Canadian SARS-CoV-2 serological survey using antenatal serum samples: a retrospective seroprevalence study.

BACKGROUND: Insufficient data on the rate and distribution of SARS-CoV-2 infection in Canada has presented a substantial challenge to the public health response to the COVID-19 pandemic. Our objective was to assess SARS-CoV-2 seroprevalence in a representative sample of pregnant people throughout Canada, across multiple time points over 2 years of the pandemic, to describe the seroprevalence and show the ability of this process to provide prevalence estimates. METHODS: This Canadian retrospective serological surveillance study used existing serological prenatal samples across 10 provinces over multiple time periods: Feb. 3-21, 2020; Aug. 24-Sept. 11, 2020; Nov. 16-Dec. 4, 2020; Nov. 15-Dec. 3, 2021; and results from the province of British Columbia during a period in which the SARS-CoV-2 B.1.1.529 (Omicron) variant was predominant, from Nov. 15, 2021, to June 11, 2022. Age and postal code administrative data allowed for comparison with concurrent polymerase chain reactivity (PCR)-positive results collected by Statistics Canada and the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) project. RESULTS: Seropositivity in antenatal serum as early as February 2020 indicates SARS-CoV-2 transmission before the World Health Organization's declaration of the pandemic. Seroprevalence in our sample of pregnant people was 1.84 to 8.90 times higher than the recorded concurrent PCR-positive prevalence recorded among females aged 20-49 years in November-December 2020. Overall seropositivity in our sample of pregnant people was low at the end of 2020, increasing to 15% in 1 province by the end of 2021. Seroprevalence among pregnant people in BC during the Omicron period increased from 5.8% to 43% from November 2021 to June 2022. INTERPRETATION: These results indicate widespread vulnerability to SARS-CoV-2 infection before vaccine availability in Canada. During the time periods sampled, public health tracking systems were under-reporting infections, and seroprevalence results during the Omicron period indicate extensive community spread of SARS-CoV-2 infection.

Technical Update No. 439: Antenatal Corticosteroids at Late Preterm Gestation.

OBJECTIVE: To update recommendations for administration of antenatal corticosteroids in the late preterm period. TARGET POPULATION: Pregnant individuals at risk of preterm birth from 340 to 366 weeks gestation. OPTIONS: Administration or non-administration of a single course of antenatal corticosteroids at 340 to 366 weeks gestation. OUTCOMES: Neonatal morbidity (respiratory distress, hypoglycemia), long-term neurodevelopment, and other long-term outcomes (growth, cardiac/metabolic, respiratory). BENEFITS, HARMS, AND COSTS: Administration of antenatal corticosteroids from 340 to 366 weeks gestation decreases the risk of neonatal respiratory distress but increases the risk of neonatal hypoglycemia. The long-term impacts of antenatal corticosteroid administration from 340 to 366 weeks gestation are uncertain. EVIDENCE: For evidence on the neonatal effects of antenatal corticosteroid administration at late preterm gestation, we summarized evidence from the 2020 Cochrane review of antenatal corticosteroids and combined this with evidence from published randomized trials identified by searching Ovid MEDLINE from January 1, 2020, to May 11, 2022. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on neurodevelopmental outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on neurodevelopmental outcomes using the following sources: (1) the 2020 Cochrane review; and (2) evidence obtained by searching Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception to January 5, 2022. We did not apply date or language restrictions. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on other long-term outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on other long-term outcomes by combining findings from the 2020 Cochrane review with evidence obtained by searching Ovid MEDLINE for observational studies related to long-term cardiometabolic, respiratory, and growth effects of antenatal corticosteroids from inception to October 22, 2021. We reviewed reference lists of included studies and relevant systematic reviews for additional references. See Appendix A for search terms and summaries. VALIDATION METHODS: The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix B (Tables B1 for definitions and B2 for interpretations of strong and conditional [weak] recommendations). INTENDED AUDIENCE: Maternity care providers, including midwives, family physicians, and obstetricians. SUMMARY STATEMENTS: RECOMMENDATIONS.

Association of SARS-CoV-2 Infection During Pregnancy With Maternal and Perinatal Outcomes.

