Planned delivery route and outcomes of cephalic singletons born spontaneously at 24-31 weeks' gestation: The EPIPAGE-2 cohort study

Cesarean delivery is associated with lower neonatal mortality among breech pregnancies: a systematic review and meta-analysis of preterm deliveries ≤32 weeks of gestation

OBJECTIVE

To investigate the association between actual and planned modes of delivery, neonatal mortality, and short-term outcomes among preterm pregnancies ≤32 weeks of gestation.

DATA SOURCES

A systematic literature search was conducted in 3 main databases (PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to November 16, 2022. The protocol was registered in advance in the International Prospective Register of Systematic Reviews (CRD42022377870).

STUDY ELIGIBILITY CRITERIA

Eligible studies examined pregnancies ≤32nd gestational week. All infants received active care, and the outcomes were reported separately by different modes of delivery. Singleton and twin pregnancies at vertex and breech presentations were included. Studies that included pregnancies complicated with preeclampsia and abruptio placentae were excluded. Primary outcomes were neonatal mortality and intraventricular hemorrhage.

STUDY APPRAISAL AND SYNTHESIS METHODS

Articles were selected by title, abstract, and full text, and disagreements were resolved by consensus. Random effects model-based odds ratios with corresponding 95% confidence intervals were calculated for dichotomous outcomes. Risk Of Bias In Non-randomized Studies - of Interventions-I was used to assess the risk of bias.

RESULTS

A total of 19 observational studies were included involving a total of 16,042 preterm infants in this systematic review and meta-analysis. Actual cesarean delivery improves survival (odds ratio, 0.62; 95% confidence interval, 0.42-0.9) and decreases the incidence of intraventricular hemorrhage (odds ratio, 0.70; confidence interval, 0.57-0.85) compared to vaginal delivery. Planned cesarean delivery does not improve the survival of very and extremely preterm infants compared to vaginal delivery (odds ratio, 0.87; 95% confidence interval, 0.53-1.44). Subset analysis found significantly lower odds of death for singleton breech preterm deliveries born by both planned (odds ratio, 0.56; 95% confidence interval, 0.32-0.98) and actual (odds ratio, 0.34; 95% confidence interval, 0.13-0.88) cesarean delivery.

CONCLUSION

Cesarean delivery should be the mode of delivery for preterm ≤32 weeks of gestation breech births due to the higher mortality in preterm infants born via vaginal delivery.

Timing of antenatal corticosteroids and survival without neurologic disabilities at 5½ years in children born before 35 weeks of gestation

BACKGROUND

The efficacy of antenatal corticosteroids for neonatal preterm complications wanes beyond 7 days after treatment. The neurodevelopmental effects of longer treatment-to-birth intervals have not been adequately evaluated.

OBJECTIVE

This study aimed to assess the impact of antenatal corticosteroid timing on survival without moderate or severe neurologic disabilities at 5½ years.

STUDY DESIGN

This was a secondary analysis of the EPIPAGE-2 study, a national population-based cohort (France) that recruited neonates in 2011 and followed them up at 5½ years (results first reported in 2021). Participants were children born alive between 24+0 and 34+6 weeks, with a complete corticosteroid course, delivery >48 hours after the first injection, and neither limitation of care decided before birth nor severe congenital malformation. The study included 2613 children, 2427 of whom were alive at 5½ years; 71.9% (1739/2427) had a neurologic assessment at this age; 1537 had a clinical examination (complete for 1532), and 202 were assessed with a postal questionnaire. Exposure was defined as the interval between the first injection of the last antenatal corticosteroid course and delivery in days, studied in 2 categories (days 3-7 and after day 7), in 4 categories (days 3-7, 8-14, 15-21, and after day 21), and continuously in days. The main outcome was survival at 5½ years without moderate/severe neurologic disabilities, defined as moderate/severe cerebral palsy, or unilateral or bilateral blindness or deafness, or Full-Scale Intelligence Quotient 2 standard deviations below the mean. A multivariate analysis with a generalized estimated equation logistic regression model assessed the statistical association between the main outcomes and the interval from the first corticosteroid injection of the last course to birth. Multivariate analyses were adjusted for potential confounders, defined with a directed acyclic graph: gestational age in days, number of corticosteroid courses, multiple pregnancy, and cause of prematurity in 5 categories. Because neurologic follow-up was complete in only 63.2% of cases (1532/2427), the analyses used imputed data.

