The effect of multidose antenatal betamethasone on maternal and infant outcomes

Antenatal Glucocorticoids Reduce the Incidence of Refractory Hypotension in Low Birthweight Infants during the Early Neonatal Period, but Do Not Affect It beyond This Time

OBJECTIVE

This study aimed to clarify the effect of antenatal glucocorticoids (AGs) on the incidence of refractory hypotension (RH) in very low birthweight (VLBW) infants after the first week of life.

STUDY DESIGN

We included VLBW infants born at a gestational age of <30 weeks and divided them into three groups: the complete group (born within 7 days of completing a single course [two doses] of AGs), the incomplete group (born without complete course), and the late delivery group (born at ≥8 days after a single course). We compared the incidence and period of onset of RH among the three groups.

RESULTS

A total of 115 infants were enrolled. The incidence of RH in the first week of life was significantly lower in the complete group than in the other groups. However, there was no significant difference in the incidence of RH after the first week of life among the groups.

CONCLUSION

AGs contribute to circulatory stabilization during the first week of life, but this effect does not last after 1 or 2 weeks of administration. In infants who receive AGs, physicians should consider that the risk of RH after the first week of life is not low.

Effects of Multiple Courses of Antenatal Corticosteroids on Regional Brain and Somatic Tissue Water Content in Ovine Fetuses

OBJECTIVE

To study the effects of single and multiple courses of antenatal corticosteroids on tissue water content in ovine fetuses.

METHODS

After chronic catheterization of the ewes and fetuses, the ewes were randomly assigned to receive single or multiple courses of dexamethasone or placebo beginning at 104-106 or 76-78 days' 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. The fetal tissues were harvested for water content determination 66 hours after the first injection of dexamethasone or placebo was given. In the multiple-course groups, the ewes received the same treatment (dexamethasone, n = 10, or placebo, n = 8), once a week for 5 weeks starting at 76-78 days' gestation. In these groups, the tissues were harvested 66 hours after the first the injection of the fifth and last treatment course. In both groups, tissues were harvested at 106-107 days' gestation. Tissue water content was determined by wet-to-dry weight ratio in brain (cerebral cortex, caudate nucleus, cerebellum, midbrain, and medulla) and somatic tissues (kidney, liver, muscle, and skin).

RESULTS

Water content in the brain regions (cerebellum and medulla) was lower (P <.05) in fetuses of dexamethasone-treated ewes than placebo-treated ewes after the multiple course but not the single course. Water content of somatic tissue was lower (P <.05) in fetuses of dexamethasone-treated ewes than placebo-treated ewes after the multiple courses, and in the liver after a single course.

CONCLUSION

Dexamethasone treatment of ewes at 70% of gestation results in decreased regional brain water content in the fetuses after multiple but not single treatment courses, in somatic tissues (kidney, liver, muscle, and skin) after multiple courses, and in the liver after a single course.

Effects of glucocorticoid treatment given in early or late gestation on growth and development in sheep

Antenatal corticosteroids are used to augment fetal lung maturity in human pregnancy. Dexamethasone (DEX) is also used to treat congenital adrenal hyperplasia of the fetus in early pregnancy. We previously reported effects of synthetic corticosteroids given to sheep in early or late gestation on pregnancy length and fetal cortisol levels and glucocorticoids alter plasma insulin-like growth factor (IGF) and insulin-like growth factor binding protein (IGFBP) concentrations in late pregnancy and reduce fetal weight. The effects of administering DEX in early pregnancy on fetal organ weights and betamethasone (BET) given in late gestation on weights of fetal brain regions or organ development have not been reported. We hypothesized that BET or DEX administration at either stage of pregnancy would have deleterious effects on fetal development and associated hormones. In early pregnancy, DEX was administered as four injections at 12-hourly intervals over 48 h commencing at 40–42 days of gestation (dG). There was no consistent effect on fetal weight, or individual fetal organ weights, except in females at 7 months postnatal age. When BET was administered at 104, 111 and 118 dG, the previously reported reduction in total fetal weight was associated with significant reductions in weights of fetal brain, cerebellum, heart, kidney and liver. Fetal plasma insulin, leptin and triiodothyronine were also reduced at different times in fetal and postnatal life. We conclude that at the amounts given, the sheep fetus is sensitive to maternal administration of synthetic glucocorticoid in late gestation, with effects on growth and metabolic hormones that may persist into postnatal life.

