Prenatal Corticosteroid Therapy Research Articles

The need for assisted ventilation corroborates the effectiveness of antenatal corticosteroid therapy in preventing premature lamb mortality

In premature births, deficiency and/or inactivation of surfactant and incomplete development of lung occur, leading to pulmonary complications and greater need for ventilatory interventions. Prenatal corticosteroid therapy is used to improve neonatal lung function and, thus, may reduce mortality and lower incidence and severity of lung injury. Therefore, this study aimed to assess the need for ventilatory support in preterm lambs subjected or not to prenatal betamethasone treatment, and to evaluate the effectiveness on neonatal survival. Lambing was induced and 13 premature lambs were assigned to Corticosteroid Group (n = 8; lambs from ewes subjected previously to 0.5 mg/kg betamethasone, IM, at 133 days of pregnancy) and Control Group (n = 5; non-treated lambs). Lambs were evaluated for vitality, neurologic reflexes, vital functions and birth weight. Three ventilatory modalities were preconized for critical lambs, according to specific criteria: mask oxygen therapy, self-inflating bag with tracheal tube and mechanical ventilation. Non-treated lambs had lower vitality score, muscle tonus and respiratory rate compared to Corticosteroid Group. Ventilatory support was needed for 3 Control lambs and only 1 Corticosteroid neonate. Corticosteroid lamb required significant less time-frame between birth and onset of ventilatory assistance and remained under ventilation for a shorter time. Percentage of ventilated non-treated lambs correlated negatively with birth weight, muscle tone, heart and respiratory rate. In conclusion, antenatal betamethasone treatment reduces the need for ventilatory assistance in premature lambs. Additionally, mortality is low when a protocol for inducing pulmonary maturity (maternal corticosteroid therapy) and/or ventilatory interventions are employed, ensuring the survival of premature lambs.

Influence of prenatal corticosteroid therapy on neonatal vitality and utility as a labor-inducing agent in Santa Inês ewes.

Since the 1970s, maternal corticosteroid therapy has been used successfully to induce labor. This allows for better monitoring of parturients and provision of first aid to neonates, improving neonatal viability, as this treatment induces maturation in a variety of fetal tissues, thereby reducing morbidity and mortality. Although the effects of corticosteroids are well known, few studies have investigated the influence of this therapy in Santa Inês sheep. This study aimed to evaluate the efficacy of dexamethasone at two doses (8 and 16 mg) to induce lambing in Santa Inês ewes at 145 days of gestation and assess its effects on neonatal vitality. For this study, 58 ewes raised in an extensive system were investigated. Pregnancy was confirmed after artificial insemination at a set time or after controlled mounting. Ewes were separated into three groups: an untreated control group (G1: 0 mg) and groups treated with two doses of dexamethasone (G2: 8 mg and G3: 16 mg). In total, 79 lambs were born. Their vitality was assessed based on their Apgar score, weight, temperature, and postnatal behavior. SAS v9.1.3 (SAS Institute, Cary, NC) was used to analyze data, considering a 5% significance level for all analyses. The births in the induced groups occurred 48.4 ± 22.1 h after induction, while the ewes that underwent non-induced labor gave birth 131.96 ± 41.9 h after placebo application (p < 0.05), confirming the efficacy of dexamethasone to induce and synchronize labor. The induced and non-induced neonates had similar Apgar scores, temperatures, weights, and postnatal behavioral parameters (p > 0.05). This study showed that inducing labor in Santa Inês ewes at 145 days of gestation with a full (16 mg) or half dose (8 mg) of dexamethasone is an effective technique and does not compromise neonate vitality.

