Gestational diabetes mellitus (GDM),characterized by elevated blood glucose levels detected during pregnancy,poses risks to both mother and child. Understanding preventative measures is crucial for healthier pregnancies.

During pregnancy, a woman’s metabolism adapts to nourish the developing baby. Insulin sensitivity typically increases in the first trimester but decreases in the second and third. Women who develop GDM experience a blunted initial increase in insulin sensitivity,followed by a more pronounced reduction later in pregnancy,leading to hyperglycemia. Elevated fat levels in the blood may also contribute to the baby’s increased size.

GDM increases the likelihood of pregnancy complications such as high blood pressure and induced labor. Moreover, women with GDM face a higher lifetime risk of developing type 2 diabetes. Infants born to mothers with GDM are more prone to macrosomia (large birth size), perhaps leading to birth injuries, breathing difficulties, jaundice, low blood sugar, and later-life obesity and diabetes.

given the numerous risk factors associated with GDM, interventions before and during pregnancy hold promise for reducing its incidence. A summary of evidence from randomized controlled trials on interventions that might prevent GDM was reviewed.

Key Findings on GDM Prevention

“Women with GDM are more likely to develop complications in pregnancy including high blood pressure and need labor to be induced.”

Research encompassing 71 randomized controlled trials with 23,154 pregnant women was analyzed. The studies investigated various interventions, including diet, exercise, dietary supplements, medications, and management of pre-existing health conditions. The quality of evidence varied from very low to high.

Impact of Diet and Exercise

Combining diet and exercise showed a potential reduction in GDM risk compared to standard care, according to 19 trials involving 6633 women. The evidence was rated as moderate quality.

However, the effect of dietary advice alone (5 trials; 1279 women; very low-quality evidence), a low glycemic index diet compared to a moderate-to-high glycemic index diet (4 trials; 912 women; low-quality evidence), and exercise alone (3 trials; 826 women; low-quality evidence) on GDM risk remained unclear.

Role of Dietary Supplements

Omega-3 fatty acid supplementation during pregnancy demonstrated no impact on GDM risk in 12 trials involving 5235 women (high-quality evidence).

Myo-inositol supplementation during pregnancy possibly reduced the risk of GDM, based on 3 trials with 502 women (low-quality evidence).

Vitamin D supplementation during pregnancy showed a possible benefit in reducing GDM risk in 4 trials with 446 women (low-quality evidence). Notably, these trials were conducted in Asian countries, and the women’s pre-supplementation vitamin D levels were largely unknown.

The effect of vitamin D given with calcium supplementation,or with calcium plus other minerals,was unclear. Similarly, probiotics combined with dietary intervention had an unclear effect on GDM risk.

medication Interventions

The medication metformin showed a potential benefit in reducing GDM risk when administered to obese pregnant women, according to 3 trials involving 892 women (moderate-quality evidence).

Low- to very low-quality evidence from eight small trials indicated an unclear effect on GDM risk for heparin, aspirin, leukocyte immunization, or immunoglobulin (IgG) given to women with a history of stillbirth.

Managing Other Health Issues

Global screening for thyroid problems, compared to risk-based screening, had no impact on GDM risk in one trial involving 4516 women (moderate-quality evidence). Two different approaches to managing maternal asthma also showed unclear effects (low-quality evidence).