The effect of betamethasone versus dexamethasone on fetal biophysical parameters

Dexamethasone and Dexamethasone Phosphate: Effect on DMPC Membrane Models

Dexamethasone (Dex) and Dexamethasone phosphate (Dex-P) are synthetic glucocorticoids with high anti-inflammatory and immunosuppressive actions that gained visibility because they reduce the mortality in critical patients with COVID-19 connected to assisted breathing. They have been widely used for the treatment of several diseases and in patients under chronic treatments, thus, it is important to understand their interaction with membranes, the first barrier when these drugs get into the body. Here, the effect of Dex and Dex-P on dimyiristoylphophatidylcholine (DMPC) membranes were studied using Langmuir films and vesicles. Our results indicate that the presence of Dex in DMPC monolayers makes them more compressible and less reflective, induces the appearance of aggregates, and suppresses the Liquid Expanded/Liquid Condensed (LE/LC) phase transition. The phosphorylated drug, Dex-P, also induces the formation of aggregates in DMPC/Dex-P films, but without disturbing the LE/LC phase transition and reflectivity. Insertion experiments demonstrate that Dex induces larger changes in surface pressure than Dex-P, due to its higher hydrophobic character. Both drugs can penetrate membranes at high lipid packings. Vesicle shape fluctuation analysis shows that Dex-P adsorption on GUVs of DMPC decreases membrane deformability. In conclusion, both drugs can penetrate and alter the mechanical properties of DMPC membranes.

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

BACKGROUND

Despite the widespread use of antenatal corticosteroids to prevent respiratory distress syndrome (RDS) in preterm infants, there is currently no consensus as to the type of corticosteroid to use, dose, frequency, timing of use or the route of administration.  OBJECTIVES: To assess the effects on fetal and neonatal morbidity and mortality, on maternal morbidity and mortality, and on the child and adult in later life, of administering different types of corticosteroids (dexamethasone or betamethasone), or different corticosteroid dose regimens, including timing, frequency and mode of administration.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (9 May 2022) and reference lists of retrieved studies.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 11 trials (2494 women and 2762 infants) in this update, all of which recruited women who were at increased risk of preterm birth or had a medical indication for preterm birth. All trials were conducted in high-income countries. Dexamethasone versus betamethasone Nine trials (2096 women and 2319 infants) compared dexamethasone versus betamethasone. All trials administered both drugs intramuscularly, and the total dose in the course was consistent (22.8 mg or 24 mg), but the regimen varied. We assessed one new study to have no serious risk of bias concerns for most outcomes, but other studies were at moderate (six trials) or high (two trials) risk of bias due to selection, detection and attrition bias. Our GRADE assessments ranged between high- and low-certainty, with downgrades due to risk of bias and imprecision.  Maternal outcomes The only maternal primary outcome reported was chorioamnionitis (death and puerperal sepsis were not reported). Although the rate of chorioamnionitis was lower with dexamethasone, we did not find conclusive evidence of a difference between the two drugs (risk ratio (RR) 0.71, 95% confidence interval (CI) 0.48 to 1.06; 1 trial, 1346 women; moderate-certainty evidence). The proportion of women experiencing maternal adverse effects of therapy was lower with dexamethasone; however, there was not conclusive evidence of a difference between interventions (RR 0.63, 95% CI 0.35 to 1.13; 2 trials, 1705 women; moderate-certainty evidence). Infant outcomes We are unsure whether the choice of drug makes a difference to the risk of any known death after randomisation, because the 95% CI was compatible with both appreciable benefit and harm with dexamethasone (RR 1.03, 95% CI 0.66 to 1.63; 5 trials, 2105 infants; moderate-certainty evidence). The choice of drug may make little or no difference to the risk of RDS (RR 1.06, 95% CI 0.91 to 1.22; 5 trials, 2105 infants; high-certainty evidence). While there may be little or no difference in the risk of intraventricular haemorrhage (IVH), there was substantial unexplained statistical heterogeneity in this result (average (a) RR 0.71, 95% CI 0.28 to 1.81; 4 trials, 1902 infants; I² = 62%; low-certainty evidence). We found no evidence of a difference between the two drugs for chronic lung disease (RR 0.92, 95% CI 0.64 to 1.34; 1 trial, 1509 infants; moderate-certainty evidence), and we are unsure of the effects on necrotising enterocolitis, because there were few events in the studies reporting this outcome (RR 5.08, 95% CI 0.25 to 105.15; 2 studies, 441 infants; low-certainty evidence). Longer-term child outcomes Only one trial consistently followed up children longer term, reporting  at two years' adjusted age. There is probably little or no difference between dexamethasone and betamethasone in the risk of neurodevelopmental disability at follow-up (RR 1.02, 95% CI 0.85 to 1.22; 2 trials, 1151 infants; moderate-certainty evidence). It is unclear whether the choice of drug makes a difference to the risk of visual impairment (RR 0.33, 95% CI 0.01 to 8.15; 1 trial, 1227 children; low-certainty evidence). There may be little or no difference between the drugs for hearing impairment (RR 1.16, 95% CI 0.63 to 2.16; 1 trial, 1227 children; moderate-certainty evidence), motor developmental delay (RR 0.89, 95% CI 0.66 to 1.20; 1 trial, 1166 children; moderate-certainty evidence) or intellectual impairment (RR 0.97, 95% CI 0.79 to 1.20; 1 trial, 1161 children; moderate-certainty evidence). However, the effect estimate for cerebral palsy is compatible with both an important increase in risk with dexamethasone, and no difference between interventions (RR 2.50, 95% CI 0.97 to 6.39; 1 trial, 1223 children; low-certainty evidence). No trials followed the children beyond early childhood. Comparisons of different preparations and regimens of corticosteroids We found three studies that included a comparison of a different regimen or preparation of either dexamethasone or betamethasone (oral dexamethasone 32 mg versus intramuscular dexamethasone 24 mg; betamethasone acetate plus phosphate versus betamethasone phosphate; 12-hourly betamethasone versus 24-hourly betamethasone). The certainty of the evidence for the main outcomes from all three studies was very low, due to  small sample size and  risk of bias. Therefore, we were limited in our ability to draw conclusions from any of these studies.

