Antenatal Rescue Course of Glucocorticoids in Threatened Premature Birth
Antenatal Rescue Course of Glucocorticoids in Threatened Premature Birth
Administration of steroid to the mother in imminent preterm delivery is a known effective
 practice to decrease the risk of respiratory distress syndrome and intraventricular
 haemorrhage in preterm infants if given with a week of the preterm delivery. This randomized
 clinical trial is performed to test the possibility whether the repeat dose of steroid
 results in further reduction of these diseases in case the mother is in imminent preterm
 delivery more than a week after the first antenatal steroid treatment.
RANDOMIZED TRIAL ON EFFICACY AND SAFETY OF THE ANTENATAL RESCUE COURSE OF GLUCOCORTCOID IN
 THREATENED PREMATURE BIRTH (ACG trial)

 Introduction

 Prematurity is the main cause of neonatal mortality and morbidity. Immature infants have many
 serious diseases such as respiratory distress syndrome (RDS), intracranial hemorrhage (ICH),
 chronic lung disease (CLD), necrotizing enterocolitis (NEC) and retinopathy of prematurity
 (ROP). Corticosteroids have the maturational effects on fetal cardiovascular, respiratory,
 nervous and gastrointestinal systems (1). Antenatal corticosteroids (ANC) have been widely
 used for prevention of RDS and other serious diseases in preterm infants since 1972's, when
 the controlled trial of antepartum glucocorticoid treatment was published. Administration of
 s of 12 mg of betamethasone given twice intramuscularly 24 hours apart has shown to be
 effective (2,3,4,39). Strong evidence exists for neonatal benefits from a complete course of
 ANC starting at 24 hours and lasting up to 7 days after treatment (2,39). Betamethasone and
 dexamethasone have similar biological activity and both are associated with a significant
 reduction in the risk of RDS, but only betamethasone with a significant decrease of the
 neonatal mortality. The clinical benefit had not been documented beyond 7 days after the
 onset of ANC therapy. (1,2)

 Several randomized studies have shown that a single course of antenatal corticosteroid
 treatment improves the survival of preterm infants born at 24-34 weeks gestation and
 decreases the incidence of RDS, ICH and NEC. ANC therapy reduces the incidence of RDS by
 approximately 50%.(1,2) ANC treatment also reduces the need of exogenous surfactant (4). The
 protective effect against RDS is thought to be due to the structural maturation of the lungs,
 increased surfactant synthesis, improved resistance to lung injury and improved
 cardiovascular adaptation. Glucocorticoid speeds up the normal thinning of the gas-exchange
 walls with double capillary loops between the air sacs. ANC thus accelerates the structural
 development of the respiratory airways, but reduces the number of alveoli. Glucocorticoid
 increases surfactant synthesis by enhancing maturation of the surfactant- producing type II
 pneumocytes and stimulating the secretion of surfactant complex (1,6,7,8,9,40). Serial doses
 of ANC may possibly downregulate steroid receptors resulting in decreased or disordered
 surfactant production.(ref) ANC has not been shown to decrease the incidence of CLD at 28
 days of age either in the meta-analysis or in the recent retrospective studies (2,13,14,15).

 ANC treatment is associated with maturation of the cardiovascular system and normalisation of
 the low blood pressure in the small premature infant at birth.(ref) This influence was
 evident after administration of surfactant.(4) According to meta-analysis, ANC had no effect
 on the incidence of PDA. However in several studies, use of ANC was associated with increased
 spontaneous closure of PDA(2,3,4, ).

 ANC decreases the incidence of ICH in preterm infants (2,3,4). Severe prematurity decreases
 autoregulation of the cerebral circulation and predisposes to ICH or cerebral ischemia.
 Glucocorticoids accelerate differentiation of neuronal cells and possibly enhance maturation
 of germinal matrix vessels (1,33,34). ANC therapy has been associated also with a lower
 incidence of periventricular leukomalacia (PVL) and cerebral palsy (CP), but these effects
 were not significant in Crowley's meta-analysis (2,3,4,5). In a recently published
 retrospective study, antenatal administration of betamethasone was associated with a
 decreased risk of PVL compared to antenatal dexamethasone or no treatment (17).