Repeat antenatal glucocorticoids for women at risk of preterm birth: a Cochrane Systematic Review

Administration of antenatal glucocorticoids to women at risk of preterm birth has major benefits for infants but the use of repeat dose(s) is controversial. We performed a systematic review of randomized trials, using standard Cochrane methodology, to assess the effectiveness and safety of 1 or more repeat doses given to women at risk of preterm birth 7 or more days after an initial course. Ten trials were included involving over 4730 women and 5700 infants. Treatment with repeat dose(s) compared with no repeat treatment reduced the risk of respiratory distress syndrome (risk ratio, 0.83; 95% confidence interval, 0.75-0.91) and serious neonatal morbidity (risk ratio, 0.84; 95% confidence interval, 0.75-0.94). At 2- to 3-year follow-up (4 trials, 4170 children), there was no evidence of either significant benefit or harm. Repeat doses of glucocorticoids should be considered in women at risk of preterm birth 7 or more days after an initial course, in view of the neonatal benefits.

Does in utero exposure to synthetic glucocorticoids influence birthweight, head circumference and birth length? A systematic review of current evidence in humans

Synthetic glucocorticoids are the mainstay treatment for stimulating lung maturation in threatened preterm delivery. Animal studies suggest that in utero exposure to glucocorticoids leads to a reduction in birth size. Smaller birthweight has been associated with higher risk of many chronic diseases. Therefore, the authors undertook a systematic review of human studies examining the association between synthetic glucocorticoid treatment and birth size. Medline, EMBASE, PubMed, Cochrane, Google scholar and Institute of Life Science databases were searched for studies published between 1978 and 2009 investigating the association between synthetic glucocorticoids and birthweight, head circumference, birth length and ponderal index. All studies controlling for gestational age were examined. Seventeen studies were included in the analysis. Nine out of 17 studies reported a reduction in birthweight (range 12-332 g), five of nine a reduction of head circumference (range 0.31-1.02 cm) and two of four a reduction of 0.8 cm in birth length. Despite methodological inconsistencies and limitations that impede clear conclusions, the evidence suggests an association between in utero exposure to synthetic glucocorticoids and reduced birth size.

Effect of prenatal glucocorticoid treatment on size at birth among infants born at term gestation

OBJECTIVE

To determine whether prenatal treatment with a single course of glucocorticoids (GCs) affects size at birth among full-term infants independent of fetal size before GC administration or exposure to preterm labor (PTL).

STUDY DESIGN

In all, 105 full-term infants were recruited into three study groups (30 GC treated; 60 controls matched for gestational age (GA) at birth and sex; and 15 PTL controls without GC exposure). Size of the infants was estimated before treatment using two-dimensional (2D) ultrasound and by direct measurement at birth.

RESULTS

Length, weight and head circumference at birth were smaller among GC-treated infants compared with matched controls (P's<0.01), although fetal size did not differ before treatment (P's>0.2). Exposure to PTL did not account for this effect.

CONCLUSIONS

Prenatal treatment with a single course of GCs was associated with a reduction in size at birth among infants born at term gestation. This effect cannot be explained by differences in fetal size before treatment or exposure to PTL.

A comparison of the effectiveness of single-dose vs multi-dose antenatal corticosteroids in pre-term neonates

The purpose of this study was to compare the outcome between exposure to single vs multiple courses of antenatal corticosteroids (AC) in pre-term births. The study involved 704 neonates delivered between 24-32 weeks. Maternal and perinatal outcome were compared between 294 (42%) neonates who received no AC; 257 (36%) who received single AC and 153 (22%) who received multiple AC. Any AC compared with no AC showed decreased composite neonatal morbidity (51% vs 62%, p = 0.004, odds ratio (OR) = 0.6), neonatal death (52% vs 62%, p = 0.004, OR = 0.6) and hyaline membrane disease (45% vs 57%, p = 0.002, OR = 0.6) with increased chorioamnionitis (17% vs 11%, p = 0.037, OR = 1.6) and pulmonary oedema (12% vs 1%, p = 0.0001, OR = 13). Multiple AC compared with single AC was associated with increased positive maternal cultures (44% vs 31%, p < or =0.005, OR = 1.8), small for gestational age infants (35% vs 21%, p = 0.001, OR = 2) and intraventricular haemorrhage (45% vs 34%, p <0.05, OR = 1.6). Multiple corticosteroid courses when compared with single corticosteroid course did not further reduce composite neonatal morbidity but increased the risk of positive maternal cultures and neonatal small for gestational age and intraventricular haemorrhage.

