Variation in outcome reporting in randomized controlled trials of interventions for prevention and treatment of fetal growth restriction

OBJECTIVE

Although fetal growth restriction (FGR) is well known to be associated with adverse outcomes for the mother and offspring, effective interventions for the management of FGR are yet to be established. Trials reporting interventions for the prevention and treatment of FGR may be limited by heterogeneity in the underlying pathophysiology. The aim of this study was to conduct a systematic review of outcomes reported in randomized controlled trials (RCTs) assessing interventions for the prevention or treatment of FGR, in order to identify and categorize the variation in outcome reporting.

METHODS

MEDLINE, EMBASE and The Cochrane Library were searched from inception until August 2018 for RCTs investigating therapies for the prevention and treatment of FGR. Studies were assessed systematically and data on outcomes that were reported in the included studies were extracted and categorized. The methodological quality of the included studies was assessed using the Jadad score.

RESULTS

The search identified 2609 citations, of which 153 were selected for full-text review and 72 studies (68 trials) were included in the final analysis. There were 44 trials relating to the prevention of FGR and 24 trials investigating interventions for the treatment of FGR. The mean Jadad score of all studies was 3.07, and only nine of them received a score of 5. We identified 238 outcomes across the included studies. The most commonly reported were birth weight (88.2%), gestational age at birth (72.1%) and small-for-gestational age (67.6%). Few studies reported on any measure of neonatal morbidity (27.9%), while adverse effects of the interventions were reported in only 17.6% of trials.

CONCLUSIONS

There is significant variation in outcome reporting across RCTs of therapies for the prevention and treatment of FGR. The clinical applicability of future research would be enhanced by the development of a core outcome set for use in future trials. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Consensus definition and essential reporting parameters of selective fetal growth restriction in twin pregnancy: a Delphi procedure

OBJECTIVES

Twin pregnancy complicated by selective fetal growth restriction (sFGR) is associated with increased perinatal mortality and morbidity. Inconsistencies in the diagnostic criteria for sFGR employed in existing studies hinder the ability to compare or combine their findings. It is therefore challenging to establish robust evidence-based management or monitoring pathways for these pregnancies. The main aim of this study was to determine, by expert consensus using a Delphi procedure, the key diagnostic features of and the essential reporting parameters in sFGR.

METHODS

A Delphi process was conducted among an international panel of experts in sFGR in twin pregnancy. Panel members were provided with a list of literature-based parameters for diagnosing sFGR and were asked to rate their importance on a five-point Likert scale. Parameters were described as solitary (sufficient to diagnose sFGR, even if all other parameters are normal) or contributory (those that require other abnormal parameter(s) to be present for the diagnosis of sFGR). Consensus was sought to determine the cut-off values for accepted parameters, as well as parameters used in the monitoring, management and assessment of outcome of twin pregnancy complicated by sFGR. The questions were presented in two separate categories according to chorionicity.

RESULTS

A total of 72 experts were approached, of whom 60 agreed to participate and entered the first round; 48 (80%) completed all four rounds. For the definition of sFGR irrespective of chorionicity, one solitary parameter (estimated fetal weight (EFW) of one twin < 3^rd centile) was agreed. For monochorionic twin pregnancy, at least two out of four contributory parameters (EFW of one twin < 10^th centile, abdominal circumference of one twin < 10^th centile, EFW discordance of ≥ 25%, and umbilical artery pulsatility index of the smaller twin > 95^th centile) were agreed. For sFGR in dichorionic twin pregnancy, at least two out of three contributory parameters (EFW of one twin < 10^th centile, EFW discordance of ≥ 25%, and umbilical artery pulsatility index of the smaller twin > 95^th centile) were agreed.

CONCLUSIONS

Consensus-based diagnostic features of sFGR in both monochorionic and dichorionic twin pregnancies, as well as cut-off values for the parameters involved, were agreed upon by a panel of experts. Future studies are needed to validate these diagnostic features before they can be used in clinical trials of interventions. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.