Do we use too much antenatal betamethasone?

Antenatal corticosteroids and neurodevelopmental outcomes in late preterm births

OBJECTIVES

Antenatal corticosteroids (ACS) decrease neonatal mortality and morbidity among preterm neonates, yet there has been concern regarding their long-term safety. We hypothesised that potential long-term adverse effects of ACS may be observed among infants born during the late preterm period (LPT, 34^0/7-36^6/7 weeks of gestation), when the benefits of ACS are subtle.

DESIGN

Population-based, retrospective cohort.

SETTING

Ontario, Canada, between 2006 and 2011.

PATIENTS

All live singleton infants born during the LPT period with a minimum 5-year follow-up.

INTERVENTIONS

Exposure to ACS prior to 34^0/7 weeks of gestation.

MAIN OUTCOME MEASURES

Suspected neurocognitive disorder, audiometry testing or visual testing.

RESULTS

Overall, 25 668 infants were eligible for analysis, of whom 2689 (10.5%) received ACS. Infants in the ACS group had lower mean birth weight and higher rates of birth weight <10th percentile, neonatal resuscitation and neonatal intensive care unit admission. At 5 years of age, ACS exposure was associated with an increased risk of suspected neurocognitive disorder (adjusted HR (aHR) 1.12, 95% CI 1.05 to 1.20), audiometry testing (aHR 1.20, 95% CI 1.10 to 1.31) and visual testing (aHR 1.06, 95% CI 1.01 to 1.11).

CONCLUSION

In children born during the LPT period, exposure to ACS prior to 34^0/7 weeks of gestation is associated with an increased utilisation of the healthcare system related to audiometry and visual testing and suspected neurocognitive disorders by 5 years of age.

Optimal antenatal corticosteroid exposure in women with history of preterm birth and asymptomatic short cervical length

BACKGROUND

A proposed benefit of cervical length assessment after 24 weeks' gestation in women with a history of preterm birth is to aid in the timing of antenatal corticosteroids in otherwise asymptomatic women.

OBJECTIVE

We sought to investigate whether the use of an ultrasonographic short cervical length as an indication for antenatal corticosteroids in asymptomatic women results in optimal exposure compared with women receiving antenatal corticosteroids for preterm labor symptoms.

STUDY DESIGN

Retrospective cohort study of all women with a previous spontaneous preterm birth and a singleton gestation who underwent serial cervical length assessment at a large academic tertiary medical center from 2011 to 2016. Patients were included in the analysis if they received antenatal corticosteroids for either an asymptomatic short cervical length or symptoms of preterm labor. The primary outcome was optimal antenatal corticosteroids exposure (latency to delivery of ≤7 days).

PROPOSED CHANGE IN RESULTS

Poisson regression with robust error variance was used to calculate incidence rate ratios (IRR) and confidence intervals (CI) for primary and secondary outcomes adjusting for primary and secondary outcomes adjusting for race, earliest previous preterm birth, and current cerclage.

RESULTS

There were 287 women meeting inclusion criteria, among whom 166 (57.8%) received antenatal corticosteroids for a short cervical length and 121 (42.2%) for preterm labor symptoms. Women who received antenatal corticosteroids for a short cervical length were less likely to have optimal exposure (1.2% vs 19.0%; incidence rate ratios, 0.06; confidence interval, 0.02-0.27) compared with women with preterm labor symptoms. They were also more likely to have exposure with eventual term delivery (43.2% vs 33.4%; incidence rate ratios, 1.6; confidence interval, 1.2-2.0). Importantly, women who received antenatal corticosteroids for a short cervical length were significantly less likely to receive either an initial or rescue antenatal corticosteroids course within 7 days of a preterm delivery of less than 34 weeks' gestation (42.9% vs 76.9%; incidence rate ratios, 0.52; confidence interval, 0.35-0.75).

CONCLUSION

Women with a previous preterm birth who receive antenatal corticosteroids for an asymptomatic short cervical length are less likely to have optimal exposure than women with symptoms of preterm labor. These data challenge the practice of cervical length surveillance for the sole indication of timing antenatal corticosteroids administration.

No. 364-Antenatal Corticosteroid Therapy for Improving Neonatal Outcomes

OBJECTIVE

To assess the benefits and risks of antenatal corticosteroid therapy for women at risk of preterm birth or undergoing pre-labour Caesarean section at term and to make recommendations for improving neonatal and long-term outcomes.

OPTIONS

To administer or withhold antenatal corticosteroid therapy for women at high risk of preterm birth or women undergoing pre-labour Caesarean section at term.

OUTCOMES

Perinatal morbidity, including respiratory distress syndrome, intraventricular hemorrhage, bronchopulmonary dysplasia, infection, hypoglycemia, somatic and brain growth, and neurodevelopment; perinatal mortality; and maternal morbidity, including infection and adrenal suppression.

INTENDED USERS

Maternity care providers including midwives, family physicians, and obstetricians.

TARGET POPULATION

Pregnant women.