Antenatal dexamethasone treatment leads to changes in gene expression in a murine late placenta

Antenatal steroids like dexamethasone (DEX) are used to augment fetal lung maturity and there is a major concern that they impair fetal growth. If delivery is delayed after using antenatal DEX, placental function and hence fetal growth may be compromised even further. To investigate the effects of DEX on placental function, we treated 9 pregnant C57/BL6 mice with DEX and 9 pregnant mice were injected with saline to serve as controls. Placental gene expression was studied using microarrays in 3 pairs and other 6 pairs were used to confirm microarray results by semi-quantitative RT-PCR, real-time PCR, in situ hybridization, western blot analysis and Oligo ApopTaq assay. DEX-treated placentas were hydropic, friable, pale, and weighed less (80.0+/-15.1mg compared to 85.6.8+/-7.6mg, p=0.05) (n=62 placentas). Fetal weight was significantly reduced after DEX use (940+/-32mg compared to 1162+/-79mg, p=0.001) (n=62 fetuses). There was >99% similarity within and between the three gene chip data sets. DEX led to down-regulation of 1212 genes and up-regulation of 1382 genes. RT-PCR studies showed that DEX caused a decrease in expression of genes involved in cell division such as cyclins A2, B1, D2, cdk 2, cdk 4 and M-phase protein kinase along with growth-promoting genes such as EGF-R, BMP4 and IGFBP3. Oligo ApopTaq assay and western blot studies showed that DEX-treatment increased apoptosis of trophoblast cells. DEX-treatment led to up-regulation of aquaporin 5 and tryptophan hydroxylase genes as confirmed by real-time PCR, and in situ hybridization studies. Thus antenatal DEX treatment led to a reduction in placental and fetal weight, and this effect was associated with a decreased expression of several growth-promoting genes and increased apoptosis of trophoblast cells.

Multiple courses of antenatal steroids

The benefits and risks of multiple courses of antenatal steroids (ANS) are still unresolved issues. This was a prospective cohort study in a level III neonatal unit. Preterm babies < or = 35 wk gestation were included. Malformations, chronic maternal steroid intake, exchange transfusions prior to cortisol sampling and incomplete ANS courses were exclusion criteria. Subjects were classified into: No course (Group 0), 1 course (group 1), 2 courses (Group 2), > 2 courses (Group 3) of antenatal dexamethasone. The key outcome was adrenal function assessed by basal and post-ACTH cortisol on day 3. Other outcomes were neonatal morbidity, mortality, growth parameters at birth, long term growth and neuro-development. Of 210 eligible babies, 124 were enrolled. 38, 51, 10 and 25 babies belonged to groups 0, 1, 2 and 3 respectively. Basal and post-ACTH serum cortisol did not show any significant difference between groups (p=0.5 and p=0.9 respectively). Incidence of severe HMD requiring ventilation was significantly lower (p=0.02) in multiple course group (combined groups 2 and 3) compared to single course group. There were no differences in other neonatal morbidity, birth OFC and weight between single and multiple ANS groups. Follow up data at a mean age of 22 mth was available in 59 subjects (69%) belonging to groups 1-3. No differences were noted in the proportion of patients with abnormal neurological examination (p=0.1), abnormal PDI (p=0.9), abnormal MDI (p=0.9) and physical growth between multiple and single course groups. Multiple courses of antenatal dexamethasone resulted in a significant decrease in severe forms of RDS and they did not cause adrenal suppression, decreased growth or impaired neuro-development.

[Antenatal exposure to corticosteroids for fetal lung maturation and its repercussion on weight, length and head circumference in the newborn infant]

BACKGROUND AND OBJECTIVE

To study the effects of antenatal corticosteroids treatment to promote fetal lung maturation, on fetal growth, depending on the number of the courses administered.

PATIENTS AND METHOD

The study was based on data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), analysing a sample of 29,557 singleton liveborn infants without congenital defects. An stratified analysis by gestational age was performed to compare the weight, length and head circumference at birth, in the exposed and unexposed infants to dexamethasone/betamethasone. To control confounding factors (year of birth, maternal age, gestational age, parity, maternal smoking and/or alcohol consumption, gestational diabetes, non-gestational diabetes and other maternal chronic diseases) we used a general linear model with random effects, being the randomised variable the place of birth.

