Gestational Diabetes Mellitus (GDM) is a growing global health concern characterized by glucose intolerance first recognized during pregnancy. Its increasing incidence is attributed to rising maternal age, obesity, and sedentary lifestyles. GDM poses significant risks for both mother and neonate, including hypertensive disorders, caesarean delivery, neonatal hypoglycaemia, and long-term metabolic complications [1]. While Insulin has traditionally been the mainstay treatment for GDM, Metformin has emerged as a viable alternative due to its oral administration, cost-effectiveness, and favourable maternal and neonatal safety profile.

Previous studies have explored the comparative effectiveness of Metformin and Insulin, yet limited data exist in the Indian population evaluating maternal and neonatal outcomes across different treatment modalities [2,3]. By correlating clinical outcomes with existing literature and risk profiles, this study strengthens the understanding of optimal GDM management in the Indian context, where culturally specific data are critically needed. The objectives of the study were: (1) to identify treatment modalities used in GDM management; (2) to observe associated maternal and neonatal outcomes; (3) to identify risk factors influencing these outcomes; and (4) to educate the patients on the importance of adherence and compliance to the treatment.

A single centered, hospital based, observational study was conducted in the Department of Obstetrics and Gynaecology and Department of Paediatrics and Neonatology, Pushpagiri Medical College Hospital, Thiruvalla, Kerala, India for a duration of 6 months, including a total of 110 GDM patients.

Inclusion Criteria

·       All women diagnosed with GDM aged between 20 - 40 years with a gestation period of 28 - 40 weeks.

·       Those who gave consent voluntarily to participate in the study.

Exclusion Criteria

·       Multiple pregnancy (including previous pregnancy)

·       Patients who were not willing to give consent.

The sample size obtained was n ₌110 GDM patients using the formula;

Sample size, n = (Zα²) PQ

d2

STUDY PROCEDURE

The study “An Observational Study on Maternal and Neonatal Outcomes in Patients with Gestational Diabetes Mellitus Treated with Metformin and Insulin” was conducted after getting approval from the Institutional Ethics Committee. Participants were informed about the study and confidentiality measures, and written informed consent was obtained. Subjects were selected based on specific inclusion and exclusion criteria. Data was collected using a structured questionnaire covering health history, lifestyle, mental health, and treatment. An educational leaflet was also provided to emphasize the importance of treatment adherence for better maternal and neonatal outcomes.

STATISTICAL ANALYSIS

Data were coded and entered in Microsoft Excel and analysed using SPSS version 23. Continuous variables were summarized using t-tests or ANOVA. Categorical variables were presented as frequencies and percentages. Associations between categorical variables and outcomes were analysed using the Chi-square or Fisher’s exact test. A p-value <0.05 was considered statistically significant.

Factors associated with neonatal hypoglycaemia

A higher maternal BMI was significantly associated with neonatal hypoglycaemia (p=0.002).

Figure 1: Distribution of study population based on treatment modality followed

Figure 2: Distribution of study population based on maternal complications

Figure 3: Distribution of study population based on fetal complications

Table 1: Distribution of study population based on treatment modality followed and maternal complications

Table 2: Distribution of study population based on fetal complications

Table 3: Factors associated with induction of labor requirement

Table 4: Factors associated with polyhydramnios

Table 5: Factors associated with jaundice in newborn

In this study, the majority of participants were aged 26–30 years and had insulin resistance. Higher BMI and a family history of diabetes were more common in the Insulin group, along with PCOD and fertility treatment, indicating greater metabolic risk [4,5]. Metformin was the most commonly used drug (56.4%), reflecting a shift in clinical practice toward its favorable profile. Cesarean section rates were highest among Insulin-treated women (100%), with significantly lower rates in the Metformin group (43.5%) (p=0.001) [6]. Labor induction was more frequent in the Metformin and combination groups, possibly due to better glycemic control. Overall, Metformin was associated with fewer maternal complications [7,8].

Neonatal outcomes showed high NICU admission rates across all groups (>88%), likely due to precautionary institutional protocols [9]. Neonatal hypoglycemia was more frequent in the Insulin group (11.1%) versus the Metformin (4.8%) [10]. No notable differences were found in birth weight or jaundice rates [6]. Compared with prior studies, Vidyasri Bailore et al., (2024) [11], Abdel Monem Mohamad Zakaria et al., (2022) [12], Federico Pigato et al., (2019) [13], Slagjana Simeonova-Krstevska et al., (2018) [14], Metformin demonstrated a safer maternal-neonatal profile, including fewer complications and interventions. These findings support Metformin as a strong first-line option for GDM management, though further research on institutional practices, long-term outcomes is warranted and individualized treatment remains essential [15].

This study underscores the significant impact of GDM on maternal and neonatal health. Key findings include a high caesarean section rate, especially in the Insulin-only group, suggesting more severe metabolic conditions. In contrast, Metformin use was associated with fewer maternal complications and lower caesarean rates, indicating more favourable pregnancy outcomes when glycaemic control is achieved. Neonatal hypoglycaemia was more frequent in the Insulin group, supporting concerns about fetal hyperinsulinism. High NICU admission rates across all groups were likely influenced by hospital policy rather than clinical necessity. Risk factors such as a family history of diabetes and prior GDM were more common in women requiring Insulin or combination therapy, highlighting the need for more intensive management in these cases. Overall, the study supports Metformin as a safe, cost-effective, and convenient treatment option for many women with GDM. However, individualized care remains essential.

