Pregnant women gradually develop insulin resistance during pregnancy, thereby ensuring sufficient nutrient supply for the growing foetus . In women with gestational diabetes mellitus (GDM), the insulin resistance leads to hyperglycaemia . The definition of GDM is glucose intolerance with onset or first recognition during pregnancy . Glucose passes through the placenta to the foetus and increases foetal insulin production, which, in turn, stimulates foetal growth, causing macrosomia and children large for gestational age (LGA) . In the short-term, GDM is associated with increased risk of adverse pregnancy outcomes with a following long-term risk of childhood obesity and type 2 diabetes in mother and offspring . The prevalence of GDM is rising , and so is the need for treatment.

Lifestyle changes are essential in the management of gestational diabetes. First-line treatment in GDM is medical nutrition therapy, together with weight management and physical activity . It has been suggested that lifestyle modification alone is sufficient to control blood glucose in 70–85% of the women that were diagnosed with GDM . How the diet should be composed for women with GDM is a complex matter and still not completely settled. In this review, we seek to provide an overview of the most important dietary interventions and components and how to treat and guide each woman with GDM during pregnancy.

Objectives:

To assess the effectiveness of modified diet chart and life style in the management of blood sugar levels among women with gestational diabetes mellitus

Novelty:

Lifestyle changes are essential in the management of gestational diabetes. First-line treatment in GDM is medical nutrition therapy, together with weight management and physical activity. It has been suggested that lifestyle modification alone is sufficient to control blood glucose in 70–85% of the women that were diagnosed with GDM . How the diet should be composed for women with GDM is a complex matter and still not completely settled. In this review, we seek to provide an overview of the most important dietary interventions and components and how to treat and guide each woman with GDM during pregnancy.

Applicability:

Long term

Inclusion criteria:

Pregnant women who are diagnosed with gestational diabetes mellitus after 24 – 28 weeks of pregnancy  attending to obstetric outpatient department of Government Maternity Hospital, Tirupati,

Exclusion criteria -

Pregnant women who are associated with medical disorders.

Study location: Pregnant women who are attending to obstetric outpatient department of Government Maternity Hospital, Tirupati, Andhra Pradesh

Study duration: one year

Study design: Randomized open label trial

Study population: Pregnant women who are diagnosed with gestational diabetes mellitus after 24 weeks of pregnancy attending to obstetric outpatient department of Government Maternity Hospital, Tirupati.

Sampling technique: Initially we will check the eligibility criteria of the participants and make a list of the potential participants. From the list, we will randomly select a pool for recruitment and randomization.

Sample size calculation:

Assuming superiority margin as 5%, power 80% at 5% significance level, with 1:1 allocation for cases and controls, and 10% of drop out in each group, we require 100 participants in the intervention arm and 100 participants in the control arm.

Randomization:

We will use block randomization with a block size of 4 to allocate 2 participants in the intervention arm and 2 participants in the control arm. Thus, we require a total 50 blocks to complete the randomization process. The blocks will be selected randomly to determine the participants’ allotment.

Bio chemical estimations: Fasting blood sugar levels and post prandial blood sugar levels at 15 days once and HbA1C levels after 3 months

Anthropometric measurements: Height at enrolment and weight and BMI at every 25 days visit

Interventions: Modified diet chart and life style

Intervention   schedule:    modified diet chart and exercised daily for   3months

Data collection

• Pregnant women who are attending to GMH OPD and diagnosed to have gestational diabetes will be recruited and explained about modified diet chart and lifestyle to be followed and asked to follow.
• Regular attendance  record will be  maintained  during  the study every 15 days once visit. Participants attending<70%ofthepregnant women ,will be excluded from the analysis.
• After the completion of usage of diet chart and life style, participants will be motivated to continue the same practice daily at home.
• Compliance to diet chart and life style will be ensured by making a phone call once in three days .

Statistical analysis  plan:

• Data entry willbedoneelectronically throughtablet-basedcasereportform(CRF).
• SPSSversion 26 willbeusedforanalysisofthedata.
• Descriptivestatisticswillbepresentedbypercentage(%)withappropriate95% confidence interval (CI), meanwith standarddeviation(SD)or medianandinterquartilerange (IQR).
• To check the difference in the baseline characteristics, we will apply- chi-square test for the categorical variables andunpairedt-testfor the continuousvariables.
• The primary outcome of blood sugar levels will be expressed as the mean with SD or median with IQR.Wewillcalculatetheproportion of participants with decrease in blood sugar levels from the baseline in both the intervention arm and the control armseparately with appropriate 95% CI.
• Ap-valueof<0.05willbeconsidered asstaticallysignificantforallthestatisticaltests.

• Blood sugar levels:For boththe groups, we will calculate the pre-treatment andpost-treatment absolute fasting and post prondal blood sugar levels withappropriate95%CIandthedifferencebetween the twogroupsby appropriate statisticaltest.

Expected Outcomes

1. We can provide a diet chart and lifestyle module to all pregnant women attending to GMH OPD
2. We can include the diet chart and lifestyle modifications in the counselingsessionsofthe pregnant women.
3. Timelines: Durationofthestudy:18 months.