RESULTS

Among 2613 children, 186 died between birth and 5½ years. Overall survival was 96.6% (95% confidence interval, 95.9-97.0), and survival without moderate or severe neurologic disabilities was 86.0% (95% confidence interval, 84.7-87.0). Survival without moderate or severe neurologic disabilities was lower after day 7 (85.0%) than during the interval from day 3 to day 7 (87.0%) (adjusted odds ratio, 0.70; 95% confidence interval, 0.54-0.89).

CONCLUSION

The association of a >7-day interval between antenatal corticosteroid administration and birth with a lower rate of survival without moderate or severe neurologic disabilities among children aged 5½ years emphasizes the importance of better targeting women at risk of preterm delivery to optimize the timing and thus benefits of treatment.

Effect of mode of delivery on perinatal outcome in severe preterm birth: systematic review and meta-analysis

OBJECTIVE

To review the evidence on the effect of mode of delivery on perinatal outcome of fetuses born before 32 weeks' gestation.

METHODS

MEDLINE, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), the ClinicalTrials.gov registry and gray literature sources were searched, starting from the year 2000 to reflect contemporary practice in perinatal care. Non-randomized or randomized studies that included singleton fetuses without chromosomal abnormality or major congenital defect delivered vaginally or via Cesarean section were eligible for inclusion in the analysis. Primary outcomes were neonatal death, defined as death in the first 28 days of age, and survival to discharge. Secondary outcomes were other adverse perinatal events. The ROBINS-I tool was used to assess the risk of bias. The overall quality of evidence for the outcomes was assessed according to GRADE. Summary odds ratios (ORs) with 95% CIs were calculated, and random-effects models were used for data synthesis. Subgroup analysis was performed for delivery before 28 weeks, delivery between 28 and 32 weeks and according to fetal presentation at delivery.

RESULTS

A total of 27 retrospective studies (22 887 neonates) were included in the systematic review and meta-analysis, all of which reported on singleton pregnancies. Among cases born before 28 weeks, vaginal delivery significantly increased the risk of neonatal death of fetuses with any type of presentation (n = 1496) (OR 1.87 (95% CI, 1.05-3.35); I2  = 65%, very low quality of evidence) and of fetuses with breech presentation (n = 733) (OR 3.55 (95% CI, 2.42-5.21); I2  = 21%, moderate quality of evidence). The odds of survival to discharge were significantly decreased among fetuses with breech presentation delivered before 28 weeks (n = 646) (OR 0.36 (95% CI, 0.24-0.54); I2  = 21%, low quality of evidence). Among breech fetuses born between 28 and 32 weeks, vaginal delivery increased the odds of perinatal death (intrapartum and neonatal) (n = 1581) (OR 3.06 (95% CI, 1.47-6.35); I2  = 0%, high quality of evidence). In non-cephalic fetuses born between 24 and 32 weeks, vaginal delivery decreased the odds of survival to discharge (n = 1030) (OR 0.28 (95% CI, 0.19-0.40); I2  = 0%, moderate quality of evidence). No significant effect on mortality of mode of delivery was observed in cephalic fetuses at any gestational age.

CONCLUSIONS

This systematic review and meta-analysis suggests that vaginal delivery in severe preterm birth is associated with an increased risk of neonatal and perinatal death in breech fetuses, while no significant association was observed for cephalic fetuses. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Neurodevelopmental Outcome at Corrected Age of 2 Years among Children Born Preterm with Operative Vaginal Delivery: A Population-Based Study (LIFT Cohort)

