Gestational Diabetes Risk and Low Birth Weight After Metabolic Bariatric Surgery: a Complex Interplay to be Balanced

Area of Science:

• Obstetrics and Gynecology
• Endocrinology
• Bariatric Surgery

Background:

• Metabolic bariatric surgery (MBS) is recognized for improving obstetric outcomes and preventing gestational diabetes (GD) in women with obesity.
• The extent to which MBS reduces GD without introducing additional risks remains a critical area of concern for maternal and infant health.

Purpose of the Study:

• To evaluate the impact of metabolic bariatric surgery (MBS) on gestational diabetes (GD) prevalence and other pregnancy outcomes.
• To compare pregnancy outcomes in women who underwent MBS with those of matched non-operated controls.

Main Methods:

• A retrospective case-control study design was employed.
• Pregnancy outcomes of 79 women who previously underwent MBS were compared to 79 age- and preconception BMI-matched non-operated controls.

Main Results:

• Gestational diabetes (GD) was significantly less frequent in the MBS group (7.6% vs. 19%, p=0.03).
• Lower fasting blood glucose levels were observed in the first and second trimesters post-MBS.
• While small-for-gestational-age (SGA) was more frequent post-MBS, this difference was not significant after controlling for smoking habits. No significant differences were found in gestational weight gain, prematurity, or delivery mode.

Conclusions:

• Metabolic bariatric surgery (MBS) is associated with a lower prevalence of gestational diabetes (GD) compared to non-operated women with similar pre-pregnancy BMI.
• The reduction in GD post-MBS may be linked to lower birth weights, suggesting body weight-independent effects on glucose metabolism during pregnancy.
• These findings underscore the need to balance the benefits of MBS for maternal glucose regulation against potential impacts on fetal growth.