Importance: There are limited high-quality, population-level data about the effect of SARS-CoV-2 infection on pregnancy using contemporaneous comparator cohorts. Objectives: To describe maternal and perinatal outcomes associated with SARS-CoV-2 infection in pregnancy and to assess variables associated with severe disease in the pregnant population. Design, Setting, and Participants: CANCOVID-Preg is an observational surveillance program for SARS-CoV-2-affected pregnancies in Canada. This analysis presents exploratory, population-level data from 6 Canadian provinces for the period of March 1, 2020, to October 31, 2021. A total of 6012 pregnant persons with a positive SARS-CoV-2 polymerase chain reaction test result at any time in pregnancy (primarily due to symptomatic presentation) were included and compared with 2 contemporaneous groups including age-matched female individuals with SARS-CoV-2 and unaffected pregnant persons from the pandemic time period. Exposure: SARS-CoV-2 infection during pregnancy. Incident infections in pregnancy were reported to CANCOVID-Preg by participating provinces/territories. Main Outcomes and Measures: Maternal and perinatal outcomes associated with SARS-CoV-2 infection as well as risk factors for severe disease (ie, disease requiring hospitalization, admission to an intensive care unit/critical care unit, and/or oxygen therapy). Results: Among 6012 pregnant individuals with SARS-CoV-2 in Canada (median age, 31 [IQR, 28-35] years), the greatest proportion of cases were diagnosed at 28 to 37 weeks' gestation (35.7%). Non-White individuals were disproportionately represented. Being pregnant was associated with a significantly increased risk of SARS-CoV-2-related hospitalization compared with SARS-CoV-2 cases among all women aged 20 to 49 years in the general population of Canada (7.75% vs 2.93%; relative risk, 2.65 [95% CI, 2.41-2.88]) as well as an increased risk of intensive care unit/critical care unit admission (2.01% vs 0.37%; relative risk, 5.46 [95% CI, 4.50-6.53]). Increasing age, preexisting hypertension, and greater gestational age at diagnosis were significantly associated with worse maternal outcomes. The risk of preterm birth was significantly elevated among SARS-CoV-2-affected pregnancies (11.05% vs 6.76%; relative risk, 1.63 [95% CI, 1.52-1.76]), even in cases of milder disease not requiring hospitalization, compared with unaffected pregnancies during the same time period. Conclusions and Relevance: In this exploratory surveillance study conducted in Canada from March 2020 to October 2021, SARS-CoV-2 infection during pregnancy was significantly associated with increased risk of adverse maternal outcomes and preterm birth.

Delayed cord clamping in small for gestational age preterm infants.

BACKGROUND: Infants with restricted growth for age are frequently exposed to insufficient placental circulation and are more likely to develop postnatal complications. Delayed cord clamping at birth for these infants requires further exploration. OBJECTIVE: This study aimed to compare the short-term neonatal outcomes of delayed cord clamping with that of early cord clamping in small for gestational age preterm infants and to explore whether the effects of delayed cord clamping in small for gestational age preterm infants are different from that in non-small for gestational age preterm infants. STUDY DESIGN: We conducted a national retrospective cohort study, including infants born at <33 weeks' gestation and admitted to the Canadian Neonatal Network units between January 2015 and December 2017. Small for gestational age infants (birthweight of <10th percentile for gestational age and sex) who received delayed cord clamping ≥30 seconds were compared with those who received early cord clamping. In addition, non-small for gestational age infants who received delayed cord clamping were compared with those who received early cord clamping. The main study outcomes included composite outcome of mortality or major morbidity, neonatal morbidity rate, mortality rate, peak serum bilirubin, and number of blood transfusions. Multivariable logistic and linear regression models with a generalized estimation equation approach were used to account for the clustering of infants within centers. RESULTS: Overall, 9722 infants met the inclusion criteria. Of those infants, 1027 (10.6%) were small for gestational age. The median (interquartile range) gestational age was 31 weeks (range, 28-32 weeks). After adjusting for potential confounders, delayed cord clamping in small for gestational age infants was associated with a reduction in the composite outcome of mortality or major morbidity (adjusted odds ratio, 0.60; 95% confidence interval, 0.42-0.86) compared with early cord clamping. There was no difference between the 2 groups in peak serum bilirubin. Many associated benefits of delayed cord clamping in small for gestational age infants were similar to those in non-small for gestational age infants. CONCLUSION: Delayed cord clamping in small for gestational age preterm infants was associated with decreased odds of mortality or major morbidity. Many of the benefits of delayed cord clamping in the small for gestational age preterm infants were similar to those identified in the non-small for gestational age preterm infants.

