Sub-classifications of GDM

There are two sub-classifications of gestational diabetes mellitus. Class A 1 is able to maintain glycemic control by following a meal plan and not using any medications. Class A 2 requires a specialized meal plan as well as insulin or oral agents in order to maintain glycemic control.

 

Fetal Monitoring

Fetal monitoring is done through a series of tests, alone or in various combinations, and maybegin as early as 28 weeks. Let’s take a minute and go over these tests.

The non-stress test, or NST, measures the acceleration of the fetal heart rate in response to fetal activity. A Doppler ultrasound is used. A non-reactive test result is an indication for more fetal monitoring.

A biophysical profile is a combination of ultrasound with the NST. It measures fetal heart rate, breathing, body movement, muscle tone, and amniotic fluid volume.

An ultrasound measurement of fetal abdominal circumference, along with self-monitoring of blood glucose provides useful information to help guide management decisions. If the infant’s abdomen is <75 percentile for gestational age the physician may consider less intensive management (meaning less SMBG monitoring). If the abdominal girth is excessive, the physician may choose to intensify treatment by lowering blood glucose targets or adding medications or insulin.

Additionally, the ADA recommends that mothers with gestational diabetes should be taught how to monitor fetal movement during the last 8-10 weeks of pregnancy.

Amniocentesis is used to monitor for genetic or chromosomal disorders.

And the Contraction Stress Test measures fetal heart rate in response to uterine contractions. To induce mild contractions either a low dose of oxycotin is administered or the mother’s nipples are stimulated. A negative test result is associated with good fetal outcomes.

 

Maternal Monitoring: Blood Glucose Testing

BG is checked 4 times daily fasting & 1 hr or 2 hrs after meals TIME mg/dl Before breakfast < 96 mg/dl 1 hour after meals < 140 mg/dl 2 hours after meals < 120  mg/dl

 

Observational studies suggest that when average glucose levels are maintained at < 87 mg/dL, there is an increased likelihood of the infant being small for their gestational age (or SGA).

The presence of ketones may indicate an inadequate intake of energy or carbohydrates. Research has suggested that ketones in the blood may decrease an infant’s intelligence.

 

Ketone testing is recommended for patients with:    Severe hyperglycemia       Weight loss during treatment       Concerns about possible “starvation ketosis”

The usefulness of HA1c testing in women with gestational diabetes is unclear. It may be useful if gestational diabetes is diagnosed before 20 weeks gestation.

 

         at each prenatal visit to detect the development of preeclampsia.

Pregnant women with gestational diabetes are at an increased risk for hypertension, so routine testing of blood pressure and urinary protein is recommended at each prenatal visit.

Also the frequency of spontaneous preterm birth may be increased in women with untreated gestational diabetes. When indicated, corticosteroids may be used to enhance fetal lung maturity.