The role of antenatal corticosteroids in twin pregnancies complicated by preterm birth

Antenatal corticosteroids and newborn respiratory outcomes in twins: A regression discontinuity study

OBJECTIVE

To estimate the effect of antenatal corticosteroids on newborn respiratory morbidity in twins.

DESIGN

Regression discontinuity applied to population-based birth registry data.

SETTING

British Columbia, Canada, 2008-2018.

POPULATION

Twin pregnancies admitted for birth between 31+0 and 36+6 weeks of gestation.

METHODS

During our study period, Canadian clinical practice guidelines recommended antenatal corticosteroid administration for imminent preterm birth up to 33+6 weeks. We used a logistic model to compare the predicted risks of our outcomes among pregnancies admitted for birth immediately before this clinical cut-point (higher probability of exposure to antenatal corticosteroids) versus immediately after it (lower probability).

MAIN OUTCOME MEASURES

Our primary outcome was a composite of newborn respiratory distress or in-hospital death. Our secondary outcome was a composite of newborn respiratory intervention or in-hospital death.

RESULTS

Among 2524 pregnancies (5035 liveborn twins), 47% of admissions before 34+0 weeks of gestation were exposed to antenatal corticosteroids but only 4.2% of admissions after this cut-point were exposed. The risk of newborn respiratory distress or in-hospital mortality increased abruptly at 34+0 weeks, corresponding to a protective effect of treatment (risk ratio [RR] 0.69, 95% CI 0.53-0.90; risk difference [RD] -12 cases per 100 births, 95% CI -20 to -4.1). There was no clear evidence for or against an effect on newborn respiratory intervention or in-hospital death (RR 0.89, 95% CI 0.70-1.13; RD -4.2 per 100, 95% CI -13 to +4.2).

CONCLUSIONS

Our findings provide evidence for the effectiveness of antenatal corticosteroids in preventing adverse newborn respiratory outcomes in twins.

Antenatal corticosteroid administration is associated with lower risk of severe ROP in preterm twin infants

INTRODUCTION

Robust evidence revealed the impact of antenatal corticosteroid (ACS) administration on lower mortality and short-term neonatal outcomes in singleton preterm infants. We aimed to investigate the impact of ACS therapy on morbidity and mortality in preterm twin infants.

METHODS

We conducted this retrospective single-center study from to the records of twin babies of 24-30 weeks of gestation admitted to the neonatal intensive care unit. The study population was grouped based on the exposure to ACS 1-7 days before birth as received or not. Groups were compared regarding in-hospital mortality and neonatal outcomes.

RESULTS

Data from 160 twin infants were analyzed. Of those, 102 (64 %) were administered ACS. The median (IQR) gestational age and birth weight of the whole cohort were 28 (27-29) weeks and 1060 (900-1240) g, respectively. ACS administration was associated with a significant decline in respiratory distress syndrome (RDS), requirement ≥2 doses of surfactant, severe intraventricular hemorrhage (IVH), early-onset sepsis (EOS), and retinopathy of prematurity (ROP) requiring treatment (p < 0.05). Logistic regression analysis revealed that gestational age (OR 0.29 95 % CI 0.14-0.62; p = 0.001), ACS administration (OR 0.14 95 % CI 0.03-0.85; p = 0.032), and time to achieve full enteral feeding (OR 1.16 95 % CI 1.03-1.31; p = 0.019) were independently associated with the risk of severe ROP.

CONCLUSION

The reduction in the risk of severe ROP besides RDS, severe IVH, and EOS among preterm twins who received ACS was remarkable in our study similar to the trials conducted in preterm singletons. However, large-scale prospective observational studies are required to reveal the efficacy of ACS in preterm twins.

European guidelines on perinatal care: corticosteroids for women at risk of preterm birth

of recommendationsCorticosteroids should be administered to women at a gestational age between 24⁺⁰ and 33⁺⁶weeks, when preterm birth is anticipated in the next seven days, as these have been consistently shown to reduce neonatal mortality and morbidity. (Strong-quality evidence; strong recommendation). In selected cases, extension of this period up to 34⁺⁶weeks may be considered (Expert opinion). Optimal benefits are found in infants delivered within 7 days of corticosteroid administration. Even a single-dose administration should be given to women with imminent preterm birth, as this is likely to improve neurodevelopmental outcome (Moderate-quality evidence; conditional recommendation).Either betamethasone (12 mg administered intramuscularly twice, 24-hours apart) or dexamethasone (6 mg administered intramuscularly in four doses, 12-hours apart, or 12 mg administered intramuscularly twice, 24-hours apart), may be used (Moderate-quality evidence; Strong recommendation). Administration of two "all" doses is named a "course of corticosteroids".Administration between 22⁺⁰ and 23⁺⁶weeks should be considered when preterm birth is anticipated in the next seven days and active newborn life-support is indicated, taking into account parental wishes. Clear survival benefit has been observed in these cases, but the impact on short-term neurological and respiratory function, as well as long-term neurodevelopmental outcome is still unclear (Low/moderate-quality evidence; Weak recommendation).Administration between 34 + 0 and 34 + 6 weeks should only be offered to a few selected cases (Expert opinion). Administration between 35⁺⁰ and 36⁺⁶weeks should be restricted to prospective randomized trials. Current evidence suggests that although corticosteroids reduce the incidence of transient tachypnea of the newborn, they do not affect the incidence of respiratory distress syndrome, and they increase neonatal hypoglycemia. Long-term safety data are lacking (Moderate quality evidence; Conditional recommendation).Administration in pregnancies beyond 37⁺⁰weeks is not indicated, even for scheduled cesarean delivery, as current evidence does not suggest benefit and the long-term effects remain unknown (Low-quality evidence; Conditional recommendation).Administration should be given in twin pregnancies, with the same indication and doses as for singletons. However, existing evidence suggests that it should be reserved for pregnancies at high-risk of delivering within a 7-day interval (Low-quality evidence; Conditional recommendation). Maternal diabetes mellitus is not a contraindication to the use of antenatal corticosteroids (Moderate quality evidence; Strong recommendation).A single repeat course of corticosteroids can be considered in pregnancies at less than 34⁺⁰weeks gestation, if the previous course was completed more than seven days earlier, and there is a renewed risk of imminent delivery (Low-quality evidence; Conditional recommendation).

Antenatal prediction models for outcomes of extremely and very preterm infants based on machine learning

PURPOSE

Predicting individual risks for adverse outcomes in preterm infants is necessary for perinatal management and antenatal counseling for their parents. To evaluate whether a machine learning approach can improve the prediction of severe infant outcomes beyond the performance of conventional logistic models, and to identify maternal and fetal factors that largely contribute to these outcomes.

METHODS

A population-based retrospective study was performed using clinical data of 31,157 infants born at < 32 weeks of gestation and weighing ≤ 1500 g, registered in the Neonatal Research Network of Japan between 2006 and 2015. We developed a conventional logistic model and 6 types of machine learning models based on 12 maternal and fetal factors. Discriminative ability was evaluated using the area under the receiver operating characteristic curves (AUROCs), and the importance of each factor in terms of its contribution to outcomes was evaluated using the SHAP (SHapley Additive exPlanations) value.