 Betamethasone is clinically used as a mixture of betamethasone phosphate (6 mg) and
 betamethasone acetate (6 mg), providing a rapid exposure from the phosphate form and a
 sustained exposure from the acetate form. Maximal fetal serum level of betamethasone was
 attained 1-2 hours after ANC treatment (27). The half life of antenatally administered
 betamethasone is about 12 hours in fetal circulation (1,36). Decrease in the incidence of RDS
 is evident when ANC is administered between 24 hours and 7 days before delivery. However, the
 incidence of ICH is decreased even with treatment initiated less than 24 hours prior to
 delivery (2,3,4). According to the animal studies the short term ANC (<24 hours) improves the
 postnatal lung function, decreases the protein leak into the lung and alters postnatal blood
 pressure regulation in the premature. ANC also seems to augment the postnatal neuroendocrine
 and endocrine responses to hypoxic challenge (28,29,30).

 According to meta-analysis there is no significant decrease in birthweight and in physical or
 psychological development at the age 3-12 years following a single course of ANC treatment of
 fetuses (2,18,19). According to follow-up studies, prenatal single course of steroid
 treatment is safe and enhanced survival is not associated with a higher incidence of
 disabilities or developmental disturbances in survivors during childhood and young adulthood
 (2,3,5,18,19,35). Single course of ANC treatment did not increase the risk of fetal or
 neonatal infections or the incidence of maternal infections (2). When administered during the
 subclinical chorioamnionitis, ANC treatment seem to decrease the incidence of RDS, ICH, PVL
 and neonatal mortality without apparent increase in neonatal sepsis (32).

 However, there is concern about possible negative effect of multiple course of ANC on
 birthweight, head circumference and growth later in childhood. Data from numerous animal
 studies suggest that ANC has a negative effect on pre- and postnatal growth. Most studies
 deal with rodents who have a short gestation and period of growth (10,11,12,37). In animal
 studies multidose ANC exposure has also decreased lung growth, which seems to be irreversible
 and persistent into adulthood (10,11,12). Also, in several animal studies ANC exposure has
 shown decreased brain growth and cell proliferation, which may also be due to short duration
 of gestation and long duration of exposure (10,11,12,37).

 There are concerns about potential suppressive effects of ANC on the fetal
 hypothalamus-pituitary-adrenal axis. Transient suppression of the pituitary-adrenal glands in
 preterm infants whose mothers have received 1-2 doses of antenatal glucocorticoid, reportedly
 recovers within 7 days of life (23,24,25,26,36). Infants delivered shortly after one course
 of ANC are normally responsive to stress after birth (e.g. RDS and asphyxia).(36)

 Clinical practice administering antenatal corticosteroids varies greatly between individual
 centers during the late 1990's. The practice of repeating the course of ANC has become
 widespread. However the safety or efficacy of serial courses of glucocorticoid is not known.
 According to recently published non-randomized studies there is conflicting data on growth
 and neonatal morbidity of infants exposed to single vs. multiple course of ANC (13,14,15).
 There is also concern particularly in women with prolonged premature rupture of fetal
 membranes (PPROM) that repetitive doses may increase maternal and fetal infections (21,22).
 In a retrospective study the multiple course of ANC was associated with an increased
 incidence of maternal postpartum infections (13).

 The effect of multiple courses of ANC on the HPA-axis is not well known. In recent studies a
 mild adrenal suppression was evident in some of the preterm infants whose mothers received
 more than eight courses of ANC (15). It has also been proposed that perinatal stress and
 exposure to corticosteroids induces long lasting changes in HPA-axis and is associated with a
 decrease in stress induced CRH release in adulthood (24,34). However, there is no existing
 data about function of HPA-axis in young adults, who have been exposed to antenatal
 corticosteroids during fetal life.