The aim of the study was to determine whether operative vaginal delivery (OVD) was associated with non-optimal neurocognitive development at the corrected age of 2 years for preterm singletons using the Loire Infant Follow-up Team (LIFT) longitudinal cohort, a French regional perinatal network and prospective, population-based cohort of preterm infants. For this study, we included women with cephalic singletons and planned vaginal delivery from 24 to 34 weeks' gestation between 2006 and 2016. The main exposure was the mode of delivery (spontaneous vaginal delivery (SVD), OVD, and cesarean delivery (CS) during labor). The primary outcome was non-optimal neurodevelopmental outcome at the corrected age of 2 years assessed by a physical examination, a neuropsychological test, and/or a parental questionnaire. Secondary outcomes were survival at discharge and survival at discharge without morbidity. We used the multivariate logistic regression and propensity score methods to compare outcomes associated with OVD. The study included 1934 infants born preterm: 1384 (71.6%) with SVD, 87 (4.5%) with OVD, and 463 (23.9%) with CS. Neonates with SVD, OVD, and CS did not differ in survival (97.0%, 97.7%, and 97.8%, respectively; p = 0.79) or in survival without morbidity (82.8%, 86.2%, and 82.7%, respectively; p = 0.71). In survived infants, 1578 (81.6%) were evaluated at age two: 279 (17.7%) were considered to have a non-optimal neurodevelopmental outcome (18.3% after SVD, 18.0% after OVD, and 15.9% after CS; p = 0.57). Propensity score analysis showed that OVD was not associated with non-optimal neurocognitive development at age two, with an adjusted odds ratio (aOR) of 0.86 and a 95% confidence interval (95% CI) of 0.47-1.69, compared with SVD; and an aOR of 0.76 and a 95% CI of 0.31-1.8, compared with CS. Operative vaginal delivery was not associated with non-optimal neurocognitive development at 2 years of corrected age for preterm singletons.

Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/025, September 2022) - Part 2 with Recommendations on the Tertiary Prevention of Preterm Birth and on the Management of Preterm Premature Rupture of Membranes

Aim The revision of this guideline was coordinated by the German Society for Gynecology and Obstetrics (DGGG), the Austrian Society for Gynecology and Obstetrics (OEGGG) and the Swiss Society for Gynecology and Obstetrics (SGGG). The aim of the guideline is to improve the prediction, prevention and management of preterm birth based on evidence from the current literature, the experience of members of the guidelines commission, and the viewpoint of self-help organizations. Methods The members of the contributing professional societies and organizations developed recommendations and statements based on international literature. The recommendations and statements were presented and adopted using a formal process (structured consensus conferences with neutral moderation, written Delphi vote). Recommendations Part 2 of this short version of the guideline presents statements and recommendations on the tertiary prevention of preterm birth and the management of preterm premature rupture of membranes.

A Narrative Review of Methods for Causal Inference and Associated Educational Resources

BACKGROUND AND OBJECTIVES

Root cause analysis involves evaluation of causal relationships between exposures (or interventions) and adverse outcomes, such as identification of direct (eg, medication orders missed) and root causes (eg, clinician's fatigue and workload) of adverse rare events. To assess causality requires either randomization or sophisticated methods applied to carefully designed observational studies. In most cases, randomized trials are not feasible in the context of root cause analysis. Using observational data for causal inference, however, presents many challenges in both the design and analysis stages. Methods for observational causal inference often fall outside the toolbox of even well-trained statisticians, thus necessitating workforce training.

METHODS

This article synthesizes the key concepts and statistical perspectives for causal inference, and describes available educational resources, with a focus on observational clinical data. The target audience for this review is clinical researchers with training in fundamental statistics or epidemiology, and statisticians collaborating with those researchers.

RESULTS

The available literature includes a number of textbooks and thousands of review articles. However, using this literature for independent study or clinical training programs is extremely challenging for numerous reasons. First, the published articles often assume an advanced technical background with different notations and terminology. Second, they may be written from any number of perspectives across statistics, epidemiology, computer science, or philosophy. Third, the methods are rapidly expanding and thus difficult to capture within traditional publications. Fourth, even the most fundamental aspects of causal inference (eg, framing the causal question as a target trial) often receive little or no coverage. This review presents an overview of (1) key concepts and frameworks for causal inference and (2) online documents that are publicly available for better assisting researchers to gain the necessary perspectives for functioning effectively within a multidisciplinary team.

CONCLUSION

A familiarity with causal inference methods can help risk managers empirically verify, from observed events, the true causes of adverse sentinel events.