Comprehensive Gestational Diabetes Mellitus Care

Background

Gestational diabetes mellitus (GDM) is any degree of glucose intolerance first recognized during pregnancy regardless of the degree of hyperglycemia¹. More than 21 million (16.7%) of live births per year are affected by maternal diabetes, globally of which 90% are GDM². GDM is associated with an increased risk of large-for-gestational-age birth weight and neonatal and pregnancy complications. Moreover, women with GDM and their offspring are at higher risk of developing type 2 diabetes later in life and childhood obesity. Since perinatal complications and stillbirth risk can be reduced effectively by treatment, screening of GDM is a matter of utmost importance.

To augment comprehensive GDM care in Yangon General Hospital (YGH), GDM clinic (every Tuesday) was started in January 2018 under department of diabetes and endocrinology, YGH with the collaboration of obstetricians from Central Women Hospital (CWH), as part of the activity of Diabetes Centers of Excellence in Myanmar. Since the prevalence of GDM varies widely, depending on the diagnostic criteria used, standardization of diagnostic criteria for GDM testing across Yangon Division was optimized. There were also upgrading of GDM clinic records and treatment algorithm, postpartum follow-up program, postpartum OGTT screening. Public education was performed through facebook page of GDM (YGH) with aid of interprofessional team (YGH, CWH, Improving Global Health UK).

After the COVID 19 era, the GDM clinic reopens every Thursday (9-12 am) at YGH. Follow-ups are arranged every two weeks as necessary. Patient education section is done weekly. Fig.1 shows the total number of pregnant women with diabetes attending to YGH GDM clinic each year.

Screening and Diagnosis¹^,3

On the first prenatal visit, all pregnant women should be evaluated for risk factors for diabetes and those with high-risk factors should be screened by 75-gram oral glucose tolerance test (OGTT). The OGTT is repeated at 24-28 weeks of gestation if the first test is negative.

Women who do not meet low or high-risk criteria should be screened at 24-28 weeks of gestation. If the test is positive at any point, protocol of management should be followed as given in this guideline.

In women with low risk for gestational diabetes, screening is not advisable.

Criteria for high risk are as follows:⁴

• BMI above 30 kg/m2
• Previous big baby weighing ≥4.5 kg/9.9lb
• Previous GDM
• First-degree relative with diabetes
• Family origin with a high prevalence of diabetes (South Asian)
• History of poor obstetric outcome (eg. unexplained stillbirth/perinatal death)

Criteria for low risk are as follows:⁴

• Age <25 years
• Weight normal before pregnancy
• No history of abnormal glucose metabolism and
• No history of poor obstetric outcome

Screening is done by performing a 75 g OGTT (75 g anhydrous glucose powder or 82.5 g monohydrous glucose) one step strategy with plasma glucose measurement on fasting, 1hr and 2hr in women who were not previously diagnosed with overt diabetes

Management during pregnancy

Lifestyle and Behavioral Management

Medical nutrition therapy (MNT), physical activity and weight optimization are sufficient to control the glycemic status in 70–85% of women with GDM. MNT primarily involves a carbohydrate controlled balanced meal plan which promotes fetal/neonatal and maternal health, achieve glycemic goals, and promote appropriate weight gain.

The recommended diet includes mainly low-glycemic-index carbohydrates and often apportions daily caloric intake into three main meals and 2–4 snacks. The National Academy of Medicine recommends a diet about a minimum of 175 g of carbohydrate (35% of a 2,000-calorie diet), 71 g of protein, and 28 g of fiber and monounsaturated and polyunsaturated fats.

Take effective exercise (aerobic, resistance, or both for 20–50 min/day, 2–7 days/week of moderate intensity) to improve blood glucose control.

Medical Therapy

• Metformin or Insulin therapy is the accepted medical management when blood glucose targets are not met by modification in diet and exercise within 1-2 weeks.
• Insulin is effective and safe for the fetus, as it does not cross the placenta. Basal Bolus insulin therapy is more preferred but in the setting of resource limited area, premixed insulin twice regime is more comfortable for patients.
• Metformin was associated with a lower risk of neonatal hypoglycemia and less maternal weight gain than insulin. However, metformin readily crosses the placenta, resulting in umbilical cord blood levels of metformin as high or higher than simultaneous maternal level.
• Maximal dose for metformin is 1.5-2 g
• Metformin should not be used in pregnant people with hypertension or preeclampsia or those at risk for intrauterine growth restriction.