 There is insufficient data about optimal interval of ANC administration. According to recent
 studies there is not additive positive effects of the practice of repeating the course of ANC
 at 7 days intervals. However, it is known that the positive influence of the one course of
 ANC is not evident after 7 days of administration. It is interesting whether one additional
 rescue course of ANC given within 24 hours before premature delivery is more effective than
 single course of ANC. No prospective studies or randomized, controlled trials comparing
 single versus second rescue course of antenatal corticosteroids have been published.

 Specific aim and hypothesis

 The present aim is to study whether in recipients of ANC a single dose of betamethasone given
 shortly before spontaneous or elective premature birth (gestation 24 + 0 - 33 + 6 wk)
 improves the neonatal outcome without causing serious side effects. According to protocol,
 aim is to start the placebo or the second rescue course of ANC in 48 hours before expected
 delivery. The first hypothesis states that administration of second rescue course of ANC is
 more effective than the single course of ANC in increasing the intact survival at term of all
 infants without major neonatal morbidity, defined by the protocol. The principal outcome is
 survival of premature infants without major morbidity until the age of 36+0 weeks and
 survival of infants born at term during early neonatal period without the major morbidity, as
 defined by the protocol.

 Study design

 Present study is a multicenter, randomized, blinded, placebo-controlled trial comparing the
 benefits and side effects of single vs. second rescue course of antenatal corticosteroid.

 Entry criteria

 The pregnant women will be eligible for the trial entry if all following criteria are met:

 -  administration of a course of antenatal corticosteroid at least 7 days before the trial
 entry

 -  gestational age is less than 33.0 weeks 6 days*

 -  very high risk of premature delivery**

 -  none of the following therapies complications or therapies maternal long term systemic
 corticosteroid therapy severe clinical chorioamnionitis (maternal fever, increased CRP
 or another acute phase protein, uterine tenderness) lethal disease of the fetus

 -  informed consent obtained

 -  premature rupture of membranes is not contraindication for the trial entry

 *Gestational age will be calculated from the mother's last menstrual period and
 confirmed by ultrasound before 20 weeks' gestation. In case the discrepancy in the
 estimates exceeds two weeks, ultrasound date is accepted.

 **Very high risk of premature delivery is described as follows:

 -  elective delivery within within 4-48 hours, as indicated by the obstetrician on the
 basis of the clinical status of the mother and/or the fetus

 -  very high risk of spontaneous delivery within 4-48 hours, i.e.

 -  cervix is open > 3 cm

 -  contractions of the uterus at 5-10 min intervals

 -  rupture of the membranes after the first course of ANC

 -  fetal and/or maternal indication for elective premature delivery or cesarean section

 Trial entry

 The investigator or his/her designated representative will evaluate the pregnant women for
 the above eligibility criteria. Administration of one course of antenatal glucocorticoid
 identifies the pregnant mothers that are potentially eligible to present study. Oral and
 written informed consent will be obtained from the women (if appropriate). The study entry
 (randomization and administration of the drug) takes place when all entry criteria are met.
 The parturient and her randomization number will be recorded on the trial data form and on
 patient records to enable later description of the women and to assist follow up. At the time
 of delivery the infants of the trial participants will be recorded to the trial data form and
 on patient records.

