Prenatal corticosteroids--early gain, long-term questions

Pulmonary function and outcomes in infants randomized to a rescue course of antenatal steroids

BACKGROUND/OBJECTIVE

Our objective was to obtain follow-up pulmonary function testing and assessment of clinical respiratory outcomes, at 1-2 years, in preterm infants whose mothers were randomized to a single rescue course of antenatal steroids (AS) versus placebo.

METHODS

Follow-up of a randomized, double-blinded trial. In the original trial pregnant women ≥14 days after initial course of AS were randomized to rescue AS or placebo. Pulmonary function testing and a standardized respiratory questionnaire were obtained at 1-2 years of corrected age. Respiratory compliance (Crs) was measured with the single-breath occlusion and functional residual capacity (FRC) with the nitrogen washout method. Analysis was by intention-to-treat.

RESULTS

A total of 96 (87%) of available survivors were administered a respiratory questionnaire. Seventy-seven percent of available patients had pulmonary function testing performed. There was no significant difference between groups in incidence of wheezing, asthma, respiratory syncytial virus infection, respiratory readmissions, use of bronchodilators or other medications, or in measurements of pulmonary function. There was also no significant difference in corrected age at study, race, gender, or length at the time of pulmonary function testing. Infants in the rescue group had a comparable mean FRC (249.4 mL vs 246.2 mL; adjusted 95%CI for difference -15.45, 38.20; P = 0.37) versus placebo. There were no differences in tidal volume or Crs.

CONCLUSION

A rescue course of AS significantly increases Crs within 72 h of age and decreases oxygen need in newborn infants, without an adverse impact on pulmonary function or clinical respiratory outcomes at 1-2 years of age [NCT00669383].

SOMANZ guidelines for the management of hypertensive disorders of pregnancy 2014

This guideline is an evidence based, practical clinical approach to the management of Hypertensive Disorders of Pregnancy. Since the previous SOMANZ guideline published in 2008, there has been significant international progress towards harmonisation of definitions in relation to both the diagnosis and management of preeclampsia and gestational hypertension. This reflects increasing knowledge of the pathophysiology of these conditions, as well as their clinical manifestations. In addition, the guideline includes the management of chronic hypertension in pregnancy, an approach to screening, advice regarding prevention of hypertensive disorders of pregnancy, and discussion of recurrence risks and long term risk to maternal health. The literature reviewed included the previous SOMANZ Hypertensive Disorders of Pregnancy guideline from 2008 and its reference list, plus all other published National and International Guidelines on this subject. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT), National Institute for Health and Care Excellence (NICE) Evidence Search, and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2007 and March, 2014.

Antenatal corticosteroids and perinatal outcomes in infants born at 23-25 weeks of gestation

OBJECTIVES

To evaluate the perinatal results of infants born between 23 and 25.6 weeks of gestation.

METHODS

Medical charts of all women giving birth prematurely (23-25.6 w) from January 2005 to December 2011 were retrospectively reviewed. Cases of malformed infants or deliveries elsewhere were excluded.

RESULTS

198 infants were included. Chorioamnionitis occurred in 86 (43.4%) of the whole group: 26 (86.7%) in the 23-week; 35 (53.8%) in the 24-week and 25 (24.3%) in the 25-week groups. Foetal maturation with antenatal corticosteroids was complete in 119 cases (60.1%): 4 (13.3%) in the 23-week; 35 (53.8%) in the 24-week and 80 (77.7%) in the 25-week groups. Foetal death at birth occurred in 22 cases (11%) and 61 newborns (30.8%) died in the neonatal period. Of the 106 survivors with 2 years complete follow-up, 45 infants (42.4%) did not present sequelae; 16 infants (15.1%) had severe sequelae. A 66.6% (4) of infants born at 23 weeks of gestation did not present sequelae compared with a 32.3% (11) at 24 weeks and 45.4% (30) at 25 weeks.

CONCLUSIONS

The chorioamnionitis rate was higher when gestational age was lower. The foetal maturation rate was higher when gestational age was higher. A low severe sequelae rate was observed in the whole series, particularly in the 23-week group where the rate was lower than expected; however, these results could have been influenced by the small size of the 23-week group.