Use of Antenatal Steroids Treatment to Reduce Neonatal Respiratory Morbidity Prior to Cesarean Section in Preterm Birth

Objective: To compare the rate of neonatal respiratory morbidity between individuals who received prenatal corticosteroids before to caesarean delivery at 34-37 weeks and those who did not. Patients and Methods: A total of 150 patients who presented with preterm labour having gestational age between 34-37 weeks and no neonatal congenital anomaly on anomaly scan were recruited from June-2021 to December-2021 from the gynecology unit of Nishtar Hospital Multan. Women divided into two groups. Group A; in these patients intramuscular dexamethasone (12 mg) was given in 2 doses 12 hours apart. Group B (Control group): in these patients no drug was given as a prophylaxis again neonatal respiratory morbidity. After delivery, each neonate was monitored for 24 hours after delivery to determine the respiratory morbidity. Results: Mean age of patients was 31.19±5.02 years. Mean gestational age was 35.66±1.10 weeks with range of 34-37 weeks. There were 78 (52.0%) patients who were prima-gravida and remaining 72 (48.0%) were Multi-gravida. There were 14 (9.3%) patients who were having previous abortion history. Respiratory morbidity was diagnosed in only 2 (2.7%) neonates in group A and in 07 (9.3%) neonates in group B (p-value 0.08) Conclusion: Prenatal corticosteroid therapy prior to elective caesarean section at 34–37 weeks of gestation significantly reduces neonatal respiratory morbidity. Keywords: Antenatal corticosteroids, Elective cesarean section, Neonatal respiratory morbidity.

Prenatal therapy with magnesium sulphate and intestinal obstruction due to meconium in preterm newborns

IntroductionMagnesium sulphate (MgSO4) therapy has shown to be useful as a neurological protector in the preterm newborn below 32 weeks of gestation. The most documented adverse effect is cardiorespiratory failure, whereas its relationship with meconium obstruction is controversial. The main objective of this study was to analyse the possible association between prenatal MgSO4 therapy and meconium obstruction. Patients and methodsAn analytical retrospective study was conducted on <32 weeks preterm babies admitted to a tertiary-level hospital (January 2016–December 2017). Epidemiological, prenatal and postnatal data on the outcomes were obtained, analysed and compared in both groups (exposed to MgSO4 and not exposed). ResultsThe study included 201 patients (146 exposed and 55 non-exposed). There were no significant differences in the mean gestational age (28.4 ± 2.2 vs. 28.7 ± 2.8 weeks, respectively), or in the rest of epidemiological and perinatal variables. Prenatal corticosteroid therapy was more frequent in the MgSO4 group (75.9 vs. 53.7%; p = .002), and in the non-exposed group there were more multiple pregnancies (52.7 vs. 36.6%; p = .027), and female gender (56.4 vs. 37%; p = .013). There were no statistically significant differences in the presence of meconium obstruction (75.9% in exposed vs. 67.3% in non-exposed; p = .23), although repeated rectal stimulation was more frequent in the exposed group (43.2 vs. 27.9%; p = .08). Furthermore, there were no significant differences in the main cardiorespiratory variables: 1-min Apgar score (6.2 in MgSO4− exposed vs. 5.6 in non-exposed; p = .75), 5-min Apgar score (7.9 vs. 7.6; p = .31), advanced newborn resuscitation (26 vs. 31.5%; p = .44), maximum FiO2 (45.5 vs. 48; p = .58), and initial inotropic requirements (10.3 vs. 20.8%; p = .55). ConclusionsThis study found no correlations between MgSO4 therapy and meconium obstruction or cardiorespiratory failure.

A new individualized prognostic approach to the management of women at risk of extreme preterm birth in France: Effect on neonatal outcome

IntroductionAfter discussion with the parents, periviable infants can receive either active treatment or palliative care. The rate of active treatment in France is lower than in other developed countries, as is the survival rate of infants in this gestational age range. This study's main objective was to assess the effect of a standardized perinatal management protocol (EXPRIM) on the neonatal outcome of children born before 27 weeks of gestation. MethodsA before-and-after study was conducted in the two level-3 hospitals of the Risks and Pregnancy DHU to compare two 16-month periods. The EXPRIM protocol was based on routine administration of prenatal corticosteroid therapy and a scheduled combined obstetric-pediatric group prenatal prognostic evaluation, not based solely on gestational age. The study included all births between 22 weeks and 26 weeks+6 days of gestation, except in utero deaths diagnosed at admission and medical terminations of pregnancy for fetal malformation, both excluded. The principal endpoint was survival without severe neonatal morbidity. ResultsThe study included 267 women: 116 (128 newborns) in period 1 and 151 (172 newborns) in period 2. The median gestational age at admission to the maternity unit was 2.5 days younger in period 2, and the number of women admitted at 22–23 weeks doubled in period 2 (59 vs 29, respectively). Overall, the rates of live births, NICU transfer, and survival without severe morbidity were similar during the two periods. More infants were liveborn between 22 and 24 weeks in period 2 (66 vs 43). Of all newborns transferred to the NICU, 26 (29%) survived without severe morbidity in period 1 and 46 (39%) in period 2. After multivariate analysis, survival without severe morbidity did not differ significantly. ConclusionImplementation of the EXPRIM protocol led to active treatment of more mothers and their children at the border of viability, and increased the number of children who survived without severe morbidity even if, overall, there was no statistically significant difference in percentage.

