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

Prognosis comparison between small cell carcinoma of ovary and high-grade serous ovarian cancer: A retrospective observational cohort study

BACKGROUND

Small cell carcinoma of ovary (SCCO) is a rare and aggressive cancer primarily reported in the form of case reports. Due to limited epidemiological and prognostic analyses based on large populations, SCCO has varied considerably without prognostic models and a recognized first-line treatment strategy. The study aimed to compare the clinical characteristics, treatment methods, and prognosis of SCCO and high-grade serous ovarian cancer (HGSOC), the most prevalent subtype of ovarian cancer, in a large sample and develop a predictive model for these two subtypes.

METHODS

Data from the Surveillance, Epidemiology, and End Results program were analyzed for patients with SCCO or HGSOC from 2000 to 2017. Clinical, demographic, and treatment characteristics were compared between the two groups. Propensity-score matching, Cox risk regression analysis, and Kaplan-Meier survival curves were used to assess the data. Finally, a nomogram was developed to predict the patient survival time.

RESULTS

A total of 32,185 women, including 31,979 (99.4%) diagnosed with HGSOC and 206 (0.6%) diagnosed with SCCO, were identified. Age ≤ 51 years, single, median house income less than $70,000, early stage, and unilateral disease were more common characteristics of patients with SCCO than those with HGSOC. Patients with SCCO were more likely to receive radiotherapy (6.8% vs. 0.8%, p <0.001) and have tumors ≥ 141 mm (38.3% vs. 9.7%, p <0.001) than patients with HGSOC. The independent risk factors for SCCO patients included older age at diagnosis, advanced stage, surgery, radiotherapy, chemotherapy, larger tumor size, and bilateral tumor. Overall and cancer-specific survival rates were significantly lower for SCCO than more malignant HGSOC. Prognostic models and nomograms had been constructed to predict the individual survival rates of patients with SCCO and HGSOC.

CONCLUSION

Patients with SCCO presented with the early-stage disease more frequently than patients with HGSOC and had decreased overall and cancer-specific survival rates.

Precision caffeine therapy for apnea of prematurity and circadian rhythms: New possibilities open up

Caffeine is the globally consumed psychoactive substance and the drug of choice for the treatment of apnea of prematurity (AOP), but its therapeutic effects are highly variable among preterm infants. Many of the molecular underpinnings of the marked individual response have remained elusive yet. Interestingly, the significant association between Clock gene polymorphisms and the response to caffeine therapy offers an opportunity to advance our understanding of potential mechanistic pathways. In this review, we delineate the functions and mechanisms of human circadian rhythms. An up-to-date advance of the formation and ontogeny of human circadian rhythms during the perinatal period are concisely discussed. Specially, we summarize and discuss the characteristics of circadian rhythms in preterm infants. Second, we discuss the role of caffeine consumption on the circadian rhythms in animal models and human, especially in neonates and preterm infants. Finally, we postulate how circadian-based therapeutic initiatives could open new possibilities to promote precision caffeine therapy for the AOP management in preterm infants.

Identification of glucocorticoid receptors as potential modulators of parasympathetic and sympathetic neurons within rat intracardiac ganglia

Background

Emerging evidences indicate that glucocorticoid receptors (GR) play a regulatory role in cardiac function, particularly with regard to the autonomic nervous system. Therefore, this study aimed to demonstrate the expression and the precise anatomical location of GR in relation to the parasympathetic and sympathetic innervations of the heart.

Methods

The present study used tissue samples from rat heart atria to perform conventional reverse-transcriptase polymerase chain reaction (RT-PCR), Western blot, and double immunofluorescence confocal analysis of GR with the neuronal markers vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP) as well as the mineralocorticoid receptor (MR).