 Randomization

 The eligible women will be randomly and blindly assigned to receive either betamethasone or
 saline placebo. The randomization will take place separately in each Center according to the
 following strata:

 I gestation at entry less than 28.0 weeks + 0 days and singleton pregnancy

 II gestation at entry 28.0 weeks + 0 days or more but less than 33.0 weeks + 6 days and
 singleton pregnancy

 III gestation at entry less than 28.0 weeks + 0 days and multiple pregnancy

 IV gestation at entry 28.0 weeks + 0 days or more but less than 33.0 weeks + 6 days and
 multiple pregnancy

 Study intervention

 The first course of ANC prior to the trial entry will be given according to the clinical
 indications of the Center. Administration of further courses of ANC before the trial entry
 will disqualify the mother from the ACG trial. The study course of betamethasone or placebo
 will be given to each eligible woman at least 7 days after the first course of ANC. After the
 entry criteria are met betamethasone (12mg) or placebo (normal saline) will be drawn to a
 sealed syringe containing the randomization number. The drug or placebo is administered
 intramuscularly.

 Within 1 hour the betamethasone dose increases the fetal serum levels of glucocorticoid to
 those obtained during neonatal stress

 Other obstetric and neonatal management

 Other management given to the participating women will be decided by the obstetrician. After
 the entry to the trial administration of ANC outside study protocol is not allowed. In an
 event premature delivery did not occur after ACG, any further administration of ANC is not
 indicated. The premature infants are treated in whatever way their condition demands, the
 decision is made by pediatrician. The ACG trial infants born after 33.0 + 6 weeks of
 pregnancy are included in the neonatal and the follow-up studies.

 Fetuses that died after the trial entry will be recorded. The pathologic examination of these
 fetuses is strongly encouraged.

 Measurement of outcome

 Primary outcome of the trial:

 Term birth or survival of the infants at the gestational age of 36.0 weeks + 0 days without
 any of the following:

 RDS need of supplemental oxygen > 48 h or surfactant therapy and characteristic radiographic
 findings

 Severe ICH (grades 3-4) infants born in term will be evaluated by ultrasound

 Maternal-antenatal outcomes:

 Clinical chorioamnionitis Any maternal infection Fetal death

 Secondary outcomes after birth:

 CLD requirement of supplemental oxygen at 36 weeks' postmenstrual age PVL (gr 3-4) Severe NEC
 (Bell stages 3-4) perforation of the intestine intestinal pneumatosis air in portal vein ROP
 according to The International Classification of Retinopathy of Prematurity

 Neonatal infections early neonatal infections (onset < 72 hours) proven nosocomial bacterial
 or fungal sepsis during neonatal period (days 3-28) Gastrointestinal bleeding or perforation
 Number of days on assisted ventilation Number of days on supplemental oxygen Duration of
 primary hospital stay Growth characteristics at birth

 Treatments requirements:

 surfactant postnatal steroids indomethacin for PDA PDA surgery

 Primary outcome at follow up study

 Survival without neurologic, sensory or neuromotor impairment at the age 2 years, corrected
 for gestation. All infants will be studied. For the high-risk group, the following indices
 and studies will be performed:

 Mental Development Index (MDI) (<70) Psychomotor development will be measured by Bayley Scale
 (PDI) Behavioral development index (percentile) Definition of abnormalities in neurological
 status, speech development, major visual handicap and hearing defect

 Secondary outcomes during the follow-up:

 Growth characteristics during the first two years of corrected age Recurrent infections
 Reactive airway disease Hospital treatment during early childhood

 Data collection

 Information will be collected at the time of delivery, during the hospital stay and when the
 baby leaves the hospital or dies. Perinatal data will include prenatal history, assessment of
 entry criteria and following information of postnatal condition: blood pressure monitoring,
 assessment of growth at birth, day 28 and at 36 weeks gestational age (height, weight and
 head circumference). Cranial ultrasound will be made on all infants at least between days 4-8
 of life and at 36.0 w + 0 d (± 3 days) gestational age or before discharge. The worst grade
 of ICH and PVL will be reported. The first ophthalmologic examination for retinopathy of
 prematurity will be done 4 to 7 weeks after birth or at 32 weeks gestational age.

 Clinical status will be assessed at the time of discharge. The cause of death will be defined
 when possible at autopsy.

 The surviving children will be studied at two years of age (corrected for gestational age).
 Their growth and neurodevelopment will be evaluated using a questionnaire and a clinical
 evaluation.

