Design and conduct of a large obstetric or neonatal randomized controlled trial

To guide future practice, perinatal trials should be much larger, simpler and less fragile with close to 100% ascertainment of mortality and other key outcomes

The Australian Placental Transfusion Study (APTS) randomised 1,634 fetuses to delayed (≥60 s) versus immediate (≤10 s) clamping of the umbilical cord. Systematic reviews with meta-analyses, including this and similar trials, show that delaying clamping in preterm infants reduces mortality and need for blood transfusions. Amongst 1,531 infants in APTS followed up at two years, aiming to delay clamping for 60 s or more reduced the relative risk of the primary composite outcome of death or disability by 17% (p = 0.01). However, this result is fragile because nominal statistical significance (p < 0.05) would be abolished by only 2 patients switching from a non-event to an event, and the primary composite outcome was missing in 112 patients (7%). To achieve more robust evidence, any future trials should emulate the large, simple trials co-ordinated from Oxford which reliably identified moderate, incremental improvements in mortality in tens of thousands of participants, with <1% missing data. Those who fund, regulate, and conduct trials that aim to change practice should repay the trust of those who consent to participate by doing everything possible to minimise missing data for key outcomes.

Facing the Ethical Challenges: Consumer Involvement in COVID-19 Pandemic Research

Consumer involvement in clinical research is an essential component of a comprehensive response during emergent health challenges. During the COVID-19 pandemic, the moderation of research policies and regulation to facilitate research may raise ethical issues. Meaningful, diverse consumer involvement can help to identify practical approaches to prioritize, design, and conduct rapidly developed clinical research amid current events. Consumer involvement might also elucidate the acceptability of flexible ethics review approaches that aim to protect participants whilst being sensitive to the challenging context in which research is taking place. This article describes the main ethical challenges arising from pandemic research and how involving consumers and the community could enable resolution of such issues.

Current Recommendations and Practice of Oxygen Therapy in Preterm Infants

This narrative review identified 23 publications in 2011 to 2019 discussing randomized trials of oxygen saturation targets of 85% to 89% versus 91% to 95% in infants below 28 weeks' gestation. Of 18 commentaries or consensus statements, 17 recommended saturation targets above 89%. Five systematic reviews reported that the 85% to 89% target increased mortality but not the composite of death or disability. The evidence for increased mortality was assessed as of "high", "moderate," or "low," quality, reflecting substantial differences in interpreting the GRADE guidelines. Systematic reviews and guidelines without biostatisticians or epidemiologists as co-authors should be considered potentially problematic.

Medication Use and Pain Management in Pregnancy: A Critical Review

BACKGROUND

Pain during pregnancy is common, and its management is complex. Certain analgesics may increase the risk for adverse fetal and pregnancy outcomes, while poorly managed pain can result in adverse maternal outcomes such as depression and hypertension. Guidelines to assist clinicians in assessing risks and benefits of exposure to analgesics for the mother and unborn infant are lacking, necessitating evidence-based recommendations for managing pain in pregnancy.

METHODS

A comprehensive literature search was conducted to assess pregnancy safety data for pharmacological and nonpharmacological pain management methods. Relevant clinical trials and observational studies were identified using multiple medical databases, and included studies were evaluated for quality and possible biases.

RESULTS

Paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) are appropriate for mild to moderate pain, but NSAIDs should be avoided in the third trimester due to established risks. Short courses of weaker opioids are generally safe in pregnancy, although neonatal abstinence syndrome must be monitored following third trimester exposure. Limited safety data for pregabalin and gabapentin indicate that these are unlikely to be major teratogens, and tricyclic antidepressants and serotonin-norepinephrine reuptake inhibitors have limited but overall reassuring safety data. Many of the included studies were limited by methodological issues.

CONCLUSIONS

Findings from this review can guide clinicians in their decision to prescribe analgesics for pregnant women. Treatment should be tailored to the lowest therapeutic dose and shortest possible duration, and management should involve a discussion of risks and benefits and monitoring for response. Further research is required to better understand the safety profile of various analgesics in pregnancy.

Preterm Infant Outcomes after Randomization to Initial Resuscitation with FiO2 0.21 or 1.0

OBJECTIVE

To determine rates of death or neurodevelopmental impairment (NDI) at 2 years corrected age (primary outcome) in children <32 weeks' gestation randomized to initial resuscitation with a fraction of inspired oxygen (FiO₂) value of 0.21 or 1.0.

STUDY DESIGN

Blinded assessments were conducted at 2-3 years corrected age with the Bayley Scales of Infant and Toddler Development, Third Edition or the Ages and Stages Questionnaire by intention to treat.