Maternal treatment with glucocorticoids modulates gap junction protein expression in the ovine fetal brain

Gap junctions facilitate intercellular communication and are important in brain development. Connexins (Cx) comprise a transmembrane protein family that forms gap junctions. Cx-32 is expressed in oligodendrocytes and neurons, Cx-36 in neurons, and Cx-43 in astrocytes. Although single antenatal steroid courses are recommended for fetal lung maturation, multiple courses can be given to women at recurrent risk for premature delivery. We examined the effects of single and multiple glucocorticoid courses on Cx-32, Cx-36, and Cx-43 protein expressions in the fetal cerebral cortex, cerebellum, and spinal cord, and differences in Cx expression among brain regions under basal conditions. In the single-course groups, the ewes received dexamethasone (6 mg) or placebo as four intramuscular injections every 12h over 48 h. In the multiple-course groups, the ewes received the same treatment, once a week for 5 weeks starting at 76-78 days of gestation. Cx were measured by Western immunoblot on brain samples from 105 to 108-day gestation fetuses. A single dexamethasone course was associated with increases (P<0.05) in cerebral cortical and spinal cord Cx-36 and Cx-43 and multiple courses with increases in cerebellar and spinal cord Cx-36, and cerebral cortical and cerebellar Cx-43. Cx-32 did not change. Cx-32 was higher in the cerebellum than cerebral cortex and spinal cord, Cx-36 higher in the spinal cord than cerebellum, and Cx-43 higher in the cerebellum and spinal cord than cerebral cortex during basal conditions. In conclusion, maternal glucocorticoid therapy increases specific Cx, responses to different maternal courses vary among Cx and brain regions, and Cx expression differs among brain regions under basal conditions. Maternal treatment with glucocorticoids differentially modulates Cx in the fetal brain.

Association of antenatal corticosteroids with mortality and neurodevelopmental outcomes among infants born at 22 to 25 weeks' gestation

CONTEXT

Current guidelines, initially published in 1995, recommend antenatal corticosteroids for mothers with preterm labor from 24 to 34 weeks' gestational age, but not before 24 weeks due to lack of data. However, many infants born before 24 weeks' gestation are provided intensive care.

OBJECTIVE

To determine if use of antenatal corticosteroids is associated with improvement in major outcomes for infants born at 22 and 23 weeks' gestation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study of data collected prospectively on inborn infants with a birth weight between 401 g and 1000 g (N = 10,541) born at 22 to 25 weeks' gestation between January 1, 1993, and December 31, 2009, at 23 academic perinatal centers in the United States. Certified examiners unaware of exposure to antenatal corticosteroids performed follow-up examinations on 4924 (86.5%) of the infants born between 1993 and 2008 who survived to 18 to 22 months. Logistic regression models generated adjusted odds ratios (AORs), controlling for maternal and neonatal variables.

MAIN OUTCOME MEASURES

Mortality and neurodevelopmental impairment at 18 to 22 months' corrected age.

RESULTS

Death or neurodevelopmental impairment at 18 to 22 months was significantly lower for infants who had been exposed to antenatal corticosteroids and were born at 23 weeks' gestation (83.4% with exposure to antenatal corticosteroids vs 90.5% without exposure; AOR, 0.58 [95% CI, 0.42-0.80]), at 24 weeks' gestation (68.4% with exposure to antenatal corticosteroids vs 80.3% without exposure; AOR, 0.62 [95% CI, 0.49-0.78]), and at 25 weeks' gestation (52.7% with exposure to antenatal corticosteroids vs 67.9% without exposure; AOR, 0.61 [95% CI, 0.50-0.74]) but not in those infants born at 22 weeks' gestation (90.2% with exposure to antenatal corticosteroids vs 93.1% without exposure; AOR, 0.80 [95% CI, 0.29-2.21]). If the mothers had received antenatal corticosteroids, the following events occurred significantly less in infants born at 23, 24, and 25 weeks' gestation: death by 18 to 22 months; hospital death; death, intraventricular hemorrhage, or periventricular leukomalacia; and death or necrotizing enterocolitis. For infants born at 22 weeks' gestation, the only outcome that occurred significantly less was death or necrotizing enterocolitis (73.5% with exposure to antenatal corticosteroids vs 84.5% without exposure; AOR, 0.54 [95% CI, 0.30-0.97]).

