outcome. Permanent changes in endocrine function will ultimately impact on health in both human and animal populations.

Use of systemic glucocorticosteroids in pregnancy: Be alert but not alarmed

SUMMARY Concerns have been raised regarding the use of repeated courses of systemic glucocorticosteroids given to pregnant women with threatened premature labour to improve fetal lung maturity. Most worrying are animal studies showing detrimental effects on the developing brain, though human data to date are conflicting. Additional concerns relate to the fetal origins of adult diseases, particularly vascular diseases such as hypertension and atherosclerosis. It is currently recommended that obstetricians give only a single course of antenatal corticosteroids to pregnant women to enhance lung maturity instead of giving repeated doses, which was previously a common practice. Other clinicians including dermatologists, gastroenterologists and rheumatologists may have reason to provide systemic glucocorticosteroids to pregnant women. Although systemic glucocorticosteroids all cross the placenta to some degree, the extent to which they do so depends on the drug involved. The choice of systemic glucocorticosteroid for the pregnant women in light of this evolving literature is discussed.

Neonatal morbidity and growth in very low birth-weight infants after multiple courses of antenatal steroids

OBJECTIVE

To evaluate the neonatal morbidity and the growth in very low birth-weight (VLBW) infants after exposure to multiple courses of antenatal steroids.

STUDY DESIGN

A total of 319 VLBW infants were placed in one of the two groups based on exposure to antenatal steroids: Group 1: less than two complete courses; Group 2: two complete courses or more. Anthropometric measurements at birth and discharge and neonatal morbidity were recorded. Composite morbidity was defined as presence of any of the following: death, chronic lung disease, major intraventricular hemorrhage and periventricular leukomalacia.

RESULTS

The composite morbidity was not significantly different between the two groups (p=0.26). A significantly higher percentage of infants born after multiple courses of antenatal steroids had head circumference below 10th percentile at discharge (23 vs 9%, adjusted OR, 3.25, (95% CI, 1.4, 7.3); p=0.015).

CONCLUSIONS

Multiple courses of antenatal steroids may predispose VLBW infants to impairment of postnatal somatic growth without providing any additional benefit for immediate neonatal outcome.

Repeated maternal dexamethasone treatments in late gestation increases 11β-hydroxysteroid dehydrogenase type 1 expression in the hippocampus of the newborn rat

This study was designed to investigate the effect of repeated maternal injections of dexamethasone in late gestation on the expression of newborn hippocampal 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), the enzyme amplifying glucocorticoids' action by converting biologically inactive 11-ketone metabolites into active glucocorticoids. Daily dexamethasone treatments (0.10 mg/kg body weight) in the last week of gestation were carried out in the pregnant rat. The expression of 11beta-HSD1 in the newborn hippocampal tissue was analyzed with Western blot and real-time polymerase chain reaction (PCR). The effect of corticosterone on the expression of 11beta-HSD1 was studied in cultured hippocampal neurons derived from newborn offspring received prenatal dexamethasone treatments. Both body and brain weights of the offspring were reduced significantly by repeated dexamethasone treatments in the last week of gestation. Western blot and real-time PCR analysis showed that both 11beta-HSD1 protein and mRNA expressions were increased significantly in the hippocampus of the newborn offspring on the first and seventh days after birth. Corticosterone could induce 11beta-HSD1 expression in cultured hippocampal neurons prepared from newborns received prenatal dexamethasone treatments, which was blocked by glucocorticoid receptor antagonist RU38486. The above findings suggest that repeated prenatal dexamethasone treatments at the end of gestation increase 11beta-HSD1 expression in the hippocampal tissue of the offspring, which may trigger a positive feedback pathway for the generation of biologically active glucocorticoids in the hippocampal tissue of the newborns.

Assessing the benefits of health research: lessons from research into the use of antenatal corticosteroids for the prevention of neonatal respiratory distress syndrome

Do the benefits from health research justify the resources devoted to it? Addressing this should not only meet increasing accountability demands, but could also enhance understanding of research utilisation and how best to organise health research systems to increase the benefits. The process from basic research to eventual application and patient benefit is usually complex. The use of antenatal corticosteroids when preterm delivery is expected has featured large in the debates about research utilisation and provides an insight into these complexities. Based on an analysis of previous modelling of research utilisation and payback assessment, a framework is developed in which the existing literature on the use of corticosteroids, combined with new material developed by the authors, can be reviewed and synthesised. The move from animal studies to human trials was undertaken by the same individual. Some early clinical application of the findings occurred concurrently with a series of further trials. Nevertheless, the implementation of these findings stalled rather than accelerated as is predicted by some models. The eventual systematic review of the trials played a part in the development of the Cochrane Collaboration and increased the impact on practice. Further implementation approaches were used in various countries, including clinical guidelines, a National Institutes of Health Consensus Conference, and various implementation projects within the UK. This paper shows how an assessment of the benefits from this stream of research and utilisation projects can be constructed. It concludes that the application of a model for assessing payback can help to demonstrate the benefits from the research in this field and enhance our understanding of research utilisation.

RETRACTED: Maternal adversity, glucocorticoids and programming of neuroendocrine function and behaviour

The fetus may be exposed to increased endogenous glucocorticoid or synthetic glucocorticoid in late gestation. Approximately 7% of pregnant women in Europe and North America are treated with synthetic glucocorticoid to promote lung maturation in fetuses at risk of preterm delivery. Very little is known about the mechanisms by which synthetic glucocorticoid or prenatal stress influence neurodevelopment in the human, or whether specific time windows of increased sensitivity exist. Glucocorticoids are essential for many aspects of normal brain development, but exposure of the fetal brain to excess glucocorticoid can have life-long effects on neuroendocrine function and behaviour. Both endogenous glucocorticoid and synthetic glucocorticoid exposure have a number of rapid effects in the fetal brain, including modification of neurotransmitter systems and transcriptional machinery. Such fetal exposure permanently alters hypothalamo-pituitary-adrenal (HPA) function in prepubertal, postpubertal and aging offspring, in a sex-dependent manner. Prenatal glucocorticoid manipulation also leads to modification of behaviour, brain and organ morphology, as well as altered regulation of other endocrine systems. Permanent changes in endocrine function will impact on health, since elevated cumulative exposure to endogenous glucocorticoid is linked to the premature onset of pathologies associated with aging.

Neurodevelopmental outcome of very low birth weight infants after multiple courses of antenatal corticosteroids

OBJECTIVE

To determine if two or more courses of antenatal corticosteroids are associated with neurodevelopmental impairment.

METHODS

All infants born at Northwestern Memorial Hospital between 1995 and 1998, who met the following criteria, were identified: birth weight < or = 1500 g, gestational age between 24 and 34 weeks, recipient of antenatal corticosteroids, and subsequent neurodevelopmental evaluation in multidisciplinary developmental evaluation clinic. The outcomes of these infants were compared according to degree of corticosteroid exposure. This study had 80% power to detect a difference in the mental development index score of 10% or a relative risk of neurodevelopmental delay of 2.5 in the group receiving at least two courses of corticosteroids.

RESULTS

Ninety-three infants were exposed to less than two full courses and 33 infants were exposed to at least two full courses of corticosteroids. The mean duration of follow-up was similar in the two groups (25 months vs 30 months, respectively, P >.05). The two groups had similar neonatal outcomes, and had no differences in any measures of neurodevelopmental outcome on follow-up.

CONCLUSION

Repeated courses of antenatal corticosteroids are not associated with increased incidence of abnormalities on subsequent neurodevelopmental outcome measures.