Terapia prenatal con sulfato de magnesio y obstrucción intestinal por meconio en recién nacidos pretérmino

IntroductionMagnesium sulphate (MgSO4) therapy has shown to be useful as a neurological protector in the preterm newborn below 32 weeks of gestation. The most documented adverse effect is cardiorespiratory failure, whereas its relationship with meconium obstruction is controversial.The main objective of this study was to analyse the possible association between prenatal MgSO4 therapy and meconium obstruction. Patients and methodsAn analytical retrospective study was conducted on < 32 weeks preterm babies admitted to a tertiary-level hospital (January 2016-December 2017). Epidemiological, prenatal and postnatal data on the outcomes were obtained, analysed and compared in both groups (exposed to MgSO4 and not exposed). ResultsThe study included 201 patients (146 exposed and 55 non-exposed). There were no significant differences in the mean gestational age (28.4 ± 2.2 vs. 28.7 ± 2.8 weeks, respectively), or in the rest of epidemiological and perinatal variables. Prenatal corticosteroid therapy was more frequent in the MgSO4 group (75.9 vs. 53.7%; p = .002), and in the non-exposed group there were more multiple pregnancies (52.7 vs. 36.6%; p = .027), and female gender (56.4 vs. 37%; p = .013). There were no statistically significant differences in the presence of meconium obstruction (75.9% in exposed vs. 67.3% in non-exposed; p = .23), although repeated rectal stimulation was more frequent in the exposed group (43.2 vs. 27.9%; p = .08). Furthermore, there were no significant differences in the main cardiorespiratory variables: 1-minute Apgar score (6.2 in MgSO4- exposed vs. 5.6 in non-exposed; p = .75), 5-minutes Apgar score (7.9 vs. 7.6; p = .31), advanced newborn resuscitation (26 vs. 31.5%; p = .44), maximum FiO2 (45.5 vs. 48; p = .58), and initial inotropic requirements (10.3 vs. 20.8%; p = .55). ConclusionsThis study found no correlations between MgSO4 therapy and meconium obstruction or cardiorespiratory failure.

Influence of prenatal maternal corticosteroid therapy on clinical and metabolic features and pulmonary function of preterm newborn puppies

Although the effects of antenatal corticosteroid therapy in clinical improvement and pulmonary maturation in preterm have been described, little is known on premature newborn puppies. This study aimed to evaluate the effect of maternal administration of a single dose of prenatal betamethasone on lung function of preterm newborn puppies in the first hours of life, especially from the clinical point of view and acid-base balance. A prospective study was conducted involving 21 puppies allocated into three experimental groups: Term Group (63 days post-ovulation), Preterm-Treated Group (57 days post-ovulation and maternal administration of a single dose of 0.5 mg/kg of betamethasone) and Preterm-Control Group (57 days post-ovulation). Puppies were analyzed clinically through the Apgar score, heart rate, respiratory rate and neurological tests (muscular tone and irritability reflex) and for oximetry and blood acid-base balance in distinct experimental moments. Premature puppies had marked degree of prematurity, reversed by maternal administration of betamethasone. Prenatal corticosteroid therapy promoted better pulmonary and metabolic condition, with more efficient compensatory response to acid-base imbalance and better pulmonary gas exchange capacity. Therefore, prenatal treatment with betamethasone can be adopted as clinical lung maturation protocol for pregnancies at risk in order to prevent low vitality and increase neonatal survival.

Does corticosteroid treatment during the pre and postnatal periods affect the neurodevelopmental outcome of premature newborns?