CONCLUSION

Among infants born at 23 to 25 weeks' gestation, antenatal exposure to corticosteroids compared with nonexposure was associated with a lower rate of death or neurodevelopmental impairment at 18 to 22 months.

Respiratory compliance in preterm infants after a single rescue course of antenatal steroids: a randomized controlled trial

OBJECTIVE

To compare respiratory compliance and functional residual capacity in infants randomized to a rescue course of antenatal steroids vs placebo.

STUDY DESIGN

Randomized, double-blinded trial. Pregnant women > or =14 days after initial antenatal steroids were randomized to rescue antenatal steroids or placebo. The primary outcomes were measurements of respiratory compliance and functional residual capacity. This study is registered with clinicaltrials.gov (NCT00669383).

RESULTS

Forty-four mothers (56 infants) received rescue antenatal steroids and 41 mothers (57 infants) received placebo. There was no significant difference in birthweight, or head circumference. Infants in the rescue group had an increased respiratory compliance (1.21 vs 1.01 mL/cm H(2)O/kg; adjusted 95% confidence interval, 0.01-0.49; P = .0433) compared with placebo. 13% in the rescue vs 29% in the placebo group required > or =30% oxygen (P < .05). Patients delivered at < or =34 weeks had greater pulmonary benefits.

CONCLUSION

Infants randomized to rescue antenatal steroids have a significantly increased respiratory compliance compared with placebo.

Maternal glucocorticoid exposure alters tight junction protein expression in the brain of fetal sheep

We examined the expression of tight junction (TJ) proteins in the cerebral cortex, cerebellum, and spinal cord of fetuses after maternal treatment with single and multiple courses of dexamethasone. Ewes received either single courses of four 6-mg dexamethasone or placebo injections every 12 h for 48 h between 104 and 107 days or the same treatment once a week between 76-78 and 104-107 days of gestation. TJ protein expression was determined by Western immunoblot analysis on tissue harvested at 105-108 days of gestation. Blood-brain barrier permeability has been previously quantified with the blood-to-brain transfer constant (K(i)) with alpha-aminoisobutyric acid (39). After a single course of dexamethasone, claudin-5 increased (P < 0.05) in the cerebral cortex, occludin and claudin-1 increased in the cerebellum, and occludin increased in the spinal cord. After multiple dexamethasone courses, occludin and zonula occludens (ZO)-1 increased in the cerebral cortex, and occludin and claudin-1 increased in the cerebellum. Junctional adhesion molecule-A and ZO-2 expressions did not change. Linear regression comparing K(i) to TJ proteins showed inverse correlations with claudin-1 and claudin-5 in the cerebral cortex after a single course and ZO-2 in the spinal cord after multiple courses and direct correlations with ZO-1 in the cerebellum and spinal cord after multiple courses. We conclude that maternal glucocorticoid treatment increases the expression of specific TJ proteins in vivo, patterns of TJ protein expression vary after exposure to single and multiple glucocorticoid courses, and decreases in blood-brain barrier permeability are associated with increases in claudin-1, claudin-5, and ZO-2 expression and decreases in ZO-1 expression. In utero glucocorticoid exposure alters the molecular composition of the barrier and affects fetal blood-brain barrier function.