Guideline No. 401: Sonographic Cervical Length in Singleton Pregnancies: Techniques and Clinical Applications.

OBJECTIVES: • To assess the association between sonography-derived cervical length measurement and preterm birth. • To describe the various techniques to measure cervical length using sonography. • To review the natural history of the short cervix. • To review the clinical uses, predictive ability, and utility of sonography-measured short cervix. OUTCOMES: Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions. INTENDED USERS: Clinicians involved in the obstetrical management or cervical imaging of patients at increased risk of a short cervix. TARGET POPULATION: Women at increased risk of a short cervix or at risk of preterm birth. EVIDENCE: Literature published up to June 2019 was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, cervical insufficiency, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. VALUES: The evidence and this guideline were reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made and graded according to the rankings of the Canadian Task Force on Preventive Health Care (Online Appendix Table A1). BENEFITS, HARMS, COSTS: Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the sonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth. SUMMARY STATEMENTS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES): RECOMMENDATIONS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES).

A Comparison of Strategies for Managing the Umbilical Cord at Birth in Preterm Infants.

OBJECTIVE: To evaluate the rates of practice, and the associations between different cord management strategies at birth (delayed cord clamping [DCC], umbilical cord milking [UCM], and early cord clamping [ECC]) and mortality or major morbidity, rates of blood transfusion, and peak serum bilirubin in a large national cohort of very preterm infants. STUDY DESIGN: We retrospectively studied preterm infants <33 weeks of gestation admitted to the Canadian Neonatal Network between January 2015 and December 2017. Patients who received ECC (<30 seconds), UCM, or DCC (≥30 seconds) were compared. Multiple generalized linear/quantile logistic regression models were used. RESULTS: Of 12 749 admitted infants, 9729 were included; 4916 (50.5%) received ECC, 394 (4.1%) UCM, and 4419 (45.4%) DCC. After adjustment for potential confounders identified between groups in univariate analyses, the odds of mortality or major morbidity were higher in the ECC group when compared with UCM group (aOR, 1.18; 95% CI, 1.03-1.35). Mortality and intraventricular hemorrhage were associated with ECC as compared with DCC (aOR, 1.6 [95% CI, 1.22-2.1] and aOR, 1.29 [95% CI, 1.19-1.41], respectively). The odds of severe intraventricular hemorrhage were higher with UCM compared with DCC (aOR, 1.38; 95% CI, 1.05-1.81). Rates of blood transfusion were higher with ECC compared with UCM and DCC (aOR, 1.67 [95% CI, 1.31-2.14] and aOR, 1.68 [95% CI, 1.35-2.09], respectively), although peak serum bilirubin levels were not significantly different. CONCLUSIONS: Both DCC and UCM were associated with better short-term outcomes than ECC; however, the odds of severe intraventricular hemorrhage were higher with UCM compared with DCC.

The Rates of Any Breastfeeding at the Time of Postpartum Hospital Discharge for Early Term (370-386 Weeks) Versus Full Term (390-416 Weeks) Infants.

