FAIRFAX, VIRGINIA — , but researchers at the biennial meeting of the Diabetes in Pregnancy Study Group of North America expressed hope for more clarity in the near future and the ability to someday individualize treatment to account for what is increasingly viewed as a heterogeneous condition.
Until studies in 2015 and 2018 cast doubt on glyburide, “we used to have 80% [of our GDM patients] on glyburide, and 20% on insulin,” Maisa Feghali, MD, of the University of Pittsburgh, said during a discussion period. “Now we have 95% on insulin and 5% on oral hypoglycemics. I rely on insulin because I don’t have a better option, and I rely on research efforts [underway to provide better options]” in the future.
The American College of Obstetricians and Gynecologists recommends insulin as the preferred first-line pharmacologic therapy for GDM when pharmacologic therapy is needed, with metformin as an option when patients decline or cannot safely use insulin. Glyburide, ACOG said in its 2018 practice bulletin on GDM (Obstet Gynecol. 2018;131[2]:e49-64), should not be recommended as a first-line pharmacologic therapy.
The Society of Maternal-Fetal Medicine, on the other hand, has accepted metformin as a “reasonable and safe” first-line alternative to insulin — while recognizing that half of women will still require insulin to achieve glycemic control — and does not rule out consideration of glyburide. In its 2018 statement on the pharmacologic treatment of GDM, the society said that the evidence of benefit of one oral agent over another remains limited.
“When you have dueling guidelines, it means the data are not that clear,” George Saade, MD, professor and chair of obstetrics and gynecology at the Eastern Virginia School of Medicine, Norfolk, said in a presentation on GDM. An upcoming $12 million multicenter study to be led by the Ohio State University College of Medicine — coined the DECIDE trial — should provide clarity, he said.
The trial, funded by the Patient-Centered Outcomes Research Institute, which funds comparative clinical effectiveness research designed to be broadly applicable to practice, will enroll and randomize over 1500 pregnant individuals with GDM to either oral metformin or insulin and will follow mothers and children until 2 years after delivery.
The study’s primary and secondary hypotheses, respectively, are that metformin is not inferior to insulin in reducing a composite adverse neonatal outcome (large for gestational age, neonatal hypoglycemia and/or hyperbilirubemia) and that metformin does not result in increased child body mass index at 2 years, compared with insulin. It will also look at patient-reported factors associated with metformin use compared to insulin use — factors that “are important ... to enable clinical implementation of study findings,” said Dr. Saade, who played a role in designing the study over the past several years.
The study will take a pragmatic, real-world approach by ensuring racial and ethnic, socioeconomic, urban and rural, and geographic diversity at both large academic and community-based sites across the United States.
The trial, to be led by Mark Landon, MD, and Kartik Venkatesh, MD, PhD, of Ohio State University, will be the first large trial in the United States to both directly compare the ability of oral hypoglycemics and insulin to prevent GDM-associated pregnancy complications, and to follow children for 2 years, Dr. Saade said. “Prior research was either outside the United States, not randomized, not adequately powered, or had no long-term child follow-up,” he added after the meeting.