RESULTS

The exposure to more than one course of antenatal corticosteroids resulted in a significant reduction of birth weight, length and head circumference in singleton preterm infants. The birth weight decreased by 22% (p < 0.0001), the length 5% (p = 0.002) and the head circumference 6% (p = 0.0005). The treatment with only one course reduced also significantly the weight and length but not the head circumference. In addition, we observed a significant interaction between the treatment and gestational age at birth indicating that the effect of corticosteroids is stronger in the most premature babies.

CONCLUSIONS

In this retrospective analysis, the antenatal exposure to corticosteroids to promote fetal maturation is associated with diminished weight, length and head circumference in the premature newborn infant. This negative effect was greater in those premature babies exposed to multiple courses.

Effects of antenatal magnesium sulfate and corticosteroid therapy on sleep states of preterm infants

This exploratory longitudinal study was designed to compare the neonatal illness severity, sleep-wake, and respiratory sleep behaviors of preterm infants whose mothers received prenatal corticosteroids and/or magnesium sulfate (MgSO4) with those of infants whose mothers did not receive these medications. The 134 infants were divided into four groups: those whose mothers received MgSO4 only, those who received steroids only, those who received both MgSO4 and steroids, and those who received neither. The groups did not differ on infant characteristics or illness severity. Infants exposed to MgSO4 had more active sleep without rapid eye movement, indicating poorly organized active sleep. The MgSO4 -only group had higher quiet sleep regularity scores and fewer state changes. These findings suggest that fetal exposure to MgSO4 may subtly affect the central nervous system.

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.

Projected benefits of universal or scheduled antepartum corticosteroids to prevent neonatal morbidity: a decision analysis

OBJECTIVE

The purpose of this study was to compare strategies of corticosteroid administration for the prevention of neonatal morbidity and death.

STUDY DESIGN

A Markov decision model compared 3 strategies of antepartum corticosteroid administration: (1) to all pregnant women (universal), (2) to all pregnant women with a previous preterm delivery (high risk), and (3) to women who had preterm labor symptoms that placed them at risk for delivery within 7 days (current). A second model with addition of a "rescue" arm to capture women who remained undelivered was also created.

RESULTS

Compared with the current strategy, the universal strategy would result in roughly 1000 fewer cases of respiratory distress syndrome and > 3 million more women would receive corticosteroids annually. The addition of a rescue arm further reduces morbidity and mortality rates.

CONCLUSION

A universal strategy of corticosteroid administration confers potential benefit for the prevention neonatal morbidity or death over the current strategy but requires that a large number of women be treated.

Antenatal corticosteroid therapy in premature infants

OBJECTIVE

The objective was to examine the effect of antenatal corticosteroid treatment on premature infants, with special attention to any possible adverse effects on neonatal outcome.

METHODS

A retrospective chart review of all singleton and multiple pregnancies delivered in our perinatal center between 1991 and 1999, who had a birth weight of < or =1,500 g and who were subsequently admitted to our neonatal intensive care unit. Three hundred and sixty-five infants were included in the study and divided into two groups. One group had a gestational age below 28 weeks (< or =196 days) and one group was 28 weeks (>196 days) onward.

RESULTS

Antenatal corticosteroid therapy reduced the duration of mechanical ventilation, the need for supplementary oxygen, and the need for exogenous surfactant in neonates born at >196 days's gestation (p<0.05). Corticosteroid treatment seemed to benefit the respiratory distress syndrome (RDS; p=0.051) in this group. There were less cases of necrotizing enterocolitis and neonatal death in the group with corticosteroid treatment (p<0.05). Before 28 weeks' gestation, all parameters that were examined (e.g., duration of mechanical ventilation, need for supplemental oxygen, need for exogenous surfactant, RDS) showed no significant differences between those pregnancies pre-treated with corticosteroids or those not treated with corticosteroids. There was no adverse effect of corticosteroids on chorioamnionitis and early onset sepsis in pregnancies with a premature rupture of the membranes. Repeated corticosteroid treatment had no effect on birth weight, but did not improve neonatal outcome either. The interval between last corticosteroid treatment and delivery had no influence on RDS. There was no effect of corticosteroids on periventricular leukomalacia and intraventricular hemorrhage. Regression analysis showed a higher risk of severe RDS in multiple gestations.

CONCLUSION

Antenatal betamethasone treatment reduces perinatal morbidity and mortality after 28 weeks' gestation. We found no adverse effects and also no benefit of repetitive corticosteroid treatment. The interval between last corticosteroid treatment and delivery did not influence the incidence of RDS. Dose, timing, and rate of antenatal corticosteroids should be reconsidered in multiple gestations.