Results

Double immunofluorescence labeling revealed that GRs were co-expressed with VAChT in parasympathetic principal neuronal somata and nerve terminals innervating atrium. Also, GR colocalized with the sympathetic neuronal marker TH in a cluster of small intensely fluorescent (SIF) cells, on intracardiac nerve terminals and in the atrial myocardium. GR immunoreactivity was scarcely identified on CGRP-immunoreactive sensory nerve terminals. Approximately 20% of GR immunoreactive neuronal somata co-localized with MR. Finally, conventional RT-PCR and Western blot confirmed the presence of GR and MR in rat heart atria.

Conclusion

This study provides evidence for the existence of GR predominantly on cardiac parasympathetic neurons and TH-immunoreactive SIF cells suggesting a functional role of cardiac GR on cardiovascular function by modulation of the cardiac autonomic nervous system.

No. 197a-Fetal Health Surveillance: Antepartum Consensus Guideline

OBJECTIVE

This guideline provides new recommendations pertaining to the application and documentation of fetal surveillance in the antepartum period that will decrease the incidence of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention. Pregnancies with and without risk factors for adverse perinatal outcomes are considered. This guideline presents an alternative classification system for antenatal fetal non-stress testing to what has been used previously. This guideline is intended for use by all health professionals who provide antepartum care in Canada.

OPTIONS

Consideration has been given to all methods of fetal surveillance currently available in Canada.

OUTCOMES

Short- and long-term outcomes that may indicate the presence of birth asphyxia were considered. The associated rates of operative and other labour interventions were also considered.

EVIDENCE

A comprehensive review of randomized controlled trials published between January 1996 and March 2007 was undertaken, and MEDLINE and the Cochrane Database were used to search the literature for all new studies on fetal surveillance antepartum. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care (Table 1).

SPONSOR

This consensus guideline was jointly developed by the Society of Obstetricians and Gynaecologists of Canada and the British Columbia Perinatal Health Program (formerly the British Columbia Reproductive Care Program or BCRCP) and was partly supported by an unrestricted educational grant from the British Columbia Perinatal Health Program. RECOMMENDATION 1: FETAL MOVEMENT COUNTING: RECOMMENDATION 2: NON-STRESS TEST: RECOMMENDATION 3: CONTRACTION STRESS TEST: RECOMMENDATION 4: BIOPHYSICAL PROFILE: RECOMMENDATION 5: UTERINE ARTERY DOPPLER: RECOMMENDATION 6: UMBILICAL ARTERY DOPPLER.

Increased right ventricular power and ductal characteristic impedance underpin higher pulmonary arterial blood flow after betamethasone therapy in fetal lambs

BACKGROUND

The glucocorticosteroid betamethasone is routinely administered prior to anticipated preterm birth to enhance lung maturation. While betamethasone also increases fetal pulmonary blood flow and reduces pulmonary vascular resistance (PVR), we investigated whether alterations in right ventricular (RV) function and ductal characteristic impedance (Z_c) additionally contributed to rises in pulmonary flow.

METHODS

Anesthetized preterm fetal lambs with (n = 10) or without (n = 8) betamethasone pretreatment were instrumented with a pulmonary trunk micromanometer and ductus arteriosus and left pulmonary artery (PA) flow probes to calculate Z_c, and obtain RV output and hydraulic power.

RESULTS

Betamethasone (1) increased systolic and pulse arterial pressures (P ≤ 0.04), heart rate (P = 0.02), and lowered PVR (P = 0.04), (2) increased mean (P = 0.008) and systolic (P = 0.004), but not diastolic PA flow or PA Z_c, (3) increased ductal Z_c (P < 0.05), but not ductal flow, (4) increased RV output (P = 0.03) and the proportion of PT flow distributed to the lungs (P = 0.02), and (5) increased RV power (P ≤ 0.002).

CONCLUSION

An increased fetal PA blood flow after betamethasone therapy was confined to the systole and underpinned not only by decreased PVR, but also greater RV power and preferential distribution of an augmented RV systolic outflow to the lungs due to higher ductal Z_c.