AUTHORS' CONCLUSIONS

Overall, it remains unclear whether there are important differences between dexamethasone and betamethasone, or between one regimen and another.  Most trials compared dexamethasone versus betamethasone. While for most infant and early childhood outcomes there may be no difference between these drugs, for several important outcomes for the mother, infant and child the evidence was inconclusive and did not rule out significant benefits or harms. The evidence on different antenatal corticosteroid regimens was sparse, and does not support the use of one particular corticosteroid regimen over another.

Hyaluronic Acid-Dexamethasone Nanoparticles for Local Adjunct Therapy of Lung Inflammation

The delivery of a dexamethasone formulation directly into the lung appears as an appropriate strategy to strengthen the systemic administration, reducing the dosage in the treatment of lung severe inflammations. For this purpose, a hyaluronic acid-dexamethasone formulation was developed, affording an inhalable reconstituted nanosuspension suitable to be aerosolized. The physico-chemical and biopharmaceutical properties of the formulation were tested: size, stability, loading of the spray-dried dry powder, reconstitution capability upon redispersion in aqueous media. Detailed structural insights on nanoparticles after reconstitution were obtained by light and X-ray scattering techniques. (1) The size of the nanoparticles, around 200 nm, is in the proper range for a possible engulfment by macrophages. (2) Their structure is of the core-shell type, hosting dexamethasone nanocrystals inside and carrying hyaluronic acid chains on the surface. This specific structure allows for nanosuspension stability and provides nanoparticles with muco-inert properties. (3) The nanosuspension can be efficiently aerosolized, allowing for a high drug fraction potentially reaching the deep lung. Thus, this formulation represents a promising tool for the lung administration via nebulization directly in the pipe of ventilators, to be used as such or as adjunct therapy for severe lung inflammation.

Dexamethasone versus betamethasone for preterm birth: a systematic review and network meta-analysis

OBJECTIVE

This study aimed to evaluate the comparative clinical effectiveness and safety of dexamethasone vs betamethasone for preterm birth.

DATA SOURCES

The sources searched were MEDLINE, EMBASE, Cochrane Library, LILACS, ClinicalTrials.gov, and International Clinical Trials Registry Platform without language restrictions until October 2019 in addition to the reference lists of included studies. Field experts were also contacted.

