Poster Presentation International Association of the Diabetes and Pregnancy Study Groups 2022 - Hosted by ADIPS

PRECeDe Pilot: Prevention of neonatal Respiratory distress with antenatal corticosteroids prior to Elective Caesarean section in women with Diabetes – Can we blind participants, clinicians and researchers in a placebo-controlled randomised trial? (#131)

Amalia Karahalios 1 , Lex W Doyle 2 , Christopher J Yates 3 4 , Devaang A Kevat 3 , Rosalynn Pszczola 5 , Lee-anne Lynch 6 , Klea Atallah 2 , Joanne M Said 2 6
  1. Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia
  2. Obstetrics & Gynaecology, The University of Melbourne, Parkville, Victoria, Australia
  3. Diabetes and Endocrinology, Western Health, St Albans, VIC, Australia
  4. Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
  5. Newborn Services, Joan Kirner Women's & Children's at Sunshine Hospital, Western Health, St Albans, VIC, Australia
  6. Maternal Fetal Medicine, Joan Kirner Women's & Children's at Sunshine Hospital, Western Health, St Albans, VIC, Australia

INTRODUCTION

The PRECeDe Pilot Trial was designed to determine the feasibility of undertaking a larger multicentre, triple blind, placebo-controlled randomised trial (RCT) to assess the efficacy of administration of antenatal corticosteroids (ACS) within 7 days prior to elective caesarean section (CS) in women with pregestational diabetes (PGDM) or gestational diabetes (GDM) on maternal and neonatal outcomes. Hyperglycaemia following ACS administration is common and raises the concern that blinding participants and researchers in the RCT may not be feasible. We assessed blinding of treatment allocation for participants and staff within the pilot trial.

METHODS

We undertook a triple blind, placebo-controlled, pilot RCT at Western Health between June 2020 and May 2022 to assess the feasibility of undertaking a larger multicentre trial. The trial was registered prior to commencement of recruitment (ACTRN12619001475134) and institutional ethics approval obtained. Eligible participants with either PGDM or GDM were randomised to receive 2 injections of either betamethasone 11.4mg or normal saline placebo in identical masked syringes, 24 hours apart within 7 days prior to planned CS scheduled between 35+0 and 38+6 weeks’ gestation.

Participants, and clinical and research staff interacting with the patient were asked to predict which treatment group the participant was allocated to. Fleiss’s Kappa statistic (κ) was used to assess the agreement between participant or staff assessment and the true allocation.

RESULTS

Forty-seven women were recruited to the pilot trial with 22 participants allocated to receive betamethasone and 25 allocated to receive placebo.

There was moderate agreement between participant's prediction and their true treatment allocation (κ=0.69; 95% CI: 0.39, 0.98). Both the midwife administering the study medication (κ=0.84; 0.68,1.00) and the midwife collecting the research outcome data (κ=0.81; 0.54, 1.00) demonstrated the highest agreement with the true treatment allocation. Medical staff involved in the CS had poor agreement with the true treatment allocation (κ=0.24; -0.21, 0.71), followed by the endocrinologists involved in the titration of insulin (κ=0.33; -0.01, -0.67). Staff providing care on the postnatal ward demonstrated intermediate agreement (κ=0.43; -0.10, 0.96).

CONCLUSION

Blinding of participants was not optimal, however, clinicians providing clinical care antenatally and postnatally had poor agreement with the true allocation. Since these clinicians will make the decisions regarding patient care (maternal and neonatal), which will form the primary outcomes, it is feasible to proceed with a triple blinded study. We have identified strategies to improve the syringe masking to ensure that staff administering the study medication can remain blinded.