Glucocorticoids, antenatal corticosteroid therapy and fetal heart maturation

Glucocorticoids are essential in mammals to mature fetal organs and tissues in order to survive after birth. Hence, antenatal glucocorticoid treatment (termed antenatal corticosteroid therapy) can be life-saving in preterm babies and is commonly used in women at risk of preterm birth. While the effects of glucocorticoids on lung maturation have been well described, the effects on the fetal heart remain less clear. Experiments in mice have shown that endogenous glucocorticoid action is required to mature the fetal heart. However, whether the potent synthetic glucocorticoids used in antenatal corticosteroid therapy have similar maturational effects on the fetal heart is less clear. Moreover, antenatal corticosteroid therapy may increase the risk of cardiovascular disease in adulthood. Here, we present a narrative review of the evidence relating to the effects of antenatal glucocorticoid action on the fetal heart and discuss the implications for antenatal corticosteroid therapy.

Reduced short-term variation following antenatal administration of betamethasone: Is reduced fetal size a predisposing factor?

OBJECTIVE

To assess the association between fetal size and the incidence of reduced short-term variability (STV) following bethametasone administration for fetal lung maturity.

STUDY DESIGN

This was a retrospective, multicenter, cohort study conducted in two Tertiary University Units. Only uncomplicated singleton pregnancies admitted for threatened preterm labor between 26 and 34 weeks and submitted to betamethasone for fetal lung maturity were included. Delivery occurring within 72h from betamethasone administration represented criteria for exclusion. Computerized cardiotocography was carried out on a daily basis. Cases were identified by persistently reduced STV, defined as <5th percentile for gestational age and lasting for at least 72h after the first dose of betamethasone. The primary outcome was estimated fetal weight (EFW) at ultrasound in fetuses with normal and in those with persistently reduced STV. Pregnancy outcomes were also evaluated.

RESULTS

Persistently reduced STV occurred in 33/405 of the included patients (8.1%). Compared to women with normal STV, those with persistently reduced STV had significantly lower EFW (1472±435 vs 1812±532g, p 0.04), lower birthweight (2353±635 vs 2857±796g, p<0.01) and earlier gestational age at delivery (35.1±4.2 vs 37.3±2.4weeks, p<0.01), whereas all the other variables including gestational age on admission were comparable.

CONCLUSIONS

Reduced STV following maternal betamethasone administration among appropriately grown fetuses seems to correlate with lower fetal size. Furthermore, fetuses with such abnormal response to steroids seem to carry a higher risk of perinatal complications, including lower birthweight and earlier gestational age at delivery.

Longitudinal progression of fetal short-term variation and average acceleration and deceleration capacity after antenatal maternal betamethasone application

OBJECTIVE

To analyze the effect of maternal betamethasone given for fetal lung maturation on fetal short-term variation (STV) and average acceleration and deceleration capacity (AAC/ADC). Both of these factors are calculated by phase-rectified signal averaging (PRSA) and represent new parameters to assess the fetal autonomic nervous system.

STUDY DESIGN

A longitudinal prospective study including 26 pregnant women at risk for preterm delivery was performed. Two injections of 12mg betamethasone were administered intramuscularly at a 24h interval for lung maturation. Cardiotocography recordings were performed at defined time intervals: day 0 (before the first injection) and days 1, 2, 4 after the first corticosteroid administration. AAC/ADC and STV were calculated.

RESULTS

An increase of all parameters (STV, AAC and ADC) was documented between day 0 and day 1. Between day 1 and day 2, all three indices were significantly reduced (p<0.05). STV declined by 19.8%, AAC by 10.1% and ADC by 14.8%. A normalization of these values was seen after 96h.

CONCLUSION

Similar to STV, AAC/ADC shows significant changes after maternal betamethasone administration. The corticosteroid-induced transient decrease of the levels needs to be taken into account in the assessment of the fetal status to avoid misinterpretation of these parameters.