STUDY ELIGIBILITY CRITERIA

Randomized or quasi-randomized controlled trials comparing any corticosteroids against each other or against placebo at any dose for preterm birth were included in the study.

METHODS

Three researchers independently selected and extracted data and assessed the risk of bias of the included studies by using Early Review Organizing Software and Covidence software. Random-effects pairwise meta-analysis and Bayesian network meta-analysis were performed. The primary outcomes were chorioamnionitis, endometritis or puerperal sepsis, neonatal death, respiratory distress syndrome, and neurodevelopmental disability.

RESULTS

A total of 45 trials (11,227 women and 11,878 infants) were included in the study. No clinical or statistical difference was found between dexamethasone and betamethasone in neonatal death (odds ratio, 1.05; 95% confidence interval, 0.62-1.84; moderate-certainty evidence), neurodevelopmental disability (odds ratio, 1.03; 95% confidence interval, 0.80-1.33; moderate-certainty evidence), intraventricular hemorrhage (odds ratio, 1.04; 95% confidence interval, 0.56-1.78); low-certainty evidence), or birthweight (+5.29 g; 95% confidence interval, -49.79 to 58.97; high-certainty evidence). There was no statistically significant difference, but a potentially clinically important effect was found between dexamethasone and betamethasone in chorioamnionitis (odds ratio, 0.70; 95% confidence interval, 0.45-1.06; moderate-certainty evidence), fetal death (odds ratio, 0.81; 95% confidence interval, 0.24-2.41; low-certainty evidence), puerperal sepsis (odds ratio, 2.04; 95% confidence interval, 0.72-6.06; low-certainty evidence), and respiratory distress syndrome (odds ratio, 1.34; 95% confidence interval, 0.96-2.11; moderate-certainty evidence). Meta-regression, subgroup, and sensitivity analyses did not reveal important changes regarding the main analysis.

CONCLUSION

Corticosteroids have proven effective for most neonatal and child-relevant outcomes compared with placebo or no treatment for women at risk of preterm birth. No important difference was found on neonatal death, neurodevelopmental disability, intraventricular hemorrhage, and birthweight between corticosteroids, and there was no statistically significant difference, but a potentially important difference was found in chorioamnionitis, fetal death, endometritis or puerperal sepsis, and respiratory distress syndrome. Further research is warranted to improve the certainty of evidence and inform health policies.

Glycemic control following two regimens of antenatal corticosteroids in mild gestational diabetes: a randomized controlled trial

PURPOSE

To compare 3 consecutive days of hyperglycemic response following antenatal dexamethasone regimens of 12-mg or 6-mg doses 12 hourly in diet-controlled gestational diabetes.

METHODS

A randomized controlled trial was carried out in a university hospital in Malaysia. Women with lifestyle-controlled gestational diabetes scheduled to receive clinically indicated antenatal corticosteroids (dexamethasone) were randomized to 12-mg 12 hourly for one day (2 × 12-mg) or 6-mg 12-hourly for two days (4 × 6-mg). 6-point (pre and 2-h postprandial) daily self-monitoring of capillary blood sugar profile for up to 3 consecutive days was started after the first dexamethasone injection. Hyperglycemia is defined as blood glucose pre-meal ≥ 5.3 or 2 h postprandial ≥ 6.7 mmol/L. The primary outcome was a number of hyperglycemic episodes in Day-1 (first 6 BSP points). A sample size of 30 per group (N = 60) was planned.

RESULTS

Median [interquartile range] hyperglycemic episodes 4 [2.5-5] vs. 4 [3-5] p = 0.3 in the first day, 3 [2-4] vs. 1 [0-3] p = 0.01 on the second day, 0 [0-1] vs. 0 [0-1] p = 0.6 on the third day and over the entire 3 trial days 7 [6-9] vs. 6 [4-8] p = 0.17 for 6-mg vs. 12-mg arms, respectively. 2/30 (7%) in each arm received an anti-glycemic agent during the 3-day trial period (capillary glucose exceeded 11 mmol/L). Mean birth weight (2.89 vs. 2.49 kg p < 0.01) and gestational age at delivery (37.7 vs. 36.6 weeks p = 0.03) were higher and median delivery blood loss (300 vs. 400 ml p = 0.02) was lower in the 12-mg arm; all other secondary outcomes were not significantly different.