RESULTS

Of the 290 children enrolled, 40 could not be contacted and 10 failed to attend appointments. Among the 240 children for whom outcomes at age 2 years were available, 1 child had a lethal congenital anomaly, 1 child had consent for follow-up withdrawn, and 23 children died. The primary outcome, which was available in 238 (82%) of those randomized, occurred in 47 of the 117 (40%) children assigned to initial FiO₂ 0.21 and in 38 of the 121 (31%) assigned to initial FiO₂ 1.0 (OR, 1.47; 95% CI, 0.86-2.5; P = .16). No difference in NDI was found in 215 survivors randomized to FiO₂ 0.21 vs 1.0 (OR, 1.26; 95% CI, 0.70-2.28; P = .11). In post hoc exploratory analyses in the whole cohort, children with a 5-minute blood oxygen saturation (SpO₂) <80% were more likely to die or to have NDI (OR, 1.85; 95% CI, 1.07-3.2; P = .03).

CONCLUSIONS

Initial resuscitation of infants <32 weeks' gestation with initial FiO₂ 0.21 had no significant effect on death or NDI compared with initial FiO₂ 1.0. Further evaluation of optimum initial FiO₂, including SpO₂ targeting, in a large randomized controlled trial is needed.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Network Registry ACTRN 12610001059055 and the National Malaysian Research Registry NMRR-07-685-957.

Placental transfusion in preterm neonates of 30-33 weeks' gestation: a randomized controlled trial

OBJECTIVES

To compare effect of placental transfusion by delayed cord clamping (DCC) or cord milking (CM) with early cord clamping (ECC) on a composite of mortality or abnormal neurological status at 40 weeks' post-menstrual age (PMA) and 24-30 months' chronological age in neonates of 30-33 weeks' gestation.

STUDY DESIGN

Randomized, controlled trial.

OUTCOMES

A composite of mortality or abnormal neurological status at 40 weeks PMA and survival free of neurodevelopmental abnormalities at 24-30 months' chronological age.

RESULTS

A total of 461 neonates were randomized to placental transfusion (n = 233) or to ECC (n = 228). Among those assigned to placental transfusion group, 173 underwent DCC while in the remaining 60, CM was done. Incidence of mortality or abnormal neurological status at 40 weeks PMA (43 (18%) vs 35 (15%), RR (95% CI) 1.2 (0.8, 1.8), p = 0.4) and survival free of neurodevelopmental impairment at 24-30 months of chronological age (99 (47%) vs. 100 (50%); RR (95% CI): 0.9 (0.8, 1.2); P = 0.9) was similar between the study groups. The placental transfusion group showed a trend towards lower incidence of necrotizing enterocolitis.

CONCLUSION

In 30-33 weeks' gestation preterm neonates, placental transfusion as compared to early cord clamping resulted in similar mortality or abnormal neurological status at 40 weeks PMA and at 24-30 months of chronological age.

Delayed vs early umbilical cord clamping for preterm infants: a systematic review and meta-analysis

BACKGROUND

The effects of delayed cord clamping of the umbilical cord in preterm infants are unclear.

OBJECTIVE

We sought to compare the effects of delayed vs early cord clamping on hospital mortality (primary outcome) and morbidity in preterm infants using Cochrane Collaboration neonatal review group methodology.

STUDY DESIGN

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Chinese articles, cross-referencing citations, expert informants, and trial registries to July 31, 2017, for randomized controlled trials of delayed (≥30 seconds) vs early (<30 seconds) clamping in infants born <37 weeks' gestation. Before searching the literature, we specified that trials estimated to have cord milking in >20% of infants in any arm would be ineligible. Two reviewers independently selected studies, assessed bias, and extracted data. Relative risk (ie, risk ratio), risk difference, and mean difference with 95% confidence intervals were assessed by fixed effects models, heterogeneity by I² statistics, and the quality of evidence by Grading of Recommendations, Assessment, Development, and Evaluations.

RESULTS

Eighteen randomized controlled trials compared delayed vs early clamping in 2834 infants. Most infants allocated to have delayed clamping were assigned a delay of ≥60 seconds. Delayed clamping reduced hospital mortality (risk ratio, 0.68; 95% confidence interval, 0.52-0.90; risk difference, -0.03; 95% confidence interval, -0.05 to -0.01; P = .005; number needed to benefit, 33; 95% confidence interval, 20-100; Grading of Recommendations, Assessment, Development, and Evaluations = high, with I² = 0 indicating no heterogeneity). In 3 trials in 996 infants ≤28 weeks' gestation, delayed clamping reduced hospital mortality (risk ratio, 0.70; 95% confidence interval, 0.51-0.95; risk difference, -0.05; 95% confidence interval, -0.09 to -0.01; P = .02, number needed to benefit, 20; 95% confidence interval, 11-100; I² = 0). In subgroup analyses, delayed clamping reduced the incidence of low Apgar score at 1 minute, but not at 5 minutes, and did not reduce the incidence of intubation for resuscitation, admission temperature, mechanical ventilation, intraventricular hemorrhage, brain injury, chronic lung disease, patent ductus arteriosus, necrotizing enterocolitis, late onset sepsis or retinopathy of prematurity. Delayed clamping increased peak hematocrit by 2.73 percentage points (95% confidence interval, 1.94-3.52; P < .00001) and reduced the proportion of infants having blood transfusion by 10% (95% confidence interval, 6-13%; P < .00001). Potential harms of delayed clamping included polycythemia and hyperbilirubinemia.