Antenatal steroids: can we optimize the dose?

PURPOSE OF REVIEW

The beneficial effects of antenatal steroids in women at risk of preterm birth are evident. A dose of 24 mg appears sufficient, but there are insufficient data to recommend betamethasone or dexamethasone, a single steroid dose, the optimal interval between doses and repeated courses, the gestational age at which treatment is beneficial and the long-term effects of steroid treatment. This review addresses these aspects of antenatal steroid treatment.

RECENT FINDINGS

Although the 12-h and 24-h dosing intervals are equivalent with respect to prevention of respiratory distress syndrome, the former enables the completion of treatment in 50% more neonates delivered prematurely. Reducing the single steroid dose in patients at risk for premature birth reduces the associated maternal side effects. An inverse relationship has been demonstrated between the number of corticosteroid courses and foetal growth. The reduced size of exposed foetuses has been attributed to birth at earlier gestational ages and decreased foetal growth. Evidence suggests that antenatal exposure to synthetic glucocorticoids in term-born children has long-lasting effects, which may have important implications in the recommendation of steroids before elective caesarean at term.

SUMMARY

The short-term and long-term effects of the dosage regimen on the pregnant mother and foetus remain unclear.

Efficacy of betamethasone on the fetal motion and biophysical profile and amniotic fluid index in preterm fetuses

The term ofpreterm birth is used to define the premature neonates considering pregnancy age. In less than 34 week pregnancies, corticosteroids are prescribed to promote embryos' lung maturity. The presents study aimed at evaluating effects of betamethasone injection on feeling embryo motion by mother and index and biophysical profile in preterm pregnancies. In a descriptive-analytical study, 40 pregnant women with the pregnancy age of 30-34 weeks were evaluated. Embryo motion and index and biophysical profile of the amniotic fluid were checked before prescription of double dosage of muscular betamethasone (12 mg) at a 24 h time interval. The injection was repeated for 24 and 48 h after the first injection. The resulted outcomes were compared with those results related to before betamethasone injection. In this study, there was statistically meaningful relationship between embryo motions before injection of betamethasone and 12 h after its injection (p = 0.03). Also, there was a significant relationship between embryo motions 24 and 48 h after injection of betamethasone (p = 0.001). In other words, the embryo motions decreased 12 h after injection of betamethasone. They were improved 48 h after betamethasone injection. But, index and biophysical profile results of amniotic fluid were left unchanged. Application of betamethasone leads to evident but transient decrease in embryo motions. Although motion element of index and biophysical profile of amniotic fluid which is one of the tests used in evaluating the embryo health is fixed and normal, it can be concluded that injection of betamethasone may not affect embryo health.

Effect of antenatal betamethasone administration on neonatal cardiac autonomic balance

Beneficial effects of antenatal glucocorticoid treatment in pregnancies at risk for preterm delivery may entail long-term consequences for the establishment of sympathoadrenergic system balance. We analyzed the cardiac autonomic system activity in neonates with a single course of antenatal betamethasone (2 × 12 mg) treatment by calculating heart rate variability (HRV) time-domain parameters from 24 h ECG recordings and short-term frequency-domain parameters during infant active and resting states. In addition, resting and challenged salivary α-amylase levels were measured in 23 betamethasone-exposed neonates and compared with controls. Indicators for overall HRV (SDNN: p = 0.258; triangular index: p = 0.179) and sympathovagal balance [low- to high-frequency power (LF/HF): p = 0.82 (resting state)] were not significantly different in neonates of the betamethasone treatment group. Parameters mostly influenced by sympathetic activity [SD of the average of valid NN intervals (SDANN): p = 0.184 and SDs of all NN intervals (SDNNi): p = 0.784] and vagal tone [RMSSD: p = 1.0; NN50: p = 0.852; HF: p = 0.785 (resting state)] were unaltered. Resting α-amylase levels were not significantly different in the betamethasone treatment group (p = 0.304); however, α-amylase release after a neonatal challenge was slightly reduced (p = 0.045). Thus, cardiac autonomic balance seems to be preserved in neonates exposed to a single course of antenatal betamethasone treatment.