OBJECTIVE: This study sought to compare the rates of any breastfeeding between early term (370-386 weeks) and full term (390-416 weeks) infants at the time of postpartum hospital discharge. METHODS: A retrospective cohort study of women with live, singleton pregnancies who were delivered in St. John's, Newfoundland and Labrador, between April 2001 and March 2018 was completed. The primary outcome was any breastfeeding at the time of postpartum hospital discharge. Secondary analyses included a comparison of breastfeeding by week of gestational age at term and by maternal and neonatal demographics and outcomes of pregnancy. Univariate and multiple logistic regression analyses were performed. RESULTS: A total of 34 511 women were included. Early term infants were less likely to be breastfed than were full-term infants (67.9 vs. 70.4%) (adjusted odds ratio [aOR] 0.91; 95% confidence interval [CI] 0.86-0.97). Multiple logistic regression analysis also showed a significant effect of maternal age (aOR 1.07; 95% CI 1.05-1.09), partner status (aOR 1.56; 95% CI 1.20-2.03), smoking (aOR 0.32; 95% CI 0.26-0.41), prenatal education (aOR 2.43; 95% CI 1.99-2.97), pre-pregnancy body mass index (kg/m2) (aOR 0.97; 95% CI 0.96-0.98), and cesarean section (aOR 0.72; 95% CI 0.60-0.88). When compared by week of gestational age at term, the likelihood of breastfeeding significantly increased with each successive week (aOR 1.08; 95% CI 1.007-1.16). CONCLUSION: Early term delivery is an independent risk factor for not breastfeeding at the time of postpartum hospital discharge. It is important to target and support these women to increase breastfeeding rates. Additionally, these findings further validate recommendations to avoid non-medically indicated early term deliveries because of the increased risks of adverse outcomes.

Population-based cohort study of hospital delivery volume, geographic accessibility, and obstetric outcomes.

OBJECTIVE: To determine associations between geographic accessibility, delivery volume, and obstetric outcomes. METHODS: Population-based cohort study of linked hospital administrative, census, and geospatial data (2006-2009) from all Canadian jurisdictions except Quebec. Perinatal mortality and major maternal morbidity/mortality were compared across categories of road distance and hospital delivery volume. RESULTS: Among 820 761 mothers delivering 827 504 neonates, travel distance had minimal effect on perinatal mortality. Compared with mothers travelling 0-9 km, the odds of adverse maternal outcomes was decreased for women travelling modest distances (20-49 km, odds ratio, 0.80 [95% confidence interval, 0.75-0.86]), and increased thereafter (50-99 km, 0.99 [0.89-1.10]; 200-299 km, 1.44 [1.10-1.87]; >400 km, 2.22 [1.06-4.63]). Relative to high-volume hospitals (>2500 deliveries/year), adverse maternal outcomes were less likely for hospitals with 1000-2499 (0.90 [0.86-0.95]), and roughly equivalent for hospitals with 200-499 (1.34 [1.22-1.48]) and 500-999 (1.27 [1.17-1.39]) deliveries/year. Odds of perinatal mortality ranged from 1.04 (0.73-1.49; 100-199 deliveries/year) to 1.50 (1.04-2.16; 50-99 deliveries/year); the pattern did not suggest causality. CONCLUSION: Maternal outcomes worsen when travel distance is greater than 200 km, and improve when delivery volume exceeds 1000 deliveries per year.

No 374 - Évaluation systématique de la longueur cervicale.

OBJECTIF: Passer en revue les données probantes et fournir une opinion indiquant si l'évaluation systématique de la longueur cervicale pour la prévention de l'accouchement prématuré devrait être adoptée au Canada. RéSULTATS: Les issues évaluées comprennent la prévention de l'accouchement prématuré. DONNéES PROBANTES: Nous avons interrogé les bases de données Knowledge Finder, Medline et Cochrane pour en tirer les articles publiés jusqu'en avril 2018 sur la mesure de la longueur cervicale pour la prévention de l'accouchement prématuré. CRITèRES: Les données obtenues ont été examinées et évaluées par le Comité d'imagerie diagnostique de la SOGC sous la direction des auteurs principaux, et les recommandations ont été formulées selon les lignes directrices rédigées par le Groupe d'étude canadien sur les soins de santé préventifs. AVANTAGES, DéSAVANTAGES, ET COûTS: La prévention de l'accouchement prématuré sans coûts excessifs est très importante pour la santé des mères et des familles. La présente opinion de comité résume les données probantes actuelles sur l'évaluation systématique de la longueur cervicale pour prévenir l'accouchement prématuré au Canada, détermine si elle satisfait les critères de Jungner et Wilson pour un test de dépistage et formule des recommandations pour son utilisation au Canada. VALIDATION: La présente opinion a été révisée et approuvée par le comité d'imagerie diagnostique de la SOGC et la Société des obstétriciens et gynécologues du Canada (SOGC). COMMANDITAIRE: La Société des obstétriciens et gynécologues du Canada (SOGC).