Use and misuse of corticosteroids

Corticosteroids are amongst the most common drugs used in clinical medicine. Prudent management of patients is essential to avoid steroid-induced complications.

Antenatal corticosteroids for fetal maturation in women at risk for preterm delivery

The available data unambiguously support the beneficial, short-term fetal effects of antenatal corticosteroids in women at risk for preterm delivery. There are still several incompletely addressed questions, including the use of corticosteroids in women with preterm premature rupture of membranes, the optimal corticosteroid preparation to be used, and the impact of repeated dosing. These issues are discussed in this review from the perspective of recent scientific evidence on the mechanisms responsible for positive short-term effects on survival and possible harmful long-term effects.

Repeated courses of antenatal corticosteroids: is it justified?

The benefits of a single course of antenatal corticosteroids on neonatal outcomes are well established. There is, however, much controversy about how long this treatment should continue, and whether repeated courses should be administered if the women remain at risk for preterm delivery 7 days after the initial therapy. This review aims to discuss current evidence on the effectiveness and safety of repeated courses of antenatal corticosteroids.

Steroids

Corticosteroids are considered to be essential stress hormones. They are secreted together with adrenocorticotropic hormone (ACTH) in response to the pulsatile secretion of corticotropin-releasing hormone from the paraventricular nucleus of the hypothalamus. Changes in pulse amplitude are responsible for the diurnal rhythm in circulating ACTH and cortisol levels. Steroid levels increase immediately after injury, pain, fever, and hypovolemia in response to the stimulation of corticotropin-releasing hormone secretion by various cytokines. The increase in steroid levels is typically proportional to the magnitude of stress, with serum cortisol values being highest in moribund patients and shortly before death. With severe and prolonged stress, steroid levels are increased for weeks to months and may be associated with hypertrophy of the adrenal cortex. Cortisol acts in concert with catecholamines to maintain the vascular tone, endothelial integrity, vascular permeability, and the distribution of total body water within the vascular compartment. It also potentiates the vasoconstrictor effects of catecholamines. Cortisol helps to stimulate lipolysis, inhibit protein synthesis, facilitate amino acid mobilization from muscle, induce the enzymes of gluconeogenesis, enhance secretion of glucagon, inhibit insulin secretion, and stimulate conversion of lactic acid to glycogen. Because of their anti-inflammatory properties, steroids have been proposed as therapeutic adjuvants in systemic inflammation and may protect the host against overshooting defense reactions by reducing the migration of leukocytes to the inflammatory sites and the incidence of neutrophil-mediated tissue injury and organ dysfunction.

Preterm labour

Studies in the past year have clarified the roles of inflammatory mediators in preterm labour. Exploration of possible genetic predisposition is just beginning. Ultrasound measurement of cervical length has the potential to predict women at risk of preterm delivery several weeks before it occurs. Biochemical testing such as fetal fibronectin can possibly increase its predictive value and differentiate true preterm labour from more innocent preterm contractions. The use of antibiotics for preterm premature rupture of membranes has been clarified with the ORACLE I trial, which shows health benefits for the neonate with the use of erythromycin, whereas antibiotics do not seem to play a beneficial role in spontaneous preterm labour without evidence of clinical infection. There have been further studies suggesting that agents other than beta-agonists are preferable for acute tocolysis and that repeated doses of corticosteroids should be used with caution.

Perinatal glucocorticoid therapy and neurodevelopmental outcome: an epidemiologic perspective

A relatively brief course of antenatal glucocorticoids (ACS), given to reduce the severity of respiratory distress syndrome in preterm infants, improves survival and appears to protect against brain damage. In clinical trials as well as observational studies, ACS have been associated with a decreased risk of intraventricular haemorrhage and cerebral palsy. In observational studies a decreased risk of white-matter damage, identified with cranial ultrasound, has been observed. There is some evidence, from observational studies, that repeated courses of ACS (typically given at weekly intervals) can reduce the rate of fetal head growth, and experiments in animals provide further support for this possibility. In contrast to the effects of a brief course of ACS, postnatal glucocorticoids (PCS), given to preterm infants to reduce the severity of chronic lung disease have been associated with an increased risk of neurologic impairment. Available evidence suggests that PCS does not improve survival. Further study is needed of the neurodevelopmental consequences of both multiple courses of ACS, as well as PCS.