Does the anti-hypertensive drug clonidine affect the short-term variation in CTG recordings?

BACKGROUND

Cardiotocographic (CTG) recordings of the fetal heart remain standard obstetric practice among hypertensive women. Changes in the short-term variation (STV) in the fetal heart are often attributed to the effect of anti-hypertensive medications, regardless of the fact that this principle has never been validated.

AIM

To assess the STV of CTG recordings pre- and post- the anti-hypertensive medication, clonidine.

METHODS

Forty hypertensive pregnant women, already receiving the anti-hypertensive clonidine, were recruited. The CTGs were conducted pre- and post-dose administration. The CTGs were assessed by the Sonicaid Team® automated CTG analysis (Oxford Instruments, UK) to avoid CTG assessor bias. Baseline fetal heart rate (FHR) (delta change from pre- and post-dose) and STV were compared using spss v.14® utilising Student t-tests.

RESULTS

No statistical difference was found in the pre- and post-baseline FHRs (P = 0.48). The mean delta baseline heart rate before and after drug administration was -0.54 bpm. The STV of the CTGs recorded pre- and post-clonidine dose was also not affected by administration of the drug (P = 0.34). The mean delta STV before and after drug administration was 0.39 ms. Two women received betamethasone 12 mg intramuscularly within the 12-h period prior to CTG recordings to enhance fetal lung maturity. The mean STV for the fetuses of these women pre-drug was 4.8 ms and 13.2 ms post-administration. This was the largest delta seen in all STVs recorded in this dataset.

CONCLUSION

The anti-hypertensive drug clonidine does not alter baseline FHRs or affect the STV of the FHR in hypertensive pregnant women.

The effect of antenatal steroid treatment on fetal autonomic heart rate regulation revealed by fetal magnetocardiography (fMCG)

BACKGROUND

Steroid administration to accelerate fetal lung maturation reduces neonatal morbidity and mortality in the case of preterm delivery. Behavioral observations suggest effects on fetal cardiovascular regulation.

AIM

We hypothesize that beat to beat heart rate variability (fHRV) derived from fetal magnetocardiography (fMCG) will reveal a direct, acute steroidal effect on fetal autonomic heart rate regulation.

SUBJECTS

Eight patients between 29 and 34 weeks of gestation at risk for preterm birth who were treated with betamethasone (2x12 mg within 24 h).

STUDY DESIGN

Subjects were studied prior to the first and within 6 h after the second administration. Continuous fMCG was recorded with a 31-channel-SQUID biomagnetometer. Each dataset was processed by subtracting maternal cardiac artefacts and determining the time instants of the fetal heart beats. fHRV analysis was applied to periods of fetal quiescence of 4 min length.

OUTCOME MEASURES

We compared fHRV prior versus post steroid administration.

RESULTS

Steroid exposure reduced all parameters of overall fHRV significantly. The fHRV parameters representing short term variability remained unaffected. Mean fetal heart rate significantly decreased. The complexity of the heart rate patterns increased.

CONCLUSION

Our results suggest an acute shift in the sympatho-vagal balance of fetuses exposed to betamethasone in utero toward sympathetic suppression.

Antenatal glucocorticoid therapy increase cardiac alpha-enolase levels in fetus and neonate rats

AIMS

Antenatal glucocorticoid therapy has been shown to prevent acute diseases including infant respiratory distress syndrome and reduce mortality, although little is known about the effects on cardiac function-related proteins in the fetus or neonate. We investigated whether cardiac function-related proteins were altered in cardiac tissues of fetuses and neonates born to pregnant rats treated by glucocorticoid.

