Dietary Fiber Cut Gestational Diabetes, Preterm Birth

Researchers published the study covered in this summary on Research Square as a preprint that has not yet been peer reviewed.

Key Takeaways

  • Pregnant women who had a high level of insulin resistance according to their triglyceride and glucose (TyG) index prior to 20 weeks’ gestation showed improved glucose metabolism, a reduced risk for gestational diabetes, and significantly fewer preterm births when treated daily with an oral fiber supplement for 5 weeks (gestational weeks 20-24) compared with untreated controls in a single-center, randomized study with 295 women.

  • The fiber supplement intervention did not affect lipid profiles or other maternal and neonatal outcomes.

Why This Matters

  • Women who develop gestational diabetes are at risk for maternal and perinatal complications and for type 2 diabetes later in life.

  • High TyG index in the first trimester is associated with gestational diabetes development.

  • Improving glucose metabolism in women with a high TyG index during pregnancy might help prevent gestational diabetes.

Study Design

  • The study randomly assigned 295 women with a TyG index ≥ 8.5 before 20 weeks’ gestation seen at the Department of Obstetrics and Gynecology at the Shanghai General Hospital during June 2021 to July 2022.

  • During gestational weeks 20-24, 97 women received a 12-g dose of oral dietary fiber powder twice daily, and 197 served as controls and received usual care without the fiber supplement. All participants received guidance on how to optimize diet and activity. Forty-six women either dropped out or were lost to follow-up prior to delivery.

  • Participants underwent a 75-g oral glucose tolerance test at 25-28 weeks’ gestational age and also underwent additional testing.

Key Results

  • The incidence of gestational diabetes among women in the group who ingested the fiber supplement was 11.2%, significantly less than the 23.7% rate among women who served as controls.

  • The average 2-hour blood glucose levels during the oral glucose tolerance test  was 6.45 mmol/L among the women using the fiber supplement and 6.69 mmol/L among the control group, a significant difference.

  • The researchers found no significant differences in levels of fasting blood glucose, 1-hour blood glucose, lipid profiles, or TyG index between the treatment groups.

  • Pre- and post-intervention weight and body mass index values showed no significant differences between the two treatment groups.

  • Mean gestational age at delivery among women who received the fiber supplement was 39.07 weeks, significantly greater than the 38.58-week average among the controls.

  • The incidence of preterm delivery at less than 37 weeks was 2.3% among women who used the fiber supplement, significantly less than the 9.4% rate among the controls.


  • This was a single-center, pilot study that involved a relatively small number of women.

  • Intervention with supplemental dietary fiber was for only 5 weeks during pregnancy.


  • The study received no commercial funding.

  • None of the authors had disclosures.

This is a summary of a preprint research study The Role of Dietary Fiber on Preventing Gestational Diabetes Mellitus in an At-Risk Group of High Triglyceride-Glucose Index Women: A Randomized Controlled Trial,” by researchers at Shanghai General Hospital, China on Research Square provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on

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