Glucocorticoids, widely used in the perinatal period, may be associated with adverse neurodevelopmental effects. To analyze neurodevelopmental outcomes in a cohort of very low birth weight newborns treated with antenatal and/or postnatal corticosteroids. This was a prospective cohort study in which we included all very low birth weight babies admitted to the neonatal intensive care unit of a tertiary hospital between 2008 and 2013. We compared the neurodevelopment among very low birth-weight newborns who did not receive prenatal corticosteroid therapy and those who received a complete course (two doses of 12 mg betamethasone) and an incomplete course (one dose), and between those who did not receive postnatal corticosteroid therapy and those who received it (systemic dexamethasone after the first week of life). Motor, neurosensory and cognitive functions, as well as behavior disorders during the first two years of age were evaluated. A total of 225 very low birth weight newborns were analyzed; 83.6% received prenatal corticosteroid therapy (24% incomplete treatment schedule and 59.6% complete schedule). Only 13.3% received systemic dexamethasone during the postnatal period. Neurological monitoring was performed corticosteroid therapy and more neurological disorders, and no significant differences were found among those who received complete and incomplete courses of prenatal corticosteroid therapy. These results did not demonstrate an association between perinatal corticosteroid therapy and worse neurodevelopmental outcomes in very low birth weight newborns.

Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study: 2-Year Outcomes

The aim of this study was to determine the effects of repeated courses of prenatal corticosteroid therapy versus placebo on death or neurologic impairment among the children enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study, at 18 to 24 months of age. A total of 2305 infants were eligible for follow-up evaluation; 2104 infants (1069 in the prenatal corticosteroid therapy group and 1035 in the placebo group) were monitored. The primary outcome was death or neurologic impairment, defined as either cerebral palsy or cognitive delay, at 18 to 24 months of age. The secondary outcomes were measurements of growth (height, weight, and head circumference). Children exposed to multiple courses of prenatal corticosteroid therapy had similar rates of death or neurologic impairment, compared with children exposed to placebo (148 children [13.8%] vs 142 children [13.7%]; odds ratio: 1.001[95% confidence interval: 0.75-1.30]; P = .95). They had a mean weight of 11.94 kg, compared with 12.14 kg in the placebo group (P = .04), a mean height of 85.51 cm, compared with 85.46 cm (P = .87), and a mean head circumference of 48.18 cm, compared with 48.25 cm (P = .45). Multiple courses of prenatal corticosteroid therapy, given every 14 days, did not increase or decrease the risk of death or neurologic impairment at 18 to 24 months of age, compared with a single course of prenatal corticosteroid therapy. Continued follow-up monitoring of these children is necessary to assess neurobehavioral function, school performance, and possible susceptibility to disease.

Risk Factors and Estimation Tool for Death Among Extremely Premature Infants: A National Study

The goals were to assess risk factors and mortality rate changes over time and to develop simple estimates of mortality rates for specific groups of infants at 23 to 26 weeks of gestation. Data from the Israel national very low birth weight infant database on 3768 infants born in 1995-2006 with gestational ages (GAs) of 23 to 26 weeks were evaluated, and we developed a tool for estimating infants' mortality rates. Major factors associated with death were GA, gender-specific birth weight percentile, prenatal steroid therapy, and multiple births. There was a steady decrease in mortality rates for all GAs during the study period. In 2004-2006, mortality rates before discharge were 89%, 67%, 46%, and 26% for infants with GAs of 23, 24, 25, and 26 weeks, respectively. Estimated mortality rates were calculated as the sum of the percentages determined for each of 4 parameters, as follows: GA of 26, 25, 24, or 23 weeks, 0%, 17%, 34%, and 51%, respectively (P < .001); birth weight percentile of >75th, 25th to 75th, or <25th, 0%, 16%, and 32%, respectively (P < .001); no prenatal steroid treatment, +22% (P < .001); multiple birth, +7% (P = .1). Estimated mortality rates for the 48 subgroups of infants ranged from 0% to 100% and correlated well with observed rates (intraclass correlation coefficient: 0.89). Mortality rates for infants born at 23 to 26 weeks of gestation could be estimated simply on the basis of GA, gender-specific birth weight quartiles, prenatal corticosteroid therapy, and multiple births.