RESULTS

The AUROCs of the most discriminative machine learning models were better than those of the conventional models for all outcomes. The AUROCs for in-hospital death and short-term adverse outcomes in the gradient boosting decision tree were significantly higher than those in the conventional model (p = 0.015 and p = 0.002, respectively). The SHAP value analyses showed that gestational age, birth weight, and antenatal corticosteroid treatment were the three most important factors associated with severe infant outcomes.

CONCLUSION

Machine learning models improve the prediction of severe infant outcomes. Moreover, the machine learning approach provides insight into the potential risk factors for severe infant outcomes.

Post Antenatal Late Preterm Steroids trial: interrupted time series analysis of respiratory outcomes in twin and pregestational diabetes

BACKGROUND

The Antenatal Late Preterm Steroids trial found that corticosteroid administration decreased respiratory complications by 20% among late preterm singleton deliveries. After the Antenatal Late Preterm Steroids trial, corticosteroid administration increased by 76% among twin pregnancies and 113% among singleton pregnancies complicated by pregestational diabetes mellitus compared with expected rates based on the pre-Antenatal Late Preterm Steroids trial trend. However, the effect of corticosteroids on twin pregnancies and pregnancies complicated by pregestational diabetes mellitus is not well studied, as the Antenatal Late Preterm Steroids trial excluded twin pregnancies and pregnancies complicated by pregestational diabetes mellitus.

OBJECTIVE

This study aimed to examine the change in the incidence rate of immediate assisted ventilation use and ventilation use for more than 6 hours among 2 populations after the dissemination of the Antenatal Late Preterm Steroids trial at the population level.

STUDY DESIGN

This study was a retrospective analysis of publicly available US birth certificate data. The study period was from August 1, 2014, to April 30, 2018. The dissemination period of the Antenatal Late Preterm Steroids trial was from February 2016 to October 2016. Population-based interrupted time series analyses were performed for 2 target populations: (1) twin pregnancies not complicated by pregestational diabetes mellitus and (2) singleton pregnancies complicated by pregestational diabetes mellitus. For both target populations, analyses were limited to individuals who delivered nonanomalous live neonates between 34 0/7 and 36 6/7 weeks of gestation (vaginal or cesarean delivery). As a sensitivity analysis, a total of 23 placebo tests were conducted before (5 tests) and after (18 tests) the dissemination period.

RESULTS

For the analysis of late preterm twin deliveries, 191,374 individuals without pregestational diabetes mellitus were identified. For the analysis of late preterm singleton pregnancy with pregestational diabetes mellitus, 21,395 individuals were identified. After the dissemination period, the incidence rate of immediate assisted ventilation use for late preterm twin deliveries was significantly lower than the expected value based on the pre-Antenatal Late Preterm Steroids trial trend (11.6% observed vs 13.0% expected; adjusted incidence rate ratio, 0.87; 95% confidence interval, 0.78-0.97). The incidence rate of ventilation use for more than 6 hours among late preterm twin deliveries did not change significantly after the dissemination of the Antenatal Late Preterm Steroids trial. A significant increase in the incidence rate of immediate assisted ventilation use and ventilation use for more than 6 hours was found among singleton pregnancies with pregestational diabetes mellitus. However, the results of placebo tests suggested that the increase in incidence was not necessarily due to the dissemination period of the Antenatal Late Preterm Steroids trial.

CONCLUSION

The dissemination of the Antenatal Late Preterm Steroids trial was associated with decreased incidence of immediate assisted ventilation use, but no change in ventilation use for more than 6 hours, among late preterm twin deliveries in the United States. In contrast, the incidence of neonatal respiratory outcomes among singleton deliveries with pregestational diabetes mellitus did not decrease after the dissemination of the Antenatal Late Preterm Steroids trial.

The role of antenatal corticosteroids in twin pregnancy

Twin pregnancy was associated with significantly higher rates of adverse neonatal and perinatal outcomes. One of the underlying causes is that twins are prone to preterm birth. Antenatal corticosteroids are widely used for reducing the incidence of neonatal respiratory distress syndrome initially and other neonatal mortality and morbidities subsequently. As it is widely used as a prophylactic treatment for potential premature births, there remain controversies of issues relating to twin gestations, including window for opportunity, timing of use, repeat course, optimal administration-to-delivery intervals, dosage, and type of corticosteroid. Thus, we present a thorough review of antenatal corticosteroids usage in twin gestation, emphasizing the aforementioned issues and attempting to offer direction for future investigation and clinical practice.

Effects of antenatal corticosteroids on neonatal outcomes in twin and singleton pregnancies: a Korean national cohort study

OBJECTIVE

To investigate whether effects of antenatal corticosteroids on neonatal outcomes in preterm infants with very low birth weight were different by plurality.

DESIGN

Nationwide prospective cohort study.

PATIENTS

Twins and singletons with very low birth weight (<1500 g) who were born between 23+0 and 33+6 weeks of gestation and registered in the Korean Neonatal Network from January 2014 to December 2019.

MAIN OUTCOME MEASURES

Morbidity and mortality before discharge from neonatal intensive care unit.

RESULTS

Among a total of 9531 preterm infants with very low birth weight, there were 2364 (24.8%) twins and 7167 (75.2%) singletons. While 83.9% of singletons were exposed to at least one dose of antenatal corticosteroids, so were 87.9% of twins.Interaction analysis demonstrated that there was no significant difference in the effect of antenatal corticosteroids on morbidities or mortality between twins and singletons in either gestational age group (23-28 weeks or 29-33 weeks).Antenatal corticosteroids significantly decreased the risk of surfactant use (adjusted relative risk (aRR): 0.972 (95% CI: 0.961 to 0.984)), high-grade intraventricular haemorrhage (aRR: 0.621 (95% CI: 0.487 to 0.794)), periventricular leucomalacia (aRR: 0.728 (95% CI: 0.556 to 0.954)) and mortality (aRR: 0.758 (95% CI: 0.679 to 0.846)) in the gestational age group of 23-28 weeks. In the gestational age group of 29-33 weeks, antenatal corticosteroids significantly decreased the risk of surfactant use (aRR: 0.914 (95% CI: 0.862 to 0.970)) and mortality (aRR: 0.409 (95% CI: 0.269 to 0.624)) but increased the risk of sepsis (aRR: 1.416 (95% CI: 1.018 to 1.969)).

CONCLUSION

This study demonstrates that effect of antenatal corticosteroids on neonatal outcomes of preterm infants with very low birth weight does not differ significantly by plurality (twin or singleton pregnancy).

Birth order and morbidity and mortality to hospital discharge among inborn very low-birthweight, very preterm twin infants admitted to neonatal intensive care: a retrospective cohort study

OBJECTIVE

To know the association of birth order with the risk of morbidity and mortality in very low-birthweight (VLBW) twin infants less than 32 weeks' gestational age (GA).

DESIGN

Retrospective cohort study.

SETTING

Infants admitted to the collaborating centres of the Spanish SEN1500 neonatal network.

PATIENTS

Liveborn VLBW twin infants, with GA from 23⁺⁰ weeks to 31⁺⁶ weeks, without congenital anomalies, admitted from 2011 to 2020. Outborn patients were excluded.

MAIN OUTCOME MEASURES

Respiratory distress syndrome (RDS), patent ductus arteriosus, bronchopulmonary dysplasia (BPD), necrotising enterocolitis, major brain damage (MBD), late-onset neonatal sepsis, severe retinopathy of prematurity, survival and survival without morbidity. Crude and adjusted incidence rate ratios were calculated.

