Gestational Diabetes Mellitus

What is gestational diabetes mellitus (GDM)?

GDM is defined as any degree of glucose intolerance with onset or first recognition during pregnancy.

 

What is the frequency of GDM?

Approximately 7% of all pregnancies are complicated by GDM, but incidence of GDM is on the rise.

 

When should GDM be evaluated?

Risk assessment for GDM should be undertaken at the first prenatal visit. Women with clinical characteristics consistent with a high risk of GDM (marked obesity, personal history of GDM, glycosuria (presence of glucose in urine), or a strong family history of
diabetes) should undergo testing for diabetes as soon as feasible. In pregnant women not known to have diabetes, screen for GDM at 24–28 weeks of gestation, using an oral glucose tolerance test.

 

What is the initial management for GDM?

All women with GDM should receive nutritional counseling. Programs of moderate physical exercise have been shown to lower maternal glucose concentrations in women with GDM. Women without medical or obstetrical contraindications are encouraged to start or continue a program of moderate exercise as a part of treatment for GDM.

 

What are blood glucose targets in case of GDM?

Target maternal capillary glucose concentrations (tested by glucometer) in pregnant ladies with GDM are

Preprandial (pre-meal) ≤95 mg/dl and

either             1-h postmeal ≤140 mg/dl

or             2-h postmeal ≤120 mg/dl

 

What if diet and exercise fails to control blood glucose?

If dietary and lifestyle changes fail to bring down maternal blood glucose levels to above targets, insulin is recommended. Insulin is the agent that has most consistently been shown to reduce fetal morbidity due to GDM. It is also the safest drug that is available to reduce blood glucose in pregnancy. Human insulin should be preferred (in place of analogs) when insulin is prescribed, and self monitored blood glucose values at home should guide the doses and timing of the insulin regimen.

 

How can we know whether the fetus is having any damage from GDM?

Assessment for asymmetric fetal growth or large sized fetus by ultrasonography, particularly in early third trimester, may aid in identifying fetuses that can benefit from maternal insulin therapy

 

Can medicines be used for treatment of GDM?

Medicines like metformin and glibenclamide are approved for treatment of GDM in some countries. If you are advised these medicines have a detailed discussion with your doctor regarding its advantages and disadvantages relative to insulin.

 

Do I need to undergo cesarean delivery if I have GDM?

GDM is not of itself an indication for cesarean delivery or for delivery before 38 completed weeks of gestation. Prolongation of gestation past 38 weeks increases the risk of fetal macrosomia (large sized baby) without reducing cesarean rates, so that delivery
during the 38th week is recommended unless obstetric considerations dictate otherwise.

 

What are the risks to the newborn from GDM?

GDM of any severity increases the risk of fetal macrosomia. The presence of fasting hyperglycemia (>105 mg/dl) may be associated with an increase in the risk of intrauterine fetal death during the last 4–8 weeks of gestation. Other complications in the
neonate as a result of GDM can be hypoglycemia (low neonatal blood glucose), jaundice, polycythemia (increased RBC), hypocalcemia (low calcium) and respiratory distress.

 

When should I undergo my next check up for diabetes after delvery?

Screen women with GDM for persistent diabetes 6–12 weeks postpartum.

 

Can I breast feed my baby?

Breast-feeding, as always, should be  encouraged in women with GDM.

 

What are the problems I may have in future after GDM?

Women with GDM are at increased risk for the development of diabetes, usually type 2, after pregnancy. Obesity and other factors that promote insulin resistance (e.g. PCOS) appear to enhance the risk of type 2 diabetes after GDM. Women with a history
of GDM should have lifelong screening for the development of diabetes or prediabetes at least every 3 years.

 

What are the problems my baby can have in future?

Offspring of women with GDM are at increased risk of obesity, glucose intolerance, and diabetes in late adolescence and young adulthood.