Prenatal Corticosteroids — Early Gain, Long-Term Questions

A single course of prenatal corticosteroid therapy has been shown to accelerate fetal lung maturation when premature delivery is imminent.13 This therapy reduces morbidity and mortality in premature newborns by reducing the incidence of respiratory disease and dependence on mechanical respiratory support. Longer-term follow-up has revealed no adverse effects on neurodevelopmental outcomes or growth, and this treatment is routinely recommended for women at risk for premature delivery between 24 weeks and 33 weeks of gestation.2,3 Prenatal corticosteroid therapy accelerates fetal lung maturation through a complex interaction of hormonal and intercellular signaling that leads to differentiation of the surfactant . . .

Prenatal Corticosteroids

After completing this article, readers should be able to: 1. Describe the standard of care for prenatal corticosteroids for women in preterm labor prior to 34 weeks’ gestation. 2. Describe the effects of prenatal corticosteroids on the fetus. 3. List the preferred corticosteroid for prenatal treatments. 4. Explain the recommendation regarding not using repetitive courses of prenatal corticosteroids. Prenatal glucocorticoids are standard of care for women at high risk of preterm delivery prior to 34 weeks’ gestation because randomized, controlled trials and extensive meta-analyses demonstrate decreased death and improved outcomes, primarily related to less respiratory distress syndrome (RDS) and a decreased incidence of intraventricular hemorrhages (IVH) (Fig. 1). (1) However, it is worth remembering that the benefits of prenatal corticosteroids initially were demonstrated in 1972, and most of the trials were completed before 1985. Most infants in the trials were delivered after 28 weeks’ gestation and in the presurfactant era, when mortality rates for infants whose birthweights were less than 1 kg were high and when obstetric management differed from current practice. Maternal corticosteroid therapy is validated practice, but care strategies proven to be effective may lose effectiveness as other aspects of care change and the target population most likely to benefit changes. This review asks a series of questions to frame the overriding question of how antenatal corticosteroids should be used in 2006. Figure 1. Meta-analysis of randomized controlled trials of prenatal corticosteroids. Adapted from Crowley. (1) The current recommendations come from the 1994 National Institutes of Health (NIH) Consensus Conference and were reinforced by a second NIH Consensus Conference in 2000. (2) The key points from the guidelines are: 1. The benefits of prenatal corticosteroids outweigh any risks that have been identified. The benefits include decreased death and decreased incidence of RDS and IVH. 2. All fetuses at 24 to 34 weeks’ gestation are candidates …

Valoración del test de Ballard en la determinación de la edad gestacional

The New Ballard Score (NBS) is commonly used to estimate gestational age (GA) in the newborn. The aims of this study were: a) to determine the reliability of the NBS; b) to estimate the agreement between two methods of GA assessment, NBS and ultrasonography (US) or last menstrual period (LMP); c) to estimate the agreement between NBS and US/LMP in distinct subgroups of neonates. We performed a prospective, blind study. NBS was performed in neonates born in Hospital 12 Octubre, Madrid before the age of 48 hours. The level of agreement was estimated with two analytical parameters: the intraclass correlation coefficient (ICC) and the mean differences method (MD). Inter-observer agreement was very good (ICC > 0.8). Agreement between US/LMP and NBS was good (ICC = 0.6-0.8). In infants with lower weight or GA, and in those whose mothers had received prenatal corticosteroid therapy, NBS tended to overestimate GA compared with US/LMP (MD = 1.2-2.9). The agreement between two observers in NBS assessment was very good. The agreement between NBS and US/LMP was good, but differences of more than 2 weeks in GA were frequent. In very preterm newborns and in infants whose mothers had received prenatal corticosteroid therapy, NBS tends to overestimate GA.

Who remains undelivered more than seven days after a single course of prenatal corticosteroids and gives birth at less than 34 weeks?