ACKNOWLEDGEMENT

This acknowledgment expresses heartfelt gratitude to all those who supported the completion of the thesis. The authors first thank God for strength and guidance. They acknowledge the management and leadership of Pushpagiri College of Pharmacy and Pushpagiri Medical College Hospital for their permission and support. Special thanks go to their principal, research guide Dr. Malini S, and clinical guides Dr. Susan Mathew and Dr. Jacob Abraham for their mentorship and expertise. Appreciation is also extended to Dr. Rosin George Varghese for statistical assistance, and faculty members for their help during the academic journey.

Conflict of Interest

The authors declared no potential conflicts of interest concerning the research, authorship, and/publication of this article.

Funding

The authors received no financial support for the research, authorship, and/ publication of this article.

Ethical consideration

Institutional Research/ Human Ethics Committee approval was obtained.

1.      Buchanan, Thomas A., and Anny H. Xiang. ‘Gestational Diabetes Mellitus’. Journal of Clinical Investigation, vol. 115, no. 3, Mar. 2005, pp. 485–91.

2.      Wicklow, Brandy, and Ravi Retnakaran. ‘Gestational Diabetes Mellitus and Its Implications across the Life Span’. Diabetes & Metabolism Journal, vol. 47, no. 3, May 2023, pp. 333–44.

3.      McMicking, Jess, et al. ‘Epidemiology and Classification of Diabetes in Pregnancy’. The Global Library of Women’s Medicine, 2021.

4.      Chakraborty, Aditi, and Suryakant Yadav. ‘Prevalence and Determinants of Gestational Diabetes Mellitus among Pregnant Women in India: An Analysis of National Family Health Survey Data’. BMC Women’s Health, vol. 24, no. 1, Feb. 2024, p. 147.

5.      Choudhury, Abbas Alam, and V. Devi Rajeswari. ‘Gestational Diabetes Mellitus - A Metabolic and Reproductive Disorder’. Biomedicine & Pharmacotherapy, vol. 143, Nov. 2021, p. 112183.

6.      “High Blood Sugar during Pregnancy: What to Do-Gestational Diabetes Diagnosis & Treatment.” Mayo Clinic, https://www.mayoclinic.org/diseases conditions/gestational- diabetes/diagnosis-treatment/drc-20355345. Accessed 17 Dec. 2024

7.      Gestational Diabetes Mellitus (GDM). 19 https://www.hopkinsmedicine.org/health/ conditions-and diseases/diabetes/gestational-diabetes.

8.      Amiri, Fatemeh Nasiri, et al. “Risk Factors for Gestational Diabetes Mellitus: A Case- Control Study.” American Journal of Lifestyle Medicine, vol. 15, no. 2, Aug. 2018, pp. 184–90.

9.      “Tests & Diagnosis for Gestational Diabetes - NIDDK.” National Institute of Diabetes and Digestive and Kidney Diseases, https://www.niddk.nih.gov/health-information/ diabetes/overview/what-is diabetes/gestational/tests-diagnosis. Accessed 17 Dec. 2024.

10.   MD, Dr Ananya Mandal. “Gestational Diabetes Pathophysiology.” News Medical, 1 Nov.2010,https://www.news-medical.net/health/Gestational Diabetes Pathophysiology

11.   Bailore, Vidyasri, et al. “Adverse Pregnancy Outcomes with Respect to Treatment modalities in Women with Gestational Diabetes Mellitus at a Rural Tertiary Care Teaching Hospital.” Journal of Family Medicine and Primary Care, vol. 13, no. 8, Aug. 2024, pp. 2986–92.

12.   Zakaria, Abdel Monem Mohamed, et al. “Maternal and Neonatal Outcomes in Pregnant Women with Gestational Diabetes Mellitus Treated with Diet, Metformin or Insulin.” International Journal of Health Sciences, vol. 6, no. S4, June 2022, pp. 2941–51.

13.   Pigato, Federico, et al. “Gestational Diabetes Mellitus: Impact of Adherence on Patient Management and Maternal-Neonatal Complications.” Primary Care Diabetes, vol. 17, no. 5, Oct. 2019, pp. 486–92.

14.   Simeonova-Krstevska, Slagjana, et al. “Maternal and Neonatal Outcomes in Pregnant Women with Gestational Diabetes Mellitus Treated with Diet, Metformin or Insulin.” Open Access Macedonian Journal of Medical Sciences, vol. 6, no. 5, May 2018, pp. 803–07.

15.   “Tests & Diagnosis for Gestational Diabetes - NIDDK.” National Institute of Diabetes and Digestive and Kidney Diseases, https://www.niddk.nih.gov/health-information/ diabetes/overview/what-is diabetes/gestational/tests-diagnosis. Accessed 17 Dec. 2024.