Self-monitoring of blood glucose

• Premeal, 1 hr post meal, 2 hr post meal, bed time (for pre-existing diabetes)

Intrapartum management

• Delivery is recommended between 37⁺⁰ weeks and 38⁺⁶ weeks of pregnancy.
• Monitor capillary plasma glucose hourly during labour
• Target: 70-126 mg/dl (4 and 7 mmol/litre)
• Intravenous dextrose and insulin infusion should be considered for women with type 1 diabetes from the onset of established labour and women with type 2 diabetes whose capillary plasma glucose is not maintained between 70-126 mg/dl (4 and 7 mmol/litre)
• VRIII regime with 10 % DW infusion (100ml/hour) is more advisable than GKI regime but need to stop just after delivery not to give rise to hypoglycemia.

Postpartum management

• • Encourage breast feeding.
  • Women with insulin-treated pre-existing diabetes should reduce their insulin immediately after birth and monitor their blood glucose levels carefully to establish the appropriate dose.
  • Women with pre-existing type 2 diabetes who are breastfeeding can resume or continue to take metformin.
  • Women with GDM should discontinue all glucose-lowering medications following delivery.
  • Screen at 12 weeks postpartum using 75g-OGTT and clinically appropriate non pregnancy criteria.
  • Individuals with a history of GDM should have lifelong screening for the type 2 diabetes or prediabetes every 1–3 years.
  • Offer lifestyle advice (including weight control, diet and exercise).
  • Preconception counselling and care should be continued for as long as they have childbearing potential (family planning and effective contraception).

In the departmental observational study done at YGH GDM clinic. Total 171 women with GDM were recruited and all of them received OGTT at 4-12 weeks postpartum. Among 171 GDM women, 118 patients (69%) had normal glucose tolerance and 36 patients (21%) had prediabetes and 17 patients (10%) had turned out to be type 2 diabetes at 4 to 12 weeks postpartum⁶.

Conclusion

Women who have a history of gestational diabetes mellitus (GDM) are at high risk of developing T2DM later in life. The American Diabetes Association recommends screening women with GDM for the persistence of diabetes at 4- 12 weeks postpartum via an oral glucose tolerance test (OGTT) and performing subsequent lifelong screening tests at least every 3 years using the clinically appropriate diagnostic criteria for non-pregnant women.

Care of diabetes in pregnancy (GDM or Pre-existing DM) is utmost important to prevent maternal and fetal complications, hence it is crucial to follow the clinical practice guideline in the management of diabetes in pregnancy as well as to expand the knowledge for primary health care workers (doctors, nurses, midwives). Last not but the least, it is essential to raise the awareness of prevention of diabetes among pregnant ladies.

References

1. American Diabetes Association. Management of Diabetes in Pregnancy. Standard of care in Diabetes-2024. Diabetes Care 2024. 42 (Suppl. 1): S282- S294.
2. International Diabetes Federation. IDF Diabetes Atlas 2021. 10^th edition. https://diabetesatlas.org
3. Latt TS, Aye TT, Aung MW, Ko K. 2013. “Summary of the Clinical Practice Guidelines for Diabetes Mellitus in Pregnancy in Myanmar”. Journal of the ASEAN Federation of Endocrine Society (JAFES); vol. 28 No. 1
4. National Collaborating Centre for Women’s and Children’s Health. NICE Clinical Guideline 63. Diabetes in pregnancy: Management of diabetes and its complications from pre-conception to the postnatal period. United Kingdom: National Institute for Health and Clinical Excellence, 2008.
5. Sirimarco, M. P., Guerra, H. M., Lisboa, E.G., Vernini J. M., Cassetari, B. N., de Araujo Costa, R. A., Cunha Rudge, M. V., Rarahos Calderon., I. M. 2017. “Diagnostic protocol for gestational diabetes mellitus (GDM) (IADPSG/ADA, 2011): influence on the occurrence of GDM and mild gestational hyperglycemia (MGH) and on the perinatal outcomes”. Diabetol Metab Syndr; 9:2, 1- 7
6. 6.Aung MW, Pyone ZC, Luther D. 2020. “Post partum risk of type 2 Diabetes Mellitus In women with gestational diabetes attending to Yangon General Hospital”, Poster presentation. AOCE SICEM.

Author Information

Khin Myo Aung¹, Zar Chi Pyone², Moe Wint Aung³

1. Senior Consultant, Department of Endocrinology, Yangon General Hospital
2. Lecturer, Department of Endocrinology, University of Medicine 1, Yangon
3. Professor and Head of Department of Endocrinology, University of Medicine 1, Yangon