RESULTS

Among 2111 twin pairs included, the second twin had higher risk (adjusted risk ratio (aRR) of RDS (aRR 1.08, 95% CI 1.03 to 1.12) and need for surfactant (aRR1.10, 95% CI 1.05 to 1.16). No other significant differences were found, neither in survival (aRR 1.01, 95% CI 0.99 to 1.03) nor in survival without BPD (aRR 1.02, 95% CI 0.99 to 1.05), survival without MBD (aRR 1.02, 95% CI 0.99 to 1.06) nor in survival without major morbidity (aRR 0.97, 95% CI 0.92 to 1.03). However, second twins born by caesarean section (C-section) after a vaginally delivered first twin had less overall survival and survival without MBD.

CONCLUSION

In modern perinatology, second twins are still more unstable immediately after birth and require more resuscitation. After admission to the neonatal intensive care unit, they are at increased risk of RDS, but not other conditions, except for second twins delivered by C-section after a first twin delivered vaginally, who have decreased overall survival and survival without major brain injury.

Premature monochorionic monoamniotic twins have lower lung compliance at birth than matched dichorionic diamniotic twins

BACKGROUND: Premature infants are born with immature lungs that demonstrate abnormal pulmonary function with differences in passive respiratory system compliance and resistance, and functional residual capacity. To our knowledge, no studies have evaluated differences in neonatal pulmonary function based on the type of twin gestation, or chorionicity. Given the effect of chorionicity on outcomes, we aimed to study the effect of twin type, monochorionic monoamniotic (MCMA) vs dichorionic diamniotic (DCDA), on neonatal early pulmonary function tests. METHODS: In this prospective cohort study, 5 sets of DCDA twins were matched to 5 sets of MCMA twins on gestational age at delivery, latency from antenatal corticosteroid exposure, birthweight, race and gender. Mean values were compared for passive respiratory system compliance and resistance, functional residual capacity, and tidal volume. RESULTS: MCMA infants had a significantly lower compliance (0.64 vs 1.25 mL/cm H2O /kg; p = 0.0001) and significantly higher resistance (0.130 vs 0.087 cm H2O /mL/sec; p = 0.0003) than DCDA infants. Functional residual capacity was lower for MCMA than DCDA infants (17.5 vs 23.4 mL/kg; p = 0.17). Further, 80% of MCMA infants required intubation for surfactant administration compared to 20% of DCDA infants, indicating the clinical significance of these objective measures. CONCLUSIONS: Due to the matched case-control design, causality cannot be established. However, we speculate that these differences in lung function may derive from differential exposure to preterm labor and endogenous maternal corticosteroid exposure. Further study is necessary to establish the true causal relationship.

Guideline No. 428: Management of Dichorionic Twin Pregnancies

OBJECTIVE

To review evidence-based recommendations for the management of dichorionic twin pregnancies.

TARGET POPULATION

Pregnant women with a dichorionic twin pregnancy.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline may improve the management of twin pregnancies and reduce neonatal and maternal morbidity and mortality.

EVIDENCE

Published literature was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary (e.g., twin, preterm birth). Results were restricted to systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date limits, but results were limited to English- or French-language materials.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. 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 A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for women with twin pregnancies.

SUMMARY STATEMENTS

RECOMMENDATIONS.

The Effect of Incompletely Administered Antenatal Corticosteroids on Neonatal Pulmonary Outcomes in Late Preterm Infants

Purpose: Recent obstetric guidelines recommend the administration of antenatal corticosteroids in pregnant women at risk of delivering infants at a gestational age between 34 and 36 weeks. We examined the effect of incompletely administered antenatal corticosteroids on the neonatal pulmonary outcomes in late preterm infants.Methods: Late preterm infants (34⁺⁰ to 36⁺⁶ weeks gestational age) born at the Seoul National University Bundang Hospital from January 2019 to June 2020 were retrospectively enrolled. We excluded multiple births except twins, those with major congenital anomalies, deaths, or transfers to other hospitals. An incomplete course of antenatal corticosteroids was defined as one in which the first or the second dose of betamethasone was administered within 24 hours before delivery. The rates of neonatal pulmonary morbidities were compared between late preterm infants given incomplete courses antenatal corticosteroids and their peers who not given antenatal corticosteroids; these morbidities included respiratory distress syndrome and transient tachypnea of the newborn, assisted ventilation including invasive mechanical ventilation, nasal continuous positive airway pressure and high-flow nasal cannula, and admission to neonatal intensive care unit.Results: Logistic regression models were constructed while adjusting for factors which were significant in bivariate models. After adjusting for baseline maternal and neonatal characteristics, we found no significant differences in the rates of neonatal pulmonary morbidities, assisted ventilation, or admission to the neonatal intensive care unit between late preterm infants who received incomplete antenatal corticosteroid therapy and their peers who were not given any antenatal corticosteroids.Conclusion: Incompletely administered antenatal corticosteroids did not significantly alter the neonatal pulmonary outcomes in late preterm infants.

Association between antenatal corticosteroids use and perinatal mortality among preterm singletons and twins in Mwanza, Tanzania: an observational study

OBJECTIVES

To examine the association between antenatal corticosteroids (ACS) use and perinatal mortality in singletons and twins delivered before 35 weeks of gestation.

DESIGN

Secondary analysis of data from an observational prospective chart review study that investigated if exposure to ACS was associated with lower rates of perinatal mortality in preterm infants.

SETTING

This study was conducted in four hospitals located in Mwanza region, Tanzania.

PARTICIPANTS

The study population included all preterm singletons and twins delivered at these hospitals between 24 weeks 0 days and 34 weeks 6 days of gestation from July 2019 to February 2020.

OUTCOME MEASURES

The primary outcome was perinatal mortality; the secondary outcome was respiratory distress syndrome (RDS).

RESULTS

The study included 844 singletons and 210 twin infants. Three hundred and fourteen singletons (37.2%) and 52 twins (24.8%) were exposed to at least one dose of ACS. Adjusted multivariate analyses revealed that among singletons' exposure to ACS was significantly associated with a lower likelihood of perinatal mortality, adjusted relative risk (aRR) 0.30 (95% CI 0.22 to 0.40) and RDS, aRR 0.92 (95% CI 0.87 to 0.97). In twin infants, exposure to ACS was associated with a reduced risk of RDS only, aRR 0.87 (95% CI 0.78 to 0.98).

CONCLUSION

The use of ACS between 24 weeks 0 days and 34 weeks 6 days of gestation in both singletons and twins in low-resource settings is associated with positive infant outcomes. No adverse effects were noted. Further research that examines the benefits of ACS for twin infants is needed.

Beyond Fetal Immunity: A Systematic Review and Meta-Analysis of the Association Between Antenatal Corticosteroids and Retinopathy of Prematurity

Background: Retinopathy of prematurity (ROP) is a major cause of childhood blindness. Antenatal corticosteroids (ACS) exposure is known to ameliorate the risk of and mortality of neonatal morbidities. However, the effect of ACS on ROP development is currently unknown. We conducted a meta-analysis with up-to-date evidence to assess the association between ACS exposure and the development of ROP in at-risk preterm infants.

Methods: PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library were systematically searched from inception to May 2021, supplemented with manual search from reference lists. Studies with a control group reporting ROP rate in ACS-exposed infants were included. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated utilizing a random-effects model. The Newcastle-Ottawa Scale was used for assessment of risk of bias in the included studies. Meta-regressions were performed to explore the predictive role of confounders for between-study variance.