EVIDENCE

Medline, PubMed, Embase, and the Cochrane Library were searched from inception to September 2017. Medical Subject Heading (MeSH) terms and key words related to pregnancy, prematurity, corticosteroids, and perinatal and neonatal mortality and morbidity were used. Statements from professional organizations including that of the National Institutes of Health, the American College of Obstetricians and Gynecologists, the Society for Maternal Fetal Medicine, the Royal College of Obstetricians and Gynaecologists, and the Canadian Pediatric Society were reviewed for additional references. Randomized controlled trials conducted in pregnant women evaluating antenatal corticosteroid therapy and previous systematic reviews on the topic were eligible. Evidence from systematic reviews of non-experimental (cohort) studies was also eligible.

VALIDATION METHODS

This Committee Opinion has been reviewed and approved by the Maternal-Fetal Medicine Committee of the SOGC and approved by SOGC Council.

BENEFITS, HARMS, AND/OR COSTS

A course of antenatal corticosteroid therapy administered within 7 days of delivery significantly reduces perinatal morbidity/mortality associated with preterm birth between 24 + 0 and 34 + 6 weeks gestation. When antenatal corticosteroid therapy is given more than 7 days prior to delivery or after 34 + 6 weeks gestation, the adverse effects may outweigh the benefits. Evidence on long-term effects is scarce, and potential neurodevelopment harms are unquantified in cases of late preterm, term, and repeated exposure to antenatal corticosteroid therapy.

GUIDELINE UPDATE

Evidence will be reviewed 5 years after publication to evaluate the need for a complete or partial update of the guideline. If important evidence is published prior to the 5-year time point, an update will be issued to reflect new knowledge and recommendations.

SPONSORS

The guideline was developed with resources provided by the Society of Obstetricians and Gynaecologists of Canada with support from the Canadian Institutes of Health Research (APR-126338).

SUMMARY STATEMENTS

RECOMMENDATIONS: Gestational Age Considerations Agents, Dosage, Regimen, and Target Timing Subpopulations and Special Consideration.

Neurodevelopmental disorders among term infants exposed to antenatal corticosteroids during pregnancy: a population-based study

OBJECTIVE

An increasing proportion of fetuses are exposed to antenatal corticosteroids (ACS). Despite their immediate beneficial effects, the long-term safety of ACS has been an ongoing source of concern. In the current study, we assessed the likelihood of neurodevelopmental problems among term infants exposed to ACS earlier in pregnancy compared with non-exposed term infants.

DESIGN

Retrospective cohort study (2006-2011). Median duration of follow-up was 7.8 (IQR 6.4-9.2) years.

SETTING

Population-based study, Ontario, Canada.

PARTICIPANTS

All live singleton infants born at term (≥37^0/7 weeks gestation) (n=529 205).

EXPOSURE

ACS during pregnancy.

PRIMARY AND SECONDARY OUTCOME MEASURES

A composite of diagnostic or billing codes reflecting proven or suspected neurodevelopmental problems during childhood including audiometry testing, visual testing or physician service claim with a diagnosis code related to a suspected neurocognitive disorder.

RESULTS

At 5 years of age, the cumulative rate for the primary outcome was higher among infants exposed to ACS compared with non-exposed infants: 61.7% (3346/5423) vs 57.8% (302 520/523 782), respectively (p<0.001; number needed to harm (NNH)=25, 95% CI 19 to 38; adjusted HR (aHR) 1.12, 95% CI 1.08 to 1.16). Similar findings were observed for each of the individual components of the primary outcome: 15.3% vs 12.7% for audiometry testing (p<0.001; NNH=39, 95% CI 29 to 63; aHR 1.18, 95% CI 1.11 to 1.25); 45.4% vs 43.5% for visual testing (p=0.006; NNH=54, 95% CI 31 to 200; aHR 1.08, 95% CI 1.04 to 1.12) and 25.8% vs 21.6% for suspected neurocognitive disorder (p<0.001; NNH=24, 95% CI 19 to 33; aHR 1.16, 95% CI 1.10 to 1.21).

CONCLUSIONS

We found an association among term infants between exposure to ACS during pregnancy and healthcare utilisation during childhood related to suspected neurocognitive and neurosensory disorders.

Use of Antenatal Corticosteroid Therapy: A Descriptive Study of Clinical Practice Trends

OBJECTIVES

Antenatal corticosteroids (ACS) received within 7 days of delivery reduce perinatal morbidity and mortality associated with preterm birth. We aimed to describe the trends of ACS administration over the last decade.

METHODS

A cohort study of women who received ACS in 2006, 2011, and 2016 at the CHU de Québec-Université Laval was conducted. The indication, GA at ACS, and GA at birth, were collected in 150 women randomly selected in each studied year. Our main endpoints were the frequency of ACS administration within 7 days of delivery and between 48 hours and 7 days before delivery.