MAIN METHODS

Dexamethasone (DEX) was administered to pregnant rats for 2 days on day 17 and 18 or day 19 and 20 of gestation to simulate antenatal DEX therapy, and cardiac tissues of 19- and 21-day fetuses and 1-, 3-, and 5-day neonates were analyzed using a proteomic technique with liquid chromatography-mass spectrometry/mass spectrometry.

KEY FINDINGS

The identified five proteins; alpha-enolase, creatine kinase-M type, beta-tubulin, troponin T, and ATP synthase beta-chain, were significantly increased in fetal cardiac tissues with DEX administration. We observed that significant increase of alpha-enolase in the 19-day fetuses by DEX using Western blotting and immunohistochemistry. ATP and cAMP levels were also increased in the fetal heart tissue. In addition, pyruvate levels were significantly increased in the fetus groups by DEX.

SIGNIFICANCE

These results suggest that increased alpha-enolase may contribute to acceleration of glycolysis in the preterm heart.

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.

Use of tocolytics: what is the benefit of gaining 48 hours for the fetus?

Preterm birth remains one of the serious problems in perinatal medicine and is associated with an increased risk of neonatal complications and long-term morbidity. Although each day that delivery is delayed between 22 and 28 weeks of gestation increases survival by 3%, since most spontaneous preterm labour occurs between 28 and 34 weeks of gestation, this is of secondary concern; the primary goal of delay is to improve the function of certain systems in the fetus and to balance the risks of a hostile intrauterine environment with the complications of extrauterine preterm life. Although there is a lack of definitive evidence that tocolytic drugs improve outcome following spontaneous preterm labour and preterm birth, there is ample evidence that tocolysis delays delivery for long enough to permit administration of a complete course of antepartum glucocorticoids and to facilitate in utero transfer to a tertiary care unit where neonatal care will be optimal. Both these measures have been associated with improved outcomes; antepartum glucocorticoids reduce the incidence of respiratory distress syndrome, intraventricular haemorrhage, periventricular leucomalacia and necrotising enterocolitis, and in utero transfer is associated with decreased morbidity and mortality and less hospital-based intervention compared with postnatal transportation. Consequently, women who are more likely to benefit from tocolysis are those at early gestational ages, those needing transfer to a hospital that can provide neonatal intensive care and those who have not yet received a full course of antepartum glucocorticosteroids. In these cases, delaying labour for at least 48 hours with drugs such as atosiban should be considered, since it offers clear advantages for the fetus.

Short-term (0-48 h) effects of maternal betamethasone administration on fetal heart rate and its variability

The short-term (0-48 h) effects of maternal betamethasone administration on computerized fetal heart rate (FHR) parameters were studied in 36 pregnancies at increased risk for preterm delivery. FHR was recorded for 90 min immediately before the start of betamethasone treatment and again at 6-h intervals during the next 48 h. Multiple linear regression models were used to assess the possible effects on FHR parameters of gestational age, time of day, clinical indication for treatment, and use of tocolytic drugs. Within 12 h after the start of treatment, significant increases occurred in FHR accelerations, and short- and long-term FHR variability (36%, 28%, and 22%, respectively), whereas basal FHR showed a 5% decrease. FHR variability was decreased by 10% at 42-48 h. The observed changes were more pronounced in older (29-33 wk of gestation) compared with younger fetuses (25-28 wk of gestation). Decelerations occurred only in 4 out of 11 compromised fetuses during betamethasone therapy. We conclude that there are significant changes in FHR parameters during the first 48 h after betamethasone administration. These changes are transient in normal fetuses. However, the compromised fetus may be adversely affected by betamethasone.