Results: A total of 63 studies, involving 196,264 infants, were included. Meta-analysis showed ACS exposure was not associated with ROP occurrence (uOR 0.92, 95% CI 0.80–1.07; aOR 0.87, 95% CI 0.7–1.08). Results from extremely immature subgroups revealed significant reduced risks of ROP occurrence in ACS-exposed infants. ACS exposure was associated with significantly lower odds of ROP progression in adjusted analysis (aOR 0.48, 95% CI 0.26–0.89) instead of unadjusted analysis (uOR 0.86, 95% CI 0.68–1.08). Meta-regression showed birth weight and patent ductus arteriosus of the cohort were associated with ROP occurrence, sample size and study design strongly associated with ROP progression in ACS-exposed infants.

Conclusion: ACS treatment may decrease, but not prevent, the severity of ROP. Findings from severe ROP should be interpreted with caution owing to limited studies and the possibility of false-positive results. Considering the particular benefits in extremely immature infants, we recommend routine usage of ACS in mothers with threatened delivery to this particular birth cohort to prevent ROP occurrence. Future studies adjusting for major confounders are warranted to mitigate risk of bias in such observational evidence.

Society for Maternal-Fetal Medicine Consult Series #58: Use of antenatal corticosteroids for individuals at risk for late preterm delivery: Replaces SMFM Statement #4, Implementation of the use of antenatal corticosteroids in the late preterm birth period in women at risk for preterm delivery, August 2016

The administration of antenatal corticosteroids has been widely adopted as the standard of care in the management of pregnancies at risk for preterm delivery before 37 weeks of gestation, with the primary goal of reducing neonatal morbidity. However, the long-term risks associated with antenatal corticosteroid use remain uncertain. The purpose of this Consult is to review the current literature on the benefits and risks of antenatal corticosteroid use in the late preterm period and to provide recommendations based on the available evidence. The recommendations by the Society for Maternal-Fetal Medicine are as follows: (1) we recommend offering a single course of antenatal corticosteroids (2 doses of 12 mg of intramuscular betamethasone 24 hours apart) to patients who meet the inclusion criteria of the Antenatal Late Preterm Steroids trial, ie, those with a singleton pregnancy between 34 0/7 and 36 6/7 weeks of gestation who are at high risk of preterm birth within the next 7 days and before 37 weeks of gestation (GRADE 1A); (2) we suggest consideration for the use of antenatal corticosteroids in select populations not included in the original Antenatal Late Preterm Steroids trial, such as patients with multiple gestations reduced to a singleton gestation on or after 14 0/7 weeks of gestation, patients with fetal anomalies, or those who are expected to deliver in <12 hours (GRADE 2C); (3) we recommend against the use of antenatal corticosteroids for fetal lung maturity in pregnant patients with a low likelihood of delivery before 37 weeks of gestation (GRADE 1B); (4) we recommend against the use of late preterm corticosteroids in pregnant patients with pregestational diabetes mellitus, given the risk of worsening neonatal hypoglycemia (GRADE 1C); (5) we recommend that patients at risk for late preterm delivery be thoroughly counseled regarding the potential risks and benefits of antenatal corticosteroid administration and be advised that the long-term risks remain uncertain (GRADE 1C).

Association of antenatal corticosteroids with morbidity and mortality among preterm multiple gestations: meta-analysis of observational studies

OBJECTIVE

This meta-analysis aimed to assess the efficacy of antenatal corticosteroids (ACS) on morbidity and mortality among preterm multiple pregnancies.

METHODS

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies investigating the outcomes among preterm multiple gestations following to ACS, from their inception to 1 November 2020. Two authors independently performed the study selection, risk of bias assessment and data extraction. The primary outcomes were respiratory distress syndrome (RDS) and mortality and secondary outcomes included intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), necrotising enterocolitis, retinopathy of prematurity and bronchopulmonary dysplasia. Pooled ORs were obtained using random effects models. Subgroup analyses were performed to explain heterogeneity by ACS completeness, administration-to-delivery intervals (≤7 days) and single or multicentre.

RESULTS

A total of 16 observational studies with 36 973 newborns were included in the meta-analysis. ACS treatment was associated with a reduction in RDS (OR 0.66; 95% CI 0.54 to 0.82; I2=91.4%; p<0.001), mortality (OR 0.64; 95% CI 0.50 to 0.81; I2=85.9%; p<0.001), IVH (OR 0.67; 95% CI 0.54 to 0.83; I2=77.4%; p<0.001) and PVL (OR 0.65; 95% CI 0.47 to 0.92; I2=75.5%; p<0.001). Subgroup analyses showed ACS completeness, administration-to-delivery interval and multicentre study affected these associations.

DISCUSSION

ACS may be beneficial for reducing the risks of RDS, mortality, IVH and PVL among preterm multiple gestations. The efficacy of ACS could be affected by ACS completeness and administration-to-delivery. More robust evidence on the efficacy of ACS treatment among multiple gestations is warranted.

Rescue antenatal corticosteroids and neonatal outcomes in twin gestation

OBJECTIVE

Although repeated antenatal corticosteroids (ACS) courses are not recommended, a single rescue ACS course has been shown to decrease neonatal morbidity among preterm singletons. However, little is known regarding the effects of rescue ACS course in twin pregnancies.

METHODS

A retrospective cohort study conducted during 2015-2017 at a tertiary-care center including all twins delivered between 24-34 weeks of gestation who received at least one course of ACS.

RESULTS

Overall, 162 (70.4%) twins were exposed to a single ACS course and 68 (29.6%) to an additional rescue ACS course. Rescue ACS course was associated with lower rates of respiratory distress syndrome (7.4% vs. 19.1%, p = .03), surfactant use (7.4% vs 18.5%, p = .04) and bronchopulmonary dysplasia (0 vs 8.6%, p = .01) as compared to a single ACS course. In the rescue ACS group, compared to the single ACS group, the rates of composite respiratory adverse outcome (10.3% vs 22.2%, OR [95% CI]: 0.40 (0.17-0.95), p = .04) and any adverse neonatal outcome (13.2% vs 26.5%, OR [95% CI]: 0.42 (0.19-0.92), p = .04) were significantly lower. Hospital stay was also shorter among neonates born to mothers receiving a rescue ACS course (median 23 vs. 30 days, p = .01). No differences were noted in neonatal birthweight, head circumference and the rate of neonatal hypoglycemia.

CONCLUSION

Rescue ACS course was associated with improved respiratory and neonatal outcomes in twin gestations. Further studies are warranted to confirm our findings and better delineate the optimal regimen of rescue ACS in this setting.

Evaluation of the effectiveness of antenatal corticoid in preterm twin and single pregnancies: a multicenter cohort study

BACKGROUND

The effects of antenatal corticosteroids (ANSs) on twins are not well established.

OBJECTIVE

To determine the impact of ANS use according to the number of fetuses.

METHODS

Retrospective cohort study of newborns between 23 and 33 weeks of gestational age, birth weight from 400 to 1499 g, without malformations, delivered at 20 public university hospitals from 2010 to 2014.Exposed group: Received ANS (any time, any dose) and no exposed group: no received ANS. Analysis of birth conditions and clinical outcomes. Association of variables, relative risks, and 95% confidence intervals estimated from the adjustment of log-binomial regression models.