CONCLUSION

This systematic review provides high-quality evidence that delayed clamping reduced hospital mortality, which supports current guidelines recommending delayed clamping in preterm infants. This review does not evaluate cord milking, which may also be of benefit. Analyses of individual patient data in these and other randomized controlled trials will be critically important in reliably evaluating important secondary outcomes.

The Research Cycle: Improving Care and Outcomes for Newborn Infants

Ensuring that policies and practice in perinatal care are informed by evidence from high-quality research is fundamental to improving outcomes for newborn infants and their families. Effective interventions in the perinatal period can have a life-long impact disproportionate to their costs. Many of the major advances in care that have transformed outcomes for preterm and sick newborn infants have been informed by empirical and applied health research. Conversely, there are examples of life-long adverse consequences for infants and families that are a legacy of practices based on poor-quality evidence. The challenge in the 21st century is to maintain the trajectory of improvements in care and outcomes. This will most likely be achieved via marginal gains from new or improved care practices underpinned by a range of research approaches, from preclinical and laboratory-based empirical studies that uncover pathogenic pathways or therapeutic mechanisms, to large-scale, applied research such as multicentre, randomised controlled trials. This will involve the coordination and collaboration of research efforts globally. Strategies to develop and prioritise research questions need to involve parents and families. Given the context in which much perinatal research is conducted, particularly in emergency situations around the time of birth, robust and transparent ethics and governance frameworks are essential to maintain the trust and engagement of communities. An ethical imperative exists to ensure that research output is disseminated effectively, and that effective and cost-effective interventions are implemented and integrated within a cycle that audits and benchmarks good practice and outcomes, and informs research evidence-based continuous quality improvement. This is the first in a series of articles on research methodology in neonatal medicine to be published in Neonatology, in response to a request from trainee researchers. We introduce the series by describing the research cycle, in particular how it is applied in neonatal medicine. Subsequent articles will cover translational research, clinical trials, diagnostic tests, global challenges, and the ethical issues relating to neonatal/perinatal research.

Delayed versus Immediate Cord Clamping in Preterm Infants

BACKGROUND

The preferred timing of umbilical-cord clamping in preterm infants is unclear.

METHODS

We randomly assigned fetuses from women who were expected to deliver before 30 weeks of gestation to either immediate clamping of the umbilical cord (≤10 seconds after delivery) or delayed clamping (≥60 seconds after delivery). The primary composite outcome was death or major morbidity (defined as severe brain injury on postnatal ultrasonography, severe retinopathy of prematurity, necrotizing enterocolitis, or late-onset sepsis) by 36 weeks of postmenstrual age. Analyses were performed on an intention-to-treat basis, accounting for multiple births.

RESULTS

Of 1634 fetuses that underwent randomization, 1566 were born alive before 30 weeks of gestation; of these, 782 were assigned to immediate cord clamping and 784 to delayed cord clamping. The median time between delivery and cord clamping was 5 seconds and 60 seconds in the respective groups. Complete data on the primary outcome were available for 1497 infants (95.6%). There was no significant difference in the incidence of the primary outcome between infants assigned to delayed clamping (37.0%) and those assigned to immediate clamping (37.2%) (relative risk, 1.00; 95% confidence interval, 0.88 to 1.13; P=0.96). The mortality was 6.4% in the delayed-clamping group and 9.0% in the immediate-clamping group (P=0.03 in unadjusted analyses; P=0.39 after post hoc adjustment for multiple secondary outcomes). There were no significant differences between the two groups in the incidences of chronic lung disease or other major morbidities.

CONCLUSIONS

Among preterm infants, delayed cord clamping did not result in a lower incidence of the combined outcome of death or major morbidity at 36 weeks of gestation than immediate cord clamping. (Funded by the Australian National Health and Medical Research Council [NHMRC] and the NHMRC Clinical Trials Centre; APTS Australian and New Zealand Clinical Trials Registry number, ACTRN12610000633088 .).