RESULTS

We included 447 women who received ACS at a median GA of 31.4 (range 23.6-39.0) weeks. No women received ACS after 35 weeks in 2006 and 2011. The administration of ACS for indicated delivery between 35 and 39 weeks occurred only in the last study period. Among women for whom ACS was initiated before 35 weeks, 31% received ACS in the 7 days before delivery, and only 13% received ACS between 48 hours and 7 days before birth (varying from 12% to 16%, P = 0.57). Threatened preterm labour or short cervix were the indication for ACS initiation in 39% women who received ACS before 35 weeks, but less than 5% of these women delivered between 2 and 7 days and more than 90% delivered after 14 days.

CONCLUSIONS

Administration of ACS remains suboptimal. Threatened preterm labour and short cervix are poorly related to optimal use of ACS therapy.

N° 364 - La Corticothérapie Prénatale Pour Améliorer Les Issues Néonatales

OBJECTIF

Évaluer les avantages et les risques de la corticothérapie prénatale chez les femmes qui présentent un risque d'accouchement prématuré ou qui subissent une césarienne à terme avant début de travail, et formuler des recommandations visant l'amélioration des issues néonatales et des issues à long terme.

OPTIONS

Administrer ou ne pas administrer une corticothérapie prénatale aux femmes qui présentent un risque élevé d'accouchement prématuré ou qui subissent une césarienne avant travail à terme. RéSULTATS: Morbidité périnatale, notamment le syndrome de détresse respiratoire, l'hémorragie intraventriculaire, la dysplasie bronchopulmonaire, l'infection, l'hypoglycémie, ainsi que les troubles de la croissance somatique et cérébrale et du neurodéveloppement; mortalité périnatale; et morbidité maternelle, notamment l'infection et la suppression surrénalienne.

UTILISATEURS CIBLES

Fournisseurs de soins de maternité, notamment les sages-femmes, les médecins de famille et les obstétriciens.

POPULATION CIBLE

Femmes enceintes. ÉVIDENCE: Nous avons interrogé les bases de données Medline, PubMed et Embase ainsi que la Bibliothèque Cochrane, de leur création au mois de septembre 2017. Nous nous sommes servis de Medical Subjet Headings (MeSH) et de mots clés en lien avec la grossesse, la prématurité, les corticostéroïdes ainsi que la mortalité et la morbidité périnatales et néonatales. Nous avons également consulté les déclarations d'organismes professionnels tels que les National Institutes of Health, l'American College of Obstetricians and Gynecologists, la Society for Maternal-Fetal Medicine, le Royal College of Obstetricians and Gynaecologists et la Société canadienne de pédiatrie pour obtenir des références additionnelles. Les essais cliniques randomisés évaluant la corticothérapie prénatale menés sur des femmes enceintes et les revues systématiques antérieures sur le sujet étaient admissibles, tout comme les données venant de revues systématiques d'études non expérimentales (études de cohorte).

VALEURS

La présente opinion de comité a été révisée et approuvée par le Comité de médecine fœto-maternelle de la SOGC, et approuvée par le Conseil de la SOGC. AVANTAGES, INCONVéNIENTS ET COûTS: L'administration d'une corticothérapie prénatale dans les sept jours précédant l'accouchement réduit significativement la morbidité et la mortalité périnatales associées à la naissance prématurée survenant entre 24+0 et 34+6 semaines de grossesse. Si la corticothérapie prénatale est administrée plus de sept jours avant l'accouchement ou après 34+6 semaines de grossesse, les effets indésirables peuvent surpasser les avantages. Les données probantes sur l'impact à long terme de la corticothérapie prénatale sont rares. Par ailleurs, les effets neurodéveloppementaux néfastes potentiels de l'exposition répétée à la corticothérapie prénatale ou de l'administration de corticostéroïdes en période préterme tardive ou à terme n'ont pas été quantifiés. MIS-à-JOUR à LA DIRECTIVE: Une revue des données probantes sera menée cinq ans après la publication de la présente directive clinique afin d'évaluer si une mise à jour complète ou partielle s'impose. Si de nouvelles données probantes importantes sont publiées avant la fin de ces cinq ans, une mise à jour tenant compte des nouvelles connaissances et recommandations sera publiée.

COMMANDITAIRES

La présente directive clinique a été élaborée à l'aide de ressources fournies par la Société des obstétriciens et gynécologues du Canada et avec l'appui des Instituts de recherche en santé du Canada (APR-126338). MOTS CLéS: Corticothérapie prénatale, maturation fœtale, prématurité, période préterme tardive, césarienne avant travail DÉCLARATION SOMMAIRES: RECOMMANDATIONS: Considérations relatives à l'âge gestationnel.

Antenatal corticosteroid therapy: current strategies and identifying mediators and markers for response

Landmark early work has led to the nearly universal use of antenatal corticosteroids to accelerate fetal lung maturity with pregnancies complicated by impending preterm birth. Antenatal corticosteroids clearly reduce respiratory morbidity, death, and other adverse neonatal outcomes. Limited pregnant human pharmacokinetic data and some animal data give clinicians some information as to the behavior of the drug in the body. However, there is controversy about the type, amount, and frequency of steroid to use for this therapy. This review article summarizes the history, clinical use, and pharmacology of antenatal steroids. In addition, the review highlights some potential mediators of steroid response and current research strategies aimed at possible optimization of this therapy.