CONCLUSION

In gestational diabetes, 2 × 12-mg could be preferred over 4 × 6-mg dexamethasone as hyperglycemic episodes were fewer on Day-2, fewer injections were needed and the regimen was completed sooner.

CLINICAL TRIAL REGISTRATION

http://www.isrctn.com/ISRCTN16613220 .

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Antenatal corticosteroid therapy: short-term effects on fetal behaviour and haemodynamics

Antenatal corticosteroid therapy to enhance fetal lung maturity in threatened preterm delivery has a number of non-pulmonary side-effects, both beneficial and undesirable. This review focuses on the short-term (transient) effects of betamethasone and dexamethasone on aspects of fetal circulation and behaviour which are used clinically as markers of fetal well-being. We summarise the effects observed, discuss the proposed underlying mechanisms, and emphasise the consequences for clinical decision-making. Recommendations are given to optimise medical care and to minimise the risk of unwarranted iatrogenic preterm delivery.

Medications in pregnancy and lactation: Part 2. Drugs with minimal or unknown human teratogenic effect

This is the second of a two-part series on the use of medication during pregnancy and lactation. Pregnancy risk factors together with an increased incidence of chronic diseases and the rise in mean maternal age predict an increase in medication use during gestation. However, as highlighted in the first installment of this series, relatively few medications have specifically been tested for safety and efficacy during pregnancy, and, therefore, responses to those inquiries can be uninformed and inaccurate. Whereas the first installment provided new insight into the nature of medications with known human teratogenic effects, this part concentrates on drugs with minimal or no known human teratogenic effect. It is important that clinicians become familiar with all of the aspects of the drugs they prescribe, in addition to the controversies surrounding them, through consultation with maternal-fetal medicine specialists and through references and Web sites providing up-to-date information in an effort to promote safer prescribing practices.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted the data independently.

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Brain Damage to the Survivor within 30 min of Co-Twin Demise in Monochorionic Twins

Single fetal death in a twin pregnancy in the late second or early third trimester is associated with significant morbidity and mortality rate in the surviving co-twin, especially in monochorionic twin pregnancies. The common causes are twin-to-twin transfusion syndrome, chromosomal abnormalities, and congenital anomalies of the fetus or anomalies of the umbilical cord-placenta. Here we report a case of monochorionic twin pregnancy in which one fetus had a single umbilical artery (SUA) while the co-twin had two umbilical arteries. The twin with SUA died in utero at the 30th week of gestation and the other fetus was delivered by cesarean section immediately due to fetal distress diagnosed by cardiotocography. Disseminated intravascular coagulation and multicystic encephalomalacia have been observed in the surviving neonate. This case and review of the literature suggest that neurologic complication rates are also increased in monochorionic twin pregnancies with single fetal demise despite the immediate delivery as in our case.

[Preterm corticosteroid therapy and fetal immobility. Case report]

We report a case of fetal immobility following antenatal corticosteroid therapy administered to women in thirty weeks at risk of preterm labor. The short-term side effect of corticosteroid, a decrease in fetal heart rate variation are well known. This case report presents the difficulty of therapy choice in front of fetal immobility and acute fetal distress. We chose a medical supervision. A review of the literature suggests other criteria, such as Doppler of umbilical artery, which could help therapeutical choice.

Glucocorticoid administration in antiemetic therapy: is it safe?

BACKGROUND

Although glucocorticoids are often used in cancer therapy, in particular to enhance the effectiveness of antiemetic therapy, they have been associated with impaired tumor apoptosis and an increased frequency of metastases in some reports. The current study aimed to determine whether glucocorticoid treatment had an adverse effect on outcomes in patients with ovarian carcinoma.

METHODS

Records of patients with ovarian carcinoma who were scheduled to receive at least six courses of systemic chemotherapy were reviewed. Patients were grouped into those who had or had not received corticosteroid medication as a part of general antiemetic prophylaxis before chemotherapy, and details of hematologic parameters during treatment and disease recurrence-free and overall survival were recorded.