 Sample size justification

 The primary goal of the study is to detect the effects of two vs. single course of ANC on
 survival without RDS and/or severe ICH (grade 3-4) by 36 weeks + 0 days of gestational age.

 Sample size analysis is based on morbidity and mortality from the Finnish perinatal
 statistics (National Research and Development Centre for Welfare and Health) and from Vermont
 Oxford Network Database (VON). We estimate that a second additional dose of betamethasone
 would increase the survival without RDS and severe ICH from 50% to 62.5%. According to power
 analysis the sample size of 220 women would be required in each arm to reject the null
 hypothesis with and α of 0.05 and power of 80%.

 The aim of the follow up study is to find out that one course of ANC result in equal or
 better neurodevelopmental outcome at the corrected age of two years, compared a single course
 of ANC.

 Statistical analysis

 Primary outcome

 Analysis of the primary outcomes will be based on an intention to treat analysis of all
 randomized subjects. Another analysis will be performed excluding infants who had congenital
 lethal malformation that was not detected at the onset. The outcome will be compared for the
 two vs. single course of ANC using the Mantel-Haenszel chi square test stratifying by the
 prenatal variables.

 Secondary outcomes

 The frequencies of categorical outcomes will be compared using appropriate chi square tests.
 The growth parameters, duration of ventilation, supplemental oxygen administration and
 hospitalization will be compared using analysis of variance or nonparametric tests when
 applicable. Survival rate will be compared using chi square tests and survival to term using
 survival analysis.

 Interim analysis

 The neonatal and the follow-up results for adverse outcomes will be prepared by the Data
 Safety Monitoring Committee when altogether 350 study infants have reached to the term or
 when the trial has been going on for 24 months, whichever comes first.

 Ethical considerations

 A written informed consent will be obtained from all the parents of the infants before the
 enrollment. The participation in the study does not cause any extra cost to the mother or the
 family. Participation is voluntary and withdrawing from the study is possible whenever
 desired during the pregnancy, the hospital stay or during the follow up period. Withdrawal
 does not affect the treatment or the follow up of the infant or the mother. If desired,
 approval from the ethical committees of each participating center will be obtained.

 Publication policy

 The perinatal-neonatal trial and the follow up study will be published separately. The list
 of authors includes Antenatal Multiple Betamethasone Trial Study Group (AMBTS). Each
 participant of the study from each Center will be listed. Each Center has an antenatal and a
 postnatal trial coordinator.

 Ancillary studies

 The participants are free to perform ancillary studies provided that a separate protocol,
 submitted together with the present one, is accepted by the local ethics committees.
Inclusion Criteria:

 The pregnant women will be eligible for the trial entry if all following criteria are met:

 -  administration of a course of antenatal corticosteroid at least 7 days before the
 trial entry

 -  gestational age is less than 33.0 weeks 6 days*

 -  very high risk of premature delivery**

 -  none of the following therapies complications or therapies maternal long term systemic
 corticosteroid therapy severe clinical chorioamnionitis (maternal fever, increased CRP
 or another acute phase protein, uterine tenderness) lethal disease of the fetus

 -  informed consent obtained

 -  premature rupture of membranes is not contraindication for the trial entry

 *Gestational age will be calculated from the mother's last menstrual period and
 confirmed by ultrasound before 20 weeks' gestation. In case the discrepancy in the
 estimates exceeds two weeks, ultrasound date is accepted.

 **Very high risk of premature delivery is described as follows:

 -  elective delivery within within 4-48 hours, as indicated by the obstetrician on the
 basis of the clinical status of the mother and/or the fetus

 -  very high risk of spontaneous delivery within 4-48 hours, i.e.

 -  cervix is open > 3 cm

 -  contractions of the uterus at 5-10 min intervals

 -  rupture of the membranes after the first course of ANC

 -  fetal and/or maternal indication for elective premature delivery or cesarean section