1.       Budget:

Age distribution

The table presents the age range and average age of participants in both study groups. Women in the Regular Diet group were between 18 and 39 years old, with a mean age of 25.4 years (±4.5 SD). Those in the Modified Diet group were aged 18 to 36 years, with a slightly higher mean age of 26.2 years (±3.9 SD). The p-value of 0.16 indicates that this small difference in average age between the two groups was not statistically significant, confirming that the groups were well-matched in terms of age at the start of the study.

Distribution of some categorical variables

*Statistically significant

This table compares baseline and outcome characteristics between the two groups. Parity (whether women were having their first or a subsequent baby) and the sex of the newborn were evenly distributed, with no significant differences. The rate of admission to the Neonatal Intensive Care Unit (NICU) was also not significantly different. However, the type of delivery showed a significant difference (p=0.02). A higher percentage of women in the Modified Diet group (55.8%) had a vaginal delivery compared to the Regular Diet group (44.2%), while the Regular Diet group had a higher rate of Cesarean sections (60.6% vs. 39.4%).

Mean FBS levels at three time periods in mg/dl

This table displays the Fasting Blood Sugar levels at three time points for each group. For the Regular Diet group, the mean FBS decreased from 117.3 mg/dl at baseline to 109.8 mg/dl and finally to 102.3 mg/dl. The Modified Diet group started at a slightly lower baseline of 114.5 mg/dl and showed a more pronounced decrease to 104.0 mg/dl and then to 89.1 mg/dl. The final mean FBS in the Modified Diet group was notably lower.

Mean PPBS levels at three time periods in mg/dl

This table shows the Postprandial Blood Sugar levels over three periods. Both groups started with similar high baseline means (Regular: 170.5 mg/dl, Modified: 169.0 mg/dl). The Regular Diet group's levels reduced to 162.4 mg/dl and then 150.9 mg/dl. The Modified Diet group demonstrated a steeper decline, with levels falling to 154.3 mg/dl and then to 135.4 mg/dl, achieving a much lower final mean PPBS.

Pair wise comparison of FBS at 3 time periods among regular diet group by Repeated measures ANOVA test

• Mean FBS baseline = 117.3 mg/dl
• Mean FBS second = 109.8 mg/dl
• Mean FBS third = = 102.3 mg/dl

this table confirms that within the Regular Diet group, the observed decrease in FBS levels across all three time points was statistically significant (p<0.001 for all pairwise comparisons: baseline vs. second, baseline vs. third, and second vs. third). The mean differences (e.g., a 14.9 mg/dl drop from baseline to the third measurement) were all significant.

Comparison of FBS at 3 time periods among modified diet group by Repeated measures ANOVA test

• Mean FBS baseline = 114.5 mg/dl
• Mean FBS second = 104.0 mg/dl
• Mean FBS third = = 89.1 mg/dl

This analysis for the Modified Diet group also shows statistically significant reductions in FBS over time (p<0.001 for all comparisons). The magnitude of the mean differences was larger than in the Regular Diet group, most notably a 25.4 mg/dl decrease from baseline to the third measurement, compared to 14.9 mg/dl in the regular group.

Comparison of PPBS at 3 time periods among regular diet group by Repeated measures ANOVA test

• Mean PPBS baseline = 170.5 mg/dl
• Mean PPBS second = 162.4 mg/dl
• Mean PPBS third = = 150.9 mg/dl

The analysis indicates that PPBS levels significantly decreased over time within the Regular Diet group (p<0.001). The mean difference from baseline to the final measurement was 19.6 mg/dl, confirming a statistically significant improvement even with standard care.

Comparison of PPBS at 3 time periods among modified diet group by Repeated measures ANOVA test

• Mean PPBS baseline = 169.0 mg/dl
• Mean PPBS second = 154.3 mg/dl
• Mean PPBS third = = 135.4 mg/dl

For the Modified Diet group, the reductions in PPBS were both statistically significant (p<0.001) and substantially greater in magnitude than in the Regular Diet group. The key difference from baseline to the final measurement was 33.6 mg/dl, which is markedly larger than the 19.6 mg/dl reduction seen in the control group.

This randomized open-label study demonstrates that a structured modified diet chart combined with lifestyle intervention is more effective than routine dietary advice in improving glycaemic control among women with gestational diabetes mellitus. Although both groups showed significant reductions in fasting and post-prandial blood glucose levels, the magnitude of reduction was consistently greater in the modified diet group. Improved glycaemic control likely contributed to the higher rate of vaginal deliveries observed in the intervention arm. These findings reinforce the importance of medical nutrition therapy as the cornerstone of GDM management and highlight its potential role in reducing obstetric complications and future cardiometabolic risk.

The study concludes that a structured modified diet chart with lifestyle modification significantly improves fasting and post-prandial blood glucose levels in women with gestational diabetes mellitus compared with standard dietary advice. The intervention was also associated with a higher rate of vaginal delivery, suggesting better maternal outcomes. As medical nutrition therapy is a safe, cost-effective, and non-pharmacological approach, its integration into routine antenatal care can strengthen GDM management. Early dietary intervention during pregnancy may help reduce immediate pregnancy-related complications and contribute to lowering long-term cardiometabolic risk in both mothers and their offspring.

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