RESULTS

About 7165 premature infants were analyzed: 5167 singleton, 937 twins, and 104 triplets. Characteristics of gestations with one, two, or three fetuses not receiving ANS were similar. Reduced hemodynamic instability in single and twins gestations in the first 72 h were observed (Adj R² Twins = 0.78; 95% CI = 0.69-0.86) (Adj R² Singles = 0.79; 95% CI = 0.62-0.99). Reduced peri-intraventricular hemorrhage (Adj R² Twins = 0.54; 95% CI = 0.36-0.78) (Adj R² singles = 0.54; 95% CI = 0.36-0.78); and early sepsis reduction on single and triplex gestations (Adj R² triplex = 0.51; 95% CI = 0.27-0.94) (Adj single R² = 0.51; 95% CI = 0.27-0.94) were observed.

CONCLUSIONS

This study demonstrates ANS produces an important protective factor for severe intraventricular hemorrhage and hemodynamic instability in single and multiple pregnancies. ANS had a protective effect on death and birth conditions improvement just in single gestations. Regarding respiratory aspects was not observed the protective effect in the single or multiple gestations.

Controversies in the management of twin pregnancy

Despite many advances in antenatal care, twin pregnancies still experience more adverse outcomes, in particular perinatal morbidity and mortality. They also pose a multitude of challenges and controversies, as outlined in this Review. Moreover, they are less likely to be included in clinical trials. Many issues on classification and management remain under debate. Efforts at standardizing diagnostic criteria, monitoring protocols, management and outcome reporting are likely to reduce their perinatal risks. The top 10 most important research uncertainties related to multiple pregnancies have been identified by both clinicians and patients. More robust research in the form of randomized trials and large well-conducted prospective cohort studies is needed to address these controversies. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Evidence for the Management of Bronchopulmonary Dysplasia in Very Preterm Infants

BACKGROUND

Very preterm birth often results in the development of bronchopulmonary dysplasia (BPD) with an inverse correlation of gestational age and birthweight. This very preterm population is especially exposed to interventions, which affect the development of BPD.

OBJECTIVE

The goal of our review is to summarize the evidence on these daily procedures and provide evidence-based recommendations for the management of BPD.

METHODS

We conducted a systematic literature research using MEDLINE/PubMed on antenatal corticosteroids, surfactant-replacement therapy, caffeine, ventilation strategies, postnatal corticosteroids, inhaled nitric oxide, inhaled bronchodilators, macrolides, patent ductus arteriosus, fluid management, vitamin A, treatment of pulmonary hypertension and stem cell therapy.

RESULTS

Evidence provided by meta-analyses, systematic reviews, randomized controlled trials (RCTs) and large observational studies are summarized as a narrative review.

DISCUSSION

There is strong evidence for the use of antenatal corticosteroids, surfactant-replacement therapy, especially in combination with noninvasive ventilation strategies, caffeine and lung-protective ventilation strategies. A more differentiated approach has to be applied to corticosteroid treatment, the management of patent ductus arteriosus (PDA), fluid-intake and vitamin A supplementation, as well as the treatment of BPD-associated pulmonary hypertension. There is no evidence for the routine use of inhaled bronchodilators and prophylactic inhaled nitric oxide. Stem cell therapy is promising, but should be used in RCTs only.

Advances in Management for Preterm Fetuses at Risk of Delivery

Preterm birth accounts for only 11% of live births but contributes to up to 75% of neonatal mortality and more than half of long-term morbidity. Targeted interventions to reduce the most common causes of perinatal morbidity and mortality include intrapartum group B Streptococcus prophylaxis, magnesium sulfate for fetal neuroprotection, antenatal corticosteroids for fetal lung maturity, latency antibiotics for preterm premature rupture of membranes, and tocolysis to allow corticosteroid administration and transfer to a tertiary care center. This article reviews the evidence for interventions to improve outcomes for fetuses at risk for preterm delivery at different gestational ages.

Two-stage nomogram models in mid-gestation for predicting the risk of spontaneous preterm birth in twin pregnancy

PURPOSE

This study aimed to develop two-stage nomogram models to predict individual risk of preterm birth at < 34 weeks of gestation in twin pregnancies by incorporating clinical characteristics at mid-gestation.

METHODS

We used a case-control study design of women with twin pregnancies followed up in a tertiary medical centre from January 2018 to March 2019. Maternal demographic characteristics and transvaginal cervical length data were extracted. The nomogram models were constructed with independent variables determined by multivariate logistic regression analyses. The risk score was calculated based on the nomogram models.

RESULTS

In total, 65 twin preterm birth cases (< 34 weeks) and 244 controls met the inclusion criteria. Based on univariate and multivariate logistic regression analyses, we built two-stage nomogram prediction models with satisfactory discrimination and calibration when applied to the validation sets (first-stage [22-24 weeks] prediction model, C-index: 0.805 and 0.870, respectively; second-stage [26-28 weeks] prediction model, C-index: 0.847 and 0.908, respectively). Restricted cubic splines graphically showed the risk of preterm birth among individuals with increased risk scores. Moreover, the decision curve analysis indicated that both prediction models show positive clinical benefit.

CONCLUSION

We developed and validated two-stage nomogram models at mid-gestation to predict the individual probability of preterm birth at < 34 weeks in twin pregnancy.

Antenatal corticosteroids administration on mortality and morbidity in premature twins born at 25∼34 gestational weeks: A retrospective multicenter study

OBJECTIVE

To evaluate the effects of antenatal corticosteroids (ACS) administration on mortality and major neonatal complications in early life of preterm twins.

STUDY DESIGN

This study retrospectively enrolled 1 662 twins delivered at 25∼34⁺⁶gestational weeks in China from January 2013 to December 2014. They were divided into ACS group and no-ACS group according to weather their mothers received ACS or not. Moreover, they were subgrouped as 25∼27⁺⁶ and 28∼34⁺⁶gestational week groups. Multivariable logistic regression was used to analyze the effects of ACS on the incidence of mortality and major morbidities.

RESULTS

A total of 910 neonates (54.8 %) received one or more doses of ACS, and 752 neonates (45.2 %) did not receive any ACS. No significant difference in infant mortality was observed between the ACS and no-ACS groups (P = 0.321). The ACS group had decreased incidence of respiratory distress syndrome (RDS) and mild RDS compared with the no-ACS group (both P < 0.05). There were no significant differences in the incidence of bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, retinopathy of prematurity, patent ductus arteriosus, sepsis and severe RDS between the two groups (all P > 0.05). The subgroup analysis showed that the incidence of RDS was lower in the ACS group than in the no-ACS group (P = 0.036) at 28∼34⁺⁶weeks. However, the incidence of mild ROP was higher in the ACS group than that in the no-ACS group (P = 0.047) at 25∼27⁺⁶ weeks. Multivariable logistic regression analysis demonstrated a decreasing risk of RDS (aOR = 0.661, 95 %CI:0.506-0.863, P = 0.002) after adjusting the gestational week, birth weight, small for gestational age, delivery mode, 5 min Apgar score, and maternal perinatal complications.

CONCLUSION

In twin preterm infants, ACS administration is associated with a reduced risk of RDS. However, our data suggest that it may not have a beneficial effect on mortality and other short-term morbidities.