Minimal information exists as to how women who give birth more than seven days after initial corticosteroid treatment, who may benefit from repeat prenatal corticosteroids, differ from women who give birth within seven days, at < 34 weeks gestation. To examine the differences, if any, between women who received a single course of prenatal corticosteroids and remained undelivered more than seven days later and women who gave birth within seven days of treatment, at < 34 weeks gestation. Retrospective cohort. Women's and Children's Hospital, Adelaide. Women who gave birth at < 34 weeks gestation from 1 January 1994 to 31 December 1996. Data were extracted from medical records and retrieved from the hospital's database. MAIN POTENTIAL PREDICTORS COLLECTED: Prenatal corticosteroid exposure, reason for risk of preterm birth, maternal demographics and previous and current obstetric history. Of the 506 women, 122 (24%) remained undelivered more than seven days following prenatal corticosteroid therapy Initial corticosteroid treatment was given on average 1.6 weeks earlier to women who remained undelivered more than seven days after treatment. Women who were given prenatal corticosteroids for placenta praevia (RR 6.03, 95% CI 2.67-13.61, p < 0.01) or cervical incompetence (RR 3.40, 95% CI 1.06-10.95, p = 0.04) were more likely to give birth more than seven days after corticosteroid treatment. Women who give birth very preterm, who remain undelivered more than seven days after prenatal corticosteroids, differ in the reasons for and timing of their first course from women who give birth within seven days.

Lung physiological and metabolic changes in lambs with congenital diaphragmatic hernia after administration of prenatal maternal corticosteroids

Background/Purpose: Improved outcomes of preterm infants born to mothers treated prenatally with corticosteroids have been documented. The authors investigated the role of prenatal maternal corticosteroid therapy in congenital diaphragmatic hernia (CDH). Methods: Five CDH lambs of ewes given 0.5 mg/kg betamethasone intravenously 24 hours before delivery (single-dose), four CDH lambs of ewes similarly dosed at 48 and 24 hours before delivery (double-dose), five untreated CDH lambs and five control lambs were studied. After 2 hours of ventilation, compliance, arterial oxygen (p o 2) and carbon dioxide (p co 2) concentrations were recorded. Lavage protein and phospho-lipid levels were measured, and lung tissue was analyzed for antioxidant enzyme activity (AOE). Results: No improvement in gas exchange was noted in either treatment group. Significant increases in compliance ( P = .02) were noted in the double-dose steroid group, which were different from that of untreated CDH lambs or controls. Minimal changes in AOE activities were seen with steroid administration. Conclusions: Although the metabolic changes were not significant, the marked improvement in compliance seen in the double-dosed steroid group suggests a potential role for prenatal maternal corticosteroids in CDH. Further timing and dosage studies are warranted in this model.

OFFICE CARE OF THE SMALL, PREMATURE INFANT

About 1% of infants are born before 32 weeks of pregnancy, and 0.9% have a birthweight of 1500 gm or less. More of these premature infants are surviving. Contributing factors include prenatal corticosteroid therapy and early surfactant therapy to reduce the incidence of respiratory distress syndrome. Because of this, more family physicians are providing office care for premature infants after discharge from neonatal intensive care centers. These infants require special care in the office as well as the neonatal intensive care unit. The goal of the family physician's care should be to minimize mortality and morbidity. This article summarizes recommendations for office care of the surviving premature infant.

ANTENATAL TREATMENT WITH THYROTROPIN RELEASING HORMONE (TRH) FOR PREVENTION OF NEWBORN LUNG DISEASE

Although prenatal corticosteroid therapy is efficacious and safe it does not always prevent RDS, and infants of low birth weight often develop chronic lung disease. To study effects of thyroid hormone, we performed a blinded, randomized trial in which 404 women with threatened preterm delivery at <32 wk gestation received betamethasone plus TRH (4 doses of 400 μg at 8-h intervals) or betamethasone plus placebo. 103 fully treated infants of <1500 g birth weight were evaluated for outcome. TRH therapy did not affect total RDS (47.3% vs 58.3% in control) or occurrence of severe disease (12.7% vs 25% in control, p=0.11). Significantly fewer TRH-treated infants developed chronic lung disease (requirement for supplemental O2 at 28 days of age), 17.6% vs 43.9% in control (p<0.01). TRH increased maternal plasma TSH by 100% at 2-4 h after treatment and decreased levels by 28-34% at 5-36 h. In cord blood of treated infants delivered at 2-6 h, TSH, T3 and PRL were all increased about 2-fold vs control and free T4 was increased 19%. In infants delivering at 7-36 h, cord TSH and T3 were decreased 62 and 54%, respectively, and all thyroid hormones were lower at 2 h of age. Conclusion: Prenatal TRH therapy produces a sustained elevation of fetal thyroid hormones and reduces the occurrence of chronic lung disease in premature infants. Pituitary-thyroid function is transiently suppressed after treatment, to a greater extent in fetus than mother.