Corticosteroids, pregnancy, and HELLP syndrome: a review

Corticosteroids are potent antiinflammatory and immunosuppressive drugs, which are used in the treatment of a wide range of medical disorders. During pregnancy, several corticosteroids are administered for maternal as well as fetal reasons. Prednisone and prednisolone show limited transplacental passage and are thus used for treatment of maternal disease. Dexamethasone and betamethasone, drugs that can easily cross the placenta, are more suitable for fetal indications. During the last decade, administration of corticosteroids was introduced in the treatment of hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome), a severe form of preeclampsia unique to human pregnancy. Several randomized, controlled trials as well as other prospective and retrospective studies have been performed to investigate this beneficial effect of corticosteroids on biochemical measures and clinical signs. This review discusses the characteristics of corticosteroids in humans and details the use of corticosteroids during pregnancy. A review of literature on the effect of corticosteroids on HELLP syndrome is given and possible mechanisms of action are discussed.

Cardiovascular and endocrine effects of a single course of maternal dexamethasone treatment in preterm fetal sheep

OBJECTIVE

To determine the effects of a single course of maternally administered dexamethasone on preterm fetal sheep in utero.

DESIGN

Prospective randomised controlled trial.

SETTING

University laboratory.

SAMPLE

Pregnant sheep at 0.7 of gestation.

METHODS

Pregnant ewes at 103 days of pregnancy (term = 147 days) were given two intramuscular injections of vehicle (n= 7) or 12 mg of dexamethasone (DEX; n= 8) 24 hours apart. Fetuses were continuously monitored for five days.

MAIN OUTCOME MEASURES

Fetal mean arterial blood pressure, carotid and femoral arterial blood flow and vascular resistance, heart rate, heart rate variability, fetal plasma cortisol and ACTH and fetal body movements.

RESULTS

DEX injections led to an acute increase in mean arterial blood pressure with a rise in carotid and femoral vascular resistance, a fall in femoral arterial blood flow, and a brief fall in fetal heart rate followed by significant tachycardia. From 24 hours after the injections, mean arterial blood pressure and vascular resistance returned to control values, however, a mild tachycardia [200 (3) vs 184 (4) bpm, P < 0.05] and loss of the circadian pattern of fetal heart rate variability persisted until the end of recording. Plasma ACTH and cortisol were markedly suppressed by DEX (P < 0.05), with values returning to control levels 32 and 72 hours after the first injection, respectively. There was no effect on basal fetal heart rate variability, body movements, carotid arterial blood flow, or the circadian pattern of fetal heart rate.

CONCLUSION

In contrast to previous experiments utilising direct fetal infusion of steroids, maternal administration of DEX was associated with only transient hypertension.

Effects of antenatal betamethasone administration on fetal heart rate and behavior in twin pregnancy

The efficacy of antenatal corticosteroid therapy in reducing the incidence of respiratory distress syndrome in twin pregnancy is controversial. The corticosteroid levels achieved with the current regimen might not be high enough to reach both siblings. In singleton fetuses, maternal betamethasone administration causes transient reductions in fetal heart rate (FHR), FHR variability, and body and breathing movements. We performed a prospective study to determine whether there are similar effects of betamethasone on FHR and behavior in preterm twin pregnancy and whether the effects occur similarly in both twin members. Eighteen women who were carrying twins received optimal corticosteroid treatment. Simultaneous recordings were made on twins before (day 0), during (days 1-2), and after (days 3-4) corticosteroid therapy using separate cardiotocography and ultrasound machines. Betamethasone administration was associated with significant transient decreases in basal FHR (day 1), FHR variability (days 2 and 3), and body and breathing movements (day 2). The overall changes in twins were similar to those previously found in singleton pregnancies. There was a high degree of association of response to betamethasone among individual members of twin pairs. The betamethasone-induced effects were unrelated to fetal sex, positioning, chorionicity, and discordance in size, but there was an effect of gestation on FHR. We conclude that the current regimen of antenatal corticosteroids used in preterm twin pregnancies results in observable physiologic and behavioral changes in twin pairs irrespective of their composition. This provides evidence that the achieved betamethasone levels are high enough to reach the compartment of either twin member.