Does antenatal steroids treatment in twin pregnancies prior to late preterm birth reduce neonatal morbidity? Evidence from a retrospective cohort study

PURPOSE

To evaluate whether antenatal corticosteroids (ACS) administration during the late-preterm (LPT) period in twin pregnancies is associated with decreased rate of neonatal morbidity.

METHODS

A retrospective cohort study including a total of 290 women with twin pregnancies resulting in live births of 580 neonates who delivered during LPT period between 2016 and 2018 at a tertiary medical center. Patients were allocated into two groups according to ACS exposure. Obstetric and neonatal outcomes were compared between the groups. Primary outcome was neonatal composite respiratory morbidity, defined as the occurrence of at least one of the followings: RDS, TTN, O2 requirement, CPAP use or mechanical ventilation.

RESULTS

Patients exposed to ACS were older and more commonly complicated by gestational diabetes compared to the non-exposed group. Moreover, women exposed to ACS delivered earlier (35.6 vs. 36.3 weeks, P < 0.001) and more frequently by cesarean section (76.4% vs. 54.1%, P = 0.002) compared to the non-exposed group. The rate of composite respiratory morbidity did not differ between the groups. Nevertheless, neonates exposed to ACS had higher rates of neonatal intensive care unit (NICU) admission and hypoglycemia compared to neonates without prior ACS exposure (27.8% vs. 11.7%, P = 0.001; 49.3% vs. 27.1%, P < 0.001, respectively). Multivariable logistic regression revealed that gestational age at delivery was the sole independent risk factor for NICU admission, whereas late-preterm ACS exposure was the only risk factor for hypoglycemia.

CONCLUSION

LPT-ACS administration in twin pregnancies complicated by LPT birth in our study did not reduce neonatal respiratory morbidity but was associated with higher rates of hypoglycaemia.

Antenatal corticosteroid administration for foetal lung maturation

Antenatal corticosteroids are an essential component in the management of women at risk for preterm labour. They promote lung maturation and reduce the risk of other preterm neonatal complications. This narrative review discusses the contentious issues and controversies around the optimal use of antenatal corticosteroids and their consequences for both the mother and the neonate. The most recent evidence base is presented.

Controversies in antenatal corticosteroid treatment

Antenatal corticosteroids are now established as one of the cornerstones of therapy in the prevention of neonatal morbidity and mortality prior to preterm birth. Although this practice is widely accepted, a significant number of controversies exist. This review explores the knowledge gaps regarding the use of antenatal corticosteroids in the preterm, late preterm and term populations. Furthermore, the role of antenatal corticosteroids in special populations, such as diabetes, multiple pregnancies and periviable gestations, where high-quality data from randomized controlled trials are lacking, is also considered.

Cumulative effect of evidence-based practices on outcomes of preterm infants born at <29 weeks' gestational age

BACKGROUND

Extremely preterm infants born at <29 weeks' gestational age are at high risk of death or severe neurological injury. Several individual evidence-based practices have been associated with neuroprotection.

OBJECTIVE

The objective of the study was to investigate the cumulative effect of 4 evidence-based practices and their association with death and/or severe neurological injury among infants born at <29 weeks' gestational age.

STUDY DESIGN

Observational study of infants born at 23⁰-28⁶ weeks gestational age admitted to neonatal intensive care units participating in the Canadian Neonatal Network from 2015 through 2017. We evaluated 4 practices: antenatal corticosteroids, antenatal MgSO₄ for neuroprotection, deferred cord clamping ≥30 seconds, and normothermia on admission. The effect of exposure to 1, 2, 3, and all 4 evidence-based practices compared with none on death and/or severe neurological injury was assessed using multivariable logistic regression models adjusted for patient characteristics.

RESULTS

Rate of death and/or severe neurological injury was 20% (873 of 4297) and varied based on exposure to evidence-based practices: none, 34% (54 of 157); 1, 27% (171 of 626); 2, 20% (295 of 1448); 3, 18% (263 of 1448); and all 4, 14% (90 of 618). Significantly lower odds of death and/or severe neurological injury were observed with exposure to antenatal corticosteroids (adjusted odds ratio, 0.52, 95% confidence interval, 0.40-0.69) and deferred cord clamping (adjusted odds ratio, 0.81, 95% confidence interval, 0.68-0.96) but not MgSO₄ (adjusted odds ratio, 0.88, 95% confidence interval, 0.72-1.08) or normothermia (adjusted odds ratio, 0.96, 95% confidence interval, 0.79-1.16). Infants exposed to ≥2 evidence-based practices had significantly lower odds of death and/or severe neurological injury than those exposed to no evidence-based practices (adjusted odds ratio, 0.61, 95% confidence interval, 0.43-0.88).

CONCLUSION

Among infants born at <29 weeks' gestational age, exposure to at least 2 of the evidence-based practices assessed was associated with decreased odds of death and/or severe neurological injury.

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.

Respiratory morbidity in late preterm twin infants

PURPOSE

Antenatal corticosteroids have been shown to decrease neonatal respiratory morbidity in singleton pregnancies when given during the late-preterm period (34^0/7-36^6/7 weeks). Whether these findings also apply to late-preterm twins, who account for approximately one-third of infants born at 34^0/7-35^6/7 weeks, is currently unclear. The answer to this question depends, in part, on whether the risk of respiratory morbidity among late-preterm twin infants is similar to that observed in late-preterm singletons. We aimed to assess the rate of respiratory morbidity among late-preterm twin infants using a secondary analysis of prospectively collected data from a large international multicenter trial, and to compare that rate with previous studies that used the same definition of respiratory morbidity.

STUDY DESIGN

This was a secondary analysis of the twin birth study. In the current study, we limited the analysis to women who gave birth during the late preterm period. The primary outcomes were the same primary composite respiratory morbidity variables that were used in the randomized controlled trial of Gyamfi-Bannerman et al., on the administration of betamethasone during the late preterm period in singletons (ALPS trial). The risk of respiratory morbidity among late preterm twins was stratified by gestational week at birth.

RESULTS

A total of 1163 women who gave birth to 2324 late preterm twin infants met the inclusion criteria. The rates of respiratory morbidity and severe respiratory morbidity were 16.5% and 8.9%, respectively. The risk of respiratory morbidity was highly dependent on gestational week at birth, being more than fourfold for infants born at 34^0/7-34^6/7 weeks (aOR 4.30, 95%-CI 3.01-6.14) and more than twofold for infants born at 35^0/7-35^6/7 weeks (aOR 2.12, 95%-CI 1.51-2.98) compared with infants born at 36^0/7-36^6/7 weeks. The rate of respiratory morbidity and the theoretical number of women needed to be treated with betamethasone to prevent a single case of respiratory morbidity in the current study were similar to those reported in the APLS trial (16.5% vs. 14.4%, p = 0.103, and NNT 31 vs. 34, respectively).

CONCLUSIONS

The risk-benefit ratio of betamethasone with regard to neonatal respiratory morbidity in women with twins at risk of late-preterm birth is expected to be similar to that observed in singletons.

Effects of antenatal corticosteroids in twin neonates with late preterm birth (ACTWIN [Antenatal Corticosteroids in TWIN late preterm neonates] trial): study protocol for a randomized controlled trial

BACKGROUND

Antenatal corticosteroids have been proven to prevent adverse outcomes including respiratory morbidities in preterm neonates before 34 weeks of gestation. Recently, it has been suggested that antenatal corticosteroids may also be effective in singleton late preterm pregnancies, and guidelines recommend the use of corticosteroids in singleton pregnant women who are at risk for late preterm birth. On the contrary, there is a paucity of information regarding the effectiveness of corticosteroids in twin neonates with late preterm birth. This study aims to determine the effectiveness of antenatal corticosteroids in late preterm twin neonates.