No. 374-Universal Cervical Length Screening.

OBJECTIVE: To review the evidence and provide an opinion as to whether universal cervical length screening to prevent preterm birth should be adopted across Canada. OUTCOMES: Outcomes evaluated include prevention of preterm birth. EVIDENCE: Literature searches using Knowledge Finder, Medline and Cochrane databases were searched for articles published up to April 2018 on cervical length screening for prevention of preterm birth. VALUES: The evidence obtained was reviewed and evaluated by the Diagnostic Imaging Committee of the SOGC under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS: The prevention of preterm birth in a cost-effective manner is of significant importance to the health of mothers and their families. This committee opinion will summarize the current evidence for universal cervical length screening to prevent preterm birth in Canada, determine whether it meets the Junger and Wilson criteria for screening tests, and make recommendations as to its use in Canada. VALIDATION: These guidelines have been reviewed and approved by the Diagnostic Imaging Committee of the SOGC and The Society of Obstetricians and Gynaecologists of Canada (SOGC). SPONSORS: The Society of Obstetricians and Gynaecologists of Canada (SOGC).

A Common Language: What Exactly Does 34 Weeks Gestation Mean?

There are multiple conventions for gestational age notation, which lead to different interpretations of completed weeks. This variability is exemplified by the different gestational age ranges recommended for administration of antenatal corticosteroid prophylaxis. Antenatal corticosteroid prophylaxis is widely recommended for women at risk of preterm delivery up to 34 completed weeks gestation. According to the World Health Organization, 34 completed weeks refers to the time period from the first day of the last menstrual period (day zero) to 34 weeks and 6 days of gestation (i.e., to 34+6 34 weeks, or 244 days gestation). However, an alternative convention interprets 34 completed weeks as the period from the first day of the last menstrual period to 33+6 36 weeks' gestation (i.e., 237 days' gestation). These inconsistencies in gestational age notation may have led to different practice recommendations for antenatal corticosteroid prophylaxis worldwide. Agreeing on the World Health Organization notation and interpretation of completed weeks may help promote clear communication within our discipline and more precise and effective knowledge dissemination.

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.

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.

Are There Differences between Women who Choose Elective Repeat Caesarean Versus Trial of Labour in St. John's, NL?

OBJECTIVES: To compare the demographic and clinical characteristics between women who chose elective repeat Caesarean section (ERCS) versus trial of labour after Caesarean section (TOLAC) in St. John's, Newfoundland and Labrador (NL). METHODS: We conducted a retrospective case control study of women with live singleton gestations delivering at term in St. John's, NL between January 1, 2001 and December 31, 2014. Inclusion criteria were women who had a previous single lower segment Caesarean section (LSCS). TOLAC, successful TOLAC, and VBAC rates were calculated. Demographic and clinical characteristics were compared between women who chose ERCS versus TOLAC. Univariate analyses and multiple logistic regression analyses were performed, and adjusted odds ratios (aOR) and 95% CIs were calculated. RESULTS: A total of 1579 women were included, of whom 160 (10.1%) chose TOLAC, with 107 resulting in successful VBAC (67% successful TOLAC rate). The overall VBAC rate was 6.8%. Women who chose ERCS compared with those who chose TOLAC were more likely to be obese (aOR 3.20, 95% CI 1.85-5.54, P < 0.001), less likely to have had GA at delivery greater than 40 weeks (aOR 0.13, 95% CI 0.08-0.21, P < 0.001), less likely to have had a previous vaginal delivery (aOR 0.40, 95% CI 0.20-0.80, P < 0.001), and less likely to have had the previous CS for breech presentation (aOR 0.51, 95% CI 0.33-0.80, P = 0.003). CONCLUSIONS: The overall TOLAC and VBAC rates in St. John's are low when compared with reported national rates. The successful TOLAC rate is within the expected range reported in the literature. Differences exist between women who chose ERCS compared with TOLAC.