Impact of probiotics on necrotizing enterocolitis

A large number of randomized placebo-controlled clinical trials and cohort studies have demonstrated a decrease in the incidence of necrotizing enterocolitis with administration of probiotic microbes. These studies have prompted many neonatologists to adopt routine prophylactic administration of probiotics while others await more definitive studies and/or probiotic products with demonstrated purity and stable numbers of live organisms. Cross-contamination and inadequate sample size limit the value of further traditional placebo-controlled randomized controlled trials. Key areas for future research include mechanisms of protection, optimum probiotic species or strains (or combinations thereof) and duration of treatment, interactions between diet and the administered probiotic, and the influence of genetic polymorphisms in the mother and infant on probiotic response. Next generation probiotics selected based on bacterial genetics rather than ease of production and large cluster-randomized clinical trials hold great promise for NEC prevention.

Effectiveness of motor interventions in infants with cerebral palsy: a systematic review

AIM

To systematically review the evidence on the effectiveness of motor interventions for infants from birth to 2 years with a diagnosis of cerebral palsy or at high risk of it.

METHOD

Relevant literature was identified by searching journal article databases (PubMed, Embase, CINAHL, Cochrane, Web of Knowledge, and PEDro). Selection criteria included infants between the ages of birth and 2 years diagnosed with, or at risk of, cerebral palsy who received early motor intervention.

RESULTS

Thirty-four studies met the inclusion criteria, including 10 randomized controlled trials. Studies varied in quality, interventions, and participant inclusion criteria. Neurodevelopmental therapy was the most common intervention investigated either as the experimental or control assignment. The two interventions that had a moderate to large effect on motor outcomes (Cohen's effect size>0.7) had the common themes of child-initiated movement, environment modification/enrichment, and task-specific training.

INTERPRETATION

The published evidence for early motor intervention is limited by the lack of high-quality trials. There is some promising evidence that early intervention incorporating child-initiated movement (based on motor-learning principles and task specificity), parental education, and environment modification have a positive effect on motor development. Further research is crucial.

Outcomes of Two Trials of Oxygen-Saturation Targets in Preterm Infants

BACKGROUND

The safest ranges of oxygen saturation in preterm infants have been the subject of debate.

METHODS

In two trials, conducted in Australia and the United Kingdom, infants born before 28 weeks' gestation were randomly assigned to either a lower (85 to 89%) or a higher (91 to 95%) oxygen-saturation range. During enrollment, the oximeters were revised to correct a calibration-algorithm artifact. The primary outcome was death or disability at a corrected gestational age of 2 years; this outcome was evaluated among infants whose oxygen saturation was measured with any study oximeter in the Australian trial and those whose oxygen saturation was measured with a revised oximeter in the U.K. trial.

RESULTS

After 1135 infants in Australia and 973 infants in the United Kingdom had been enrolled in the trial, an interim analysis showed increased mortality at a corrected gestational age of 36 weeks, and enrollment was stopped. Death or disability in the Australian trial (with all oximeters included) occurred in 247 of 549 infants (45.0%) in the lower-target group versus 217 of 545 infants (39.8%) in the higher-target group (adjusted relative risk, 1.12; 95% confidence interval [CI], 0.98 to 1.27; P=0.10); death or disability in the U.K. trial (with only revised oximeters included) occurred in 185 of 366 infants (50.5%) in the lower-target group versus 164 of 357 infants (45.9%) in the higher-target group (adjusted relative risk, 1.10; 95% CI, 0.97 to 1.24; P=0.15). In post hoc combined, unadjusted analyses that included all oximeters, death or disability occurred in 492 of 1022 infants (48.1%) in the lower-target group versus 437 of 1013 infants (43.1%) in the higher-target group (relative risk, 1.11; 95% CI, 1.01 to 1.23; P=0.02), and death occurred in 222 of 1045 infants (21.2%) in the lower-target group versus 185 of 1045 infants (17.7%) in the higher-target group (relative risk, 1.20; 95% CI, 1.01 to 1.43; P=0.04). In the group in which revised oximeters were used, death or disability occurred in 287 of 580 infants (49.5%) in the lower-target group versus 248 of 563 infants (44.0%) in the higher-target group (relative risk, 1.12; 95% CI, 0.99 to 1.27; P=0.07), and death occurred in 144 of 587 infants (24.5%) versus 99 of 586 infants (16.9%) (relative risk, 1.45; 95% CI, 1.16 to 1.82; P=0.001).

CONCLUSIONS

Use of an oxygen-saturation target range of 85 to 89% versus 91 to 95% resulted in nonsignificantly higher rates of death or disability at 2 years in each trial but in significantly increased risks of this combined outcome and of death alone in post hoc combined analyses. (Funded by the Australian National Health and Medical Research Council and others; BOOST-II Current Controlled Trials number, ISRCTN00842661, and Australian New Zealand Clinical Trials Registry number, ACTRN12605000055606.).