METHODS

In this multicentre randomized controlled trial, women who are at risk for late preterm birth will be enrolled at 34 0/7 to 36 5/7 weeks of gestation. The participants will be randomly assigned to receive antenatal corticosteroids (betamethasone 12 mg, 3 mL intramuscularly [IM]) or placebo (normal saline 3 mL IM). The perinatal outcomes will be compared between the two groups of cases. The primary outcome is severe respiratory complications (the use of continuous positive airway pressure or high-flow nasal cannula for at least 12 h, supplemental oxygen administration with a fraction of oxygen 0.3 or more for at least 24 h, mechanical ventilation, or extracorporeal membranes oxygenation) or perinatal death within the first 72 h of delivery. The secondary outcomes are neonatal mortality and/or other neonatal morbidities.

DISCUSSION

This study will be the first randomized controlled trial that evaluates the effectiveness of antenatal corticosteroids in late preterm twin neonates.

TRIAL REGISTRATION

NCT03547791 (ClinicalTrials.gov), first submitted date: March 29, 2018, first posted date: June 6, 2018 (retrospectively registered).

Neonatal outcomes of antenatal corticosteroids in preterm multiple pregnancies compared to singletons

BACKGROUND

Antenatal corticosteroids (ACS) during preterm labour reduce neonatal mortality and morbidity. Evidence on preterm multiple pregnancies is limited and contradictory.

OBJECTIVE

Compare the effect of ACS on very low birth weight infant's (VLBW) mortality and morbidity among singleton and multiple pregnancies.

STUDY DESIGN

Retrospective cohort study, employing prospectively collected data, of infants 23 to 34 weeks' gestation and 500 to 1500 g born at the Neocosur Neonatal Network centers during 2007-2016. Neonatal outcomes were compared among singleton and multiple pregnancies exposed to at least one dose of ACS to those not exposed using logistic regression analyses controlled for birthweight, gestational age, sex, small for gestational age (SGA) and mode of delivery.

RESULTS

A total of 13,864 infants were studied; 2948 multiple (21.3%) and 10,904 singleton pregnancies (78.7%). Overall, 11,218 (81.4%) received at least one dose of ACS with a significant reduction in the risk of death, RDS and grade III or IV IVH compared to those not exposed. Both singleton and multiple pregnancies exposed to ACS showed similar reduced risk of death (aRR 0.41 [95% CI, 0.36-0.47] vs. aRR 0.46 [95% CI, 0.34-0.64]). However, ACS were not associated with reduced odds of RDS (aRR 0.89 [95% CI, 0.66-1.23]) or grade III or IV IVH (aRR 0.99 [95% CI, 0.67-1.48]) in multiple pregnancies.

CONCLUSION

The benefit of administration of at least one dose of ACS in VLBW multiple and singleton pregnancies is comparable in terms of death. However, ACS showed no relevant impact in short-term morbidity in multiple pregnancies.

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 Corticosteroids: Who Should We Be Treating?

Antenatal corticosteroids remain one of the crucial interventions in those at risk for imminent preterm birth. Therapeutic benefits include reducing major complications of prematurity such as respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis, as well as an overall decrease in neonatal deaths. Optimal reductions in neonatal morbidity and mortality require a thoughtful review of the timing of administration. In addition, a thorough understanding is required of which patients maximally benefit from this intervention in the management and counseling of those at risk for preterm birth.

Accuracy of fetal fibronectin for the prediction of preterm birth in symptomatic twin pregnancies: a pilot study

Our goal was to evaluate the performance of fetal fibronectin (fFN) test alone or combined with cervical length (CL), to predict spontaneous preterm birth (PTB) in symptomatic twin pregnancies. We carry out a short pilot study including all uncomplicated diamniotic twin pregnancies with symptoms of preterm labor (PTL) and intact membranes at 24-33 weeks + 6 days of gestation. Studied outcome were spontaneous delivery within 7 and 14 days of testing and spontaneous PTB at <34 and <37 weeks of gestation. Among 40 women, fFN test was positive in 3 of them (7.5%). Regardless of the outcome studied CL did not significantly predict PTB. Performance of fFN was sensitivity (66.7%), specificity (97.2%), positive predictive value (66.7%), negative predictive value (97.2%), positive likelihood ratio (LR) (24.0), and negative LR (0.3) to predict spontaneous PTB within 7 days (p = 0.01). Thus, 66.1% of patients with a positive fFN test would deliver within 7 days versus 2.4% if negative testing; starting with a pre-test probability of 7.5%. Combining CL and fFN did not enable to increase enough positive LR or decrease significantly negative LR. In conclusion, fFN test alone might have a better ability to detect spontaneous delivery within 7 days among symptomatic twin pregnancies.

The Canadian Preterm Birth Network: a study protocol for improving outcomes for preterm infants and their families

BACKGROUND

Preterm birth (birth before 37 wk of gestation) occurs in about 8% of pregnancies in Canada and is associated with high mortality and morbidity rates that substantially affect infants, their families and the health care system. Our overall goal is to create a transdisciplinary platform, the Canadian Preterm Birth Network (CPTBN), where investigators, stakeholders and families will work together to improve childhood outcomes of preterm neonates.

METHODS

Our national cohort will include 24 maternal-fetal/obstetrical units, 31 neonatal intensive care units and 26 neonatal follow-up programs across Canada with planned linkages to provincial health information systems. Three broad clusters of projects will be undertaken. Cluster 1 will focus on quality-improvement efforts that use the Evidence-based Practice for Improving Quality method to evaluate information from the CPTBN database and review the current literature, then identify potentially better health care practices and implement identified strategies. Cluster 2 will assess the impact of current practices and practice changes in maternal, perinatal and neonatal care on maternal, neonatal and neurodevelopmental outcomes. Cluster 3 will evaluate the effect of preterm birth on babies, their families and the health care system by integrating CPTBN data, parent feedback, and national and provincial database information in order to identify areas where more parental support is needed, and also generate robust estimates of resource use, cost and cost-effectiveness around preterm neonatal care.

INTERPRETATION

These collaborative efforts will create a flexible, transdisciplinary, evaluable and informative research and quality-improvement platform that supports programs, projects and partnerships focused on improving outcomes of preterm neonates.

Efficacy of Antenatal Corticosteroid Treatment on Neurodevelopmental Outcome according to Head Circumference at Birth

BACKGROUND

There are concerns about the efficacy of antenatal corticosteroid treatment (ACT) in the growth-restricted fetus.

OBJECTIVE

To evaluate the effect of ACT on neurodevelopmental outcome at 2 years of corrected age according to the z score of birth head circumference (ZS HC) in a large prospective cohort of preterm infants.

METHODS

This study was conducted as a population-based, prospective, multicenter study, including 4,965 infants born between 24 and 33 weeks' gestation and whose status regarding ACT and the measurement of head circumference at birth were available. They were evaluated at 2 years of corrected age to assess neurological outcome. Three approaches were considered to estimate the effect of ACT on neurodevelopment: (i) logistic regression with adjustment on propensity score, (ii) weighted logistic regression using the inverse probability of treatment weighting method, and (iii) 1:1 matching of gestational age, ZS HC, and propensity score between treated and nontreated infants.