RESULTS

Altogether, 245 patients with ovarian carcinoma had received chemotherapy. Of these, 62 had been given concurrent glucocorticoid treatment and 183 had not. The two patient groups were well balanced with respect to disease stage and other prognostic factors. Kaplan-Meier analyses showed no significant differences in survival between the groups. Patients who received glucocorticoid treatment had significantly higher leukocyte values in the days immediately after chemotherapy, higher nadir leukocyte values, and higher counts before subsequent courses of chemotherapy (P < 0.01; Levene test, t test) compared with patients who did not receive glucocorticoid treatment. As a result, the initial treatment targets were achieved significantly more often in the glucocorticoid group (P = 0.007; chi-square test).

CONCLUSIONS

There was no evidence that glucocorticoid treatment had a negative effect on outcomes in these patients. Glucocorticoids may exert protective effects on the bone marrow.

Short-Term Outcomes in Low Birth Weight Infants Following Antenatal Exposure to Betamethasone Versus Dexamethasone

OBJECTIVE

To assess the incidence of short-term outcomes of low birth weight infants (</= 1,750 g) exposed prenatally to either dexamethasone or betamethasone.

METHODS

We retrospectively analyzed a cohort comprising 550 infants who were born alive at our center during the period January 1999 through December 2001, who weighed 1,750 g or less at birth, and who were exposed to prenatal steroid treatment. We compared brain ultrasound findings, such as intraventricular hemorrhage and cystic periventricular leukomalacia (PVL), as well as other clinical findings, including respiratory distress syndrome (RDS), necrotizing enterocolitis, retinopathy of prematurity, and bronchopulmonary dysplasia, for all premature infants whose mothers received either dexamethasone (from January 1, 1999 to June 30, 2000, n = 263) or betamethasone (July 1, 2000 to December 31, 2001, n = 287).

RESULTS

Patient characteristics (mothers and infants) were the same in both groups, with the exception of the number of steroid courses administered, the number of women with premature rupture of membranes (defined as > 24 hours), and the number of women who had received tocolysis. No significant difference was found between the 2 groups with respect to intraventricular hemorrhage and cystic PVL frequencies. No significant differences were found in the incidence of short-term outcomes examined, despite the fact that the dexamethasone group was exposed to a statistically significantly greater number of courses than the betamethasone group.

CONCLUSION

There seem to be no advantages to maternal antenatal treatment with betamethasone compared with dexamethasone in reducing the risk of PVL in low birth weight (</= 1,750 g) infants. Both drugs have the same effect on all short-term outcome parameters checked.

The effects of antenatal betamethasone administration on fetal heart rate and behaviour depend on gestational age

OBJECTIVE

We previously reported decreases in fetal heart rate (FHR) variability and body and breathing movements after maternal betamethasone administration. We now test the hypothesis that fetal responsiveness to betamethasone depends on the gestational age at which glucocorticoid therapy is started.

DESIGN OF THE STUDY

1-h recordings of FHR (n=350) and fetal movements (n=310) made during a 5-day period (days 0-4) were available for analysis. The recordings had been obtained from 63 pregnant women at high risk for preterm delivery who received betamethasone (two doses of 12 mg 24 h apart) between 26 and 34 weeks' gestational age (wGA). The response to betamethasone, i.e. the direction and magnitude of change in FHR and movement parameters compared with baseline (day 0), was studied in relation to gestational age at drug administration.

RESULTS

Fetuses exposed to betamethasone at 29-34 wGA showed a decrease in FHR on day 1 (indicative of baroreceptor reflex), and reduced breathing activity and prolonged episodes of quiescence with a concomitant decrease in body movements on days 1 and 2. However, these changes were not observed if betamethasone administration occurred at 26-28 wGA. Betamethasone-induced reductions in FHR variability were similar in young and older fetuses.

CONCLUSIONS

Age-related differential responsiveness to betamethasone was found for all studied fetal processes (body and breathing movements, FHR, and quiescence), except FHR variability. Our results suggest ontogenic changes in the mechanisms presumed to underlie these processes (glucocorticoid receptor (GR) maturation, cardiovascular and neuro-endocrine development).