[Repeat doses of prenatal corticosteroids for women at risk of preterm birth: a difficult consensus]

A single course of antenatal corticosteroids in women at risk of preterm delivery reduces the risk of neonatal mortality and morbidity. Recent experimental and clinical studies have stated early, medium and long term consequences of single or repeated courses of antenatal corticosteroids. Betamethasone and dexamethasone are the two molecules usually used. Benefits are observed until the first 24 hours after the first injection. Single-course corticosteroids are not effective in babies born more than 7 days after initial treatment. Benefits of corticosteroids were evaluated between 22 and 35 weeks of gestation. Antenatal exposure to single-course betamethasone might result in disruption on glucose metabolism in adult offspring. Weekly courses of prenatal corticosteroids therapy are not recommended. Repeat prenatal corticosteroids given to women at continuing risk of preterm birth 7 or more days after an initial course reduced the inherent respiratory complications of prematurity and improved health outcomes of preterm infants. However, adverse outcomes have been reported concerning cognitive development. Although repeat course may have short term benefits, whether there are effects on health into childhood and beyond must await later assessment. Long term data are needed to recommend repeated courses.

The HELLP syndrome: clinical issues and management. A Review

BACKGROUND

The HELLP syndrome is a serious complication in pregnancy characterized by haemolysis, elevated liver enzymes and low platelet count occurring in 0.5 to 0.9% of all pregnancies and in 10-20% of cases with severe preeclampsia. The present review highlights occurrence, diagnosis, complications, surveillance, corticosteroid treatment, mode of delivery and risk of recurrence.

METHODS

Clinical reports and reviews published between 2000 and 2008 were screened using Pub Med and Cochrane databases.

RESULTS AND CONCLUSION

About 70% of the cases develop before delivery, the majority between the 27th and 37th gestational weeks; the remainder within 48 hours after delivery. The HELLP syndrome may be complete or incomplete. In the Tennessee Classification System diagnostic criteria for HELLP are haemolysis with increased LDH (> 600 U/L), AST (>or= 70 U/L), and platelets < 100 x 10(9)/L. The Mississippi Triple-class HELLP System further classifies the disorder by the nadir platelet counts. The syndrome is a progressive condition and serious complications are frequent. Conservative treatment (>or= 48 hours) is controversial but may be considered in selected cases < 34 weeks' gestation. Delivery is indicated if the HELLP syndrome occurs after the 34th gestational week or the foetal and/or maternal conditions deteriorate. Vaginal delivery is preferable. If the cervix is unfavourable, it is reasonable to induce cervical ripening and then labour. In gestational ages between 24 and 34 weeks most authors prefer a single course of corticosteroid therapy for foetal lung maturation, either 2 doses of 12 mg betamethasone 24 hours apart or 6 mg or dexamethasone 12 hours apart before delivery. Standard corticosteroid treatment is, however, of uncertain clinical value in the maternal HELLP syndrome. High-dose treatment and repeated doses should be avoided for fear of long-term adverse effects on the foetal brain. Before 34 weeks' gestation, delivery should be performed if the maternal condition worsens or signs of intrauterine foetal distress occur. Blood pressure should be kept below 155/105 mmHg. Close surveillance of the mother should be continued for at least 48 hours after delivery.

Na+, K+-ATPase activity and subunit isoform protein abundance: effects of antenatal glucocorticoids in the frontal cerebral cortex and renal cortex of ovine fetuses

We examined the effects of single and multiple maternal glucocorticoid courses on cerebral cortical (CC) and renal cortical (RC) Na(+),K(+)-ATPase activity and protein isoform abundance in fetal sheep. Ewes received four dexamethasone or placebo injections in the single course (SC) groups, and the same treatment once a week for five-weeks in the multiple course (MC) groups. CC Na(+),K(+)-ATPase a(2)-abundance was higher (P<0.05) and beta(2)-abundance lower in the SC dexamethasone than placebo group, but Na(+),K(+)-ATPase activity did not change. CC Na(+),K(+)-ATPase activity, a(1)-, beta(1) -, and beta(2)-abundance were lower in the MC dexamethasone than placebo group, but a(2)- and a(3)-abundance did not change. Both dexamethasone courses did not affect CC cell number. RC Na(+),K(+)-ATPase activity, a(1)- and beta(1) -abundance were higher in the MC dexamethasone than placebo group, but did not change in the SC dexamethasone group. We conclude MC, but not a SC of dexamethasone, affect fetal cerebral and renal Na(+),K(+)-ATPase, and MC result in differential effects on Na(+),K(+)-ATPase in these organs.