Essential variables for reporting research studies on fetal growth restriction: a Delphi consensus

OBJECTIVE: To achieve consensus on the minimum reporting set of study variables for fetal growth restriction (FGR) research studies. Determination of a list of variables considered essential to be reported independent of a specific hypothesis is likely to improve the study quality by inclusion of essential end-points, enhancing the consistency among studies and minimizing potential confounding. This in turn can accelerate generation of generalizable knowledge either by standardization of individual study designs or by enhancing the possibility of individual patient data meta-analysis merging a number of uniformly structured datasets.STUDY DESIGN: An expert panel, identified based on their publication record as lead or senior authors in studies of FGR, was requested to select a set of essential study parameters from a literature-based list utilizing the Delphi consensus methodology. We collected responses in four consecutive rounds by online questionnaires presented to panelists through a unique token-secured link for each round. Variables were selected in three rounds based on the concurrence on Likert scale scoring. In the final round, retained parameters were categorized as essential (to be reported in all FGR studies) or recommended (important but not mandatory).RESULTS: 87/100 experts agreed to participate and 62 (71%) completed all four rounds. Agreement was reached for 16 essential and 30 recommended parameters including maternal characteristics, prenatal investigations, management and pregnancy/neonatal outcomes. Essential parameters included hypertensive complications in the current pregnancy, smoking, parity, maternal age, abdominal circumference, estimated fetal weight, umbilical artery Doppler (pulsatility index and end-diastolic flow), middle cerebral artery Doppler, indications for intervention, pregnancy outcome (live birth, stillbirth or neonatal death), gestational age at delivery, birthweight, birthweight centile, mode of delivery and Apgar score at 5 minutes.CONCLUSIONS: We present a list of essential and recommended parameters that characterize FGR independent of study hypotheses. Uniform reporting of these variables in prospective clinical research is expected to improve data quality, study consistency and ultimately our understanding of FGR. This article is protected by copyright. All rights reserved.