RESULTS

ACT was documented in 60% of infants. Three groups of infants were considered according to their ZS HC: between -3 and -1 standard deviation (SD), -1 and +1 SD, and +1 and +3 SD, respectively. ACT was associated with a significant improvement of neurodevelopmental outcome only for infants with an ZS HC of between +1 and +3 SD (adjusted OR 1.72; 95% CI 1.06-2.79). Moreover, ORs estimated in the -3 to -1 and +1 to +3 categories were significantly different.

CONCLUSION

We found beneficial effects of ACT on neurodevelopmental outcomes at 2 years of corrected age only in preterm infants with a ZS HC >1 SD.

Efficacy of antenatal corticosteroids in preterm twins: the EPIPAGE-2 cohort study

OBJECTIVES

To investigate the efficacy of antenatal corticosteroid (ACS) therapy on short-term neonatal outcomes in preterm twins, and further document the influence of the ACS-to-delivery interval.

DESIGN

EPIPAGE-2 is a nationwide observational multicentre prospective cohort study of neonates born between 22 and 34 completed weeks of gestation.

SETTING

All French maternity units, except in a single administrative region, between March and December 2011.

POPULATION

A total of 750 twin neonates born between 24 and 31 weeks of gestation.

METHODS

Exposure to ACSs was examined in four groups: single complete course, with an ACS administration-to-delivery interval of ≤7 days; single complete course, with an ACS-to-delivery interval of >7 days; repeated courses; or no ACS treatment.

MAIN OUTCOME MEASURES

Neonatal outcomes analysed were severe bronchopulmonary dysplasia, periventricular leukomalacia or intraventricular haemorrhage grade III/IV, in-hospital mortality, and a composite indicator of severe outcomes.

RESULTS

Compared with no ACSs, in multivariable analysis, a single course of ACSs with an administration-to-delivery interval of ≤7 days was significantly associated with a reduced rate of periventricular leukomalacia or intraventricular haemorrhage grade III/IV (aOR 0.2; CI 95% 0.1-0.5), in-hospital mortality (0.3; 0.1-0.6), and the composite indicator (0.1; 0.1-0.3), whereas a single course of ACDs with an administration-to-delivery interval of >7 days did not significantly reduce the frequency of in-hospital mortality (0.7; 0.3-1.8). No significant differences in terms of benefit or risk were found when comparing repeated courses with a single complete course.

CONCLUSION

In preterm twins, a single complete course of antenatal corticosteroids was associated with an improvement of severe neurological outcome, whereas reduced in-hospital mortality was seen only when the ACS-to-delivery interval was ≤7 days.

TWEETABLE ABSTRACT

A single complete course of antenatal steroids reduced severe neurological morbidity in preterm twins (24-31 weeks).

Morbidity and mortality of very low birth weight multiples compared with singletons

BACKGROUND

Previous studies comparing the neonatal outcome of very low birth weight (VLBW) multiples and singletons have suggested a worse outcome for multiples at gestational ages on the limits of viability.

OBJECTIVES

The objective of this study is to determine the neonatal mortality and morbidity of VLBW multiples compared to singletons.

METHODS

This is a retrospective study including all infants registered in the Spanish network for infants under 1500 g (SEN1500), over a 12-year period (from 2002 to 2013). Mortality and major morbidities were compared between singletons and multiples.

RESULTS

About 32,770 infants were included: 21,123 singletons (64.5%) and 11,647 multiples (35.5%), with a mean gestational age of 29.5 weeks (22-38), and mean birth weight of 1115 g (340-1500). When adjusted by other perinatal factors, multiple pregnancy has a significantly higher risk of mortality than singleton pregnancy (odds ratio (OR) 1.15; IC 95% 1.05-1.26, p = .002), but not a higher risk of major morbidity or composite adverse outcome. In the subgroup of infants born before 26 weeks, multiples showed a higher risk of mortality (63.9% versus 51%, OR 1.7; 95% CI 1.47-1.96) and a higher risk of composite adverse outcome (88.9% versus 81.5%, OR 1.82, 95% CI 1.28-2.24).

CONCLUSIONS

In preterm infants born with less than 1500 g, multiple pregnancy is a prognostic factor that can slightly increase mortality. Extremely preterm infants born before 26 weeks have a greater risk of mortality and major morbidity if they come from a multiple pregnancy.

Do serial measurements of cervical length improve the prediction of preterm birth in asymptomatic women with twin gestations?

BACKGROUND

Cervical length at midtrimester is a powerful predictor of preterm birth in twin gestations. However, given the fact that, in some cases, cervical shortening may become evident only later during the second trimester, it seems reasonable that serial monitoring of cervical length may improve the detection of preterm birth in women with twins. However, data in support of such a practice are limited and conflicting. The contradictory results may be related to the fact that in most of these studies, the analysis of the predictive value of serial measurements of cervical length was limited to data derived from only two sequential measurements of cervical length, while data on the predictive value of multiple (>2) measurements are scarce.

OBJECTIVE

We sought to determine whether serial measurements of cervical length can improve the prediction of preterm birth in asymptomatic women with twin gestations compared with a single measurement of cervical length at midgestation.

STUDY DESIGN

This was a retrospective cohort study of women with twin pregnancies followed up in a tertiary medical center from 2012 through 2014. All participants underwent routine measurement of cervical length at midgestation and every 2-3 weeks thereafter until 28-32 weeks. For each patient, cervical length was determined at the following time periods: 18+0 to 21+6 weeks (period 1, routine exam), 22+0 to 24+6 weeks (period 2), 25+0 to 27+6 weeks (period 3), and 28+0 to 32+0 weeks (period 4). Measurements of cervical length at periods 2-4 were analyzed in the form of either absolute length (in millimeters) or percent shortening relative to cervical length at period 1. The performance of a stepwise algorithm that incorporated serial measurements of cervical length for the prediction of preterm birth was compared to that achieved with a single measurement of cervical length at period 1.

RESULTS

Overall, 441 women with twin pregnancies who were eligible for the study underwent a total of 2374 cervical length measurements. The association of a short cervix (<10th percentile) with preterm birth at <32 weeks persisted in each of the 4 periods of gestation [odds ratio (95% confidence interval): 7.2 (3.1-16.5), 15.3 (6.4-36.7), 10.3 (4.4-24.3), and 23.1(8.3-64.1), respectively]. Compared with a single measurement of cervical length at midgestation (period 1), a stepwise algorithm integrating serial cervical length measurements from all 4 successive gestational age periods resulted in a significant increase in the area under the receiver operating characteristic curve (0.917 vs 0.613, P < .001). Similarly, when a target false-positive rate of 5% was used, the same stepwise algorithm was associated with a higher detection rate (69% vs 28%, P < .001), higher positive likelihood ratio (14.54 vs 5.12), and lower negative likelihood ratio (0.32 vs 0.76) for preterm birth at <32 weeks compared with a single measurement of cervical length at period 1.

CONCLUSION

Integration of serial measurements of cervical length using a stepwise algorithm in asymptomatic women with twin gestations can improve the detection of women at risk of preterm birth. Prospective studies are needed to validate these findings, and to investigate whether improved risk assessment performance is sufficient to offset the additional costs associated with serial cervical length measurements.