Prenatal and postnatal corticosteroid therapy to prevent neonatal necrotizing enterocolitis: a controlled trial

To determine whether prenatal corticosteroid therapy would reduce the incidence of neonatal necrotizing enterocolitis (NEC), we assigned a total of 466 women admitted in premature labor either to receive placebo (group A, n = 256), if delivery was expected to occur within 24 hours of admission, or to receive betamethasone (group B, n = 210) if delivery was expected to take place more than 24 hours after admission. All women were free of severe medical complications or drug therapy; cases of intrauterine growth retardation or premature rupture of the membranes were excluded. Their newborn infants, excluding malformed, congenitally infected, and growth-retarded infants, were enrolled in the study unless they had died before the age of 10 postnatal days. Babies born to group A mothers (n = 248) were further assigned to a treatment group (group A1, n = 130) receiving dexamethasone, 2 mg/kg/day by intravenous injection during the first 7 days of life, or to a control group (group A2, n = 118) receiving 10% dextrose solution placebo. Group B infants (prenatal betamethasone, n = 205) received neither treatment nor placebo. The incidence of NEC in group A1 was 6.9% (9/130), and in group A2 it was 14.4% (17/118) (p less than 0.05). In group B the incidence was 3.4% (7/205); this was much lower than in group A2 (p less than 0.01) and lower than in group A combined (10.4%) (p less than 0.01). There was no death from NEC and no surgical intervention among group B patients. The mortality rate for group A1 (11%) was lower than for group A2 (56%) (p less than 0.02). There were fewer indications for surgical intervention for NEC in group A1 than in group A2. Histologic studies confirmed bowel ischemia in all specimens analyzed. These data support the hypothesis that the incidence of NEC is significantly reduced after prenatal steroid treatment. Although postnatal therapy with steroids does not decrease the incidence as effectively as prenatal therapy, it improves clinical outcome of NEC.

The Effect of Prenatal Dexamethasone Treatment on Oxygen Toxicity in the Newborn Rat

To determine whether prenatal corticosteroid therapy had adverse effects on the tolerance of the newborn lung to prolonged high O2 exposure, pregnant rats were given injections of dexamethasone (0.2 mg/kg) at 48 and 24 hours prior to parturition, and the newborn pups were placed in 96% to 98% O2 for the first seven days of life. Dexamethasone treatment resulted in significant decreases in body weight (-17%), lung weight (-30%), lung weight/body weight (-22%), and lung DNA (-18%) compared to untreated rat pups. Despite this growth inhibition, the dexamethasone-treated pups had improved survival in hyperoxia (36/48 = 75% vs 29/48 = 60% for untreated rats, P = .055). In addition, substantial "catch-up" lung growth had occurred by seven days and was complete in 28-day-old rats. Dexamethasone did not interfere with normal pulmonary antioxidant enzyme responses to hyperoxia. Thus, prenatal dexamethasone did not compromise the relative tolerance of the newborn to pulmonary O2 toxicity.

SURVIVAL TIME OF CIRCULATING LONG-ACTING THYROID STIMULATOR IN NEONATAL THYROTOXICOSIS: IMPLICATIONS FOR DIAGNOSIS AND THERAPY OF THE DISORDER

We have described an infant with neonatal thyrotoxicosis who developed supraventricular tachycandia, goiter, and periorbital edema. Both the baby's and mother's sera contained the long-acting thyroid stimulator (LATS). While the level of LATS remained unchanged in the serum of the mother, it rapidly fell in the serum of the infant. The biological half-life of LATS in the infant's serum was calculated to be 6 days, and by the age of 21 days no LATS activity could be detected. Based on these findings, antithyroidal treatment which had been instituted soon after birth was discontinued on the thirty-eighth day without recurrence of signs or symptoms of thyrotoxicosis. In addition to conventional antithyroid therapy for thyrotoxicosis, exchange transfusion and prenatal corticosteroid therapy of the mother may be considered when neonatal or maternal serum LATS titers, respectively, are very high.