Managing Gestational Diabetes

Cynthia V. Brown, RN, MN, ANP, CDESoutheastern Endocrine & Diabetes

Managing Gestational Diabetes• The management of gestational

diabetes is necessary for a healthy baby and mom.

• Managing this disorder well is a….

Richard Shafer:Richard Shafer:

…CHALLENGE!!!

Definitions

Gestational DiabetesPre-gestational Diabetes

Gestational diabetes...

• May have its’ onset or be first recognized during pregnancy

• Diabetes may have previously existed but not diagnosed

Pre-gestational diabetes...

• May be present and undiagnosed

• Evolving

• Already present and under treatment

Why is this important?

• Pre-existing diabetes at conception can lead to congenital anomalies

• Gestational diabetes leads to macrosomia and premature delivery

Congenital Malformations

• Cardiovascular: transposition, vsd, asd, hypoplastic left ventricle, anomalies of the aorta

• CNS: anencephaly, encephalocele, meningomyelocele, microcephaly

Malformations...

• Skeletal: caudal regression, spina bifida

• GU: Potter syndrome, polycystic kidneys

• GI: tracheoesophageal fistula, bowel atresia, imperforate anus

First Trimester Miscarriages

0

5

10

15

20

25

30

35

40

<6.05 6.05-7.2 7.2-8.3 8.3-9.5 >9.5

HbgA1c

Per

cent

of

wom

en

Complications by Trimester• First

– Still births– Miscarriages– Congenital defects

• Second and Third– Hyperinsulinism– Macrosomia– Delayed lung development

Complications...

• Delivery– Injuries– RD– Pregnancy loss– Neonatal hypoglycemia

Hormonal Influences

Decreased glucose levels

• Due to passive diffusion to fetus

• Causes hypoglycemia, even in non-diabetic patients

• Greatly decreases insulin need in first trimester

Accelerated starvation...

• Due to glucose diffusion

• Leads to elevated ketone production

• Unsure if this hurts baby or not

• Use as guide for increased calories

Decreased maternal alanine• Gluconeogenic amino acid

• Results in further lowering of FBS

Counterregulatory hormones• Suppressed responses to hypoglycemia• Study found BS as low as 44 did not

elicit a response• Level at which glucose & GH released

5-10 mg/dl lower in pregnant women with Type 1 DM

• Hypoglycemia aggravated by lower intake due to AM sickness

Prolonged hyperglycemia

• Enhances transplacental delivery of glucose to fetus

• Resistance to insulin x 5-6 hours PC

• Resistance related to several anti-insulin hormones

• Results in hyperglycemia

Hormones affecting blood sugar• Insulin • Glucagon• Epinephrine• Steroids• Growth hormone• Progesterone• Human placental lactogen

Peak Times of Hormonal Activity• Hormone Onset Peak

Potency• Estradiol 32 d 26 wk 1• Prolactin36 d 10 wk 2• HCS 45 d 26 wk 3• Cortisol 50 d 26 wk 5• Progesterone65 d 32 wk 4

Risk Factors

• Over 25 years of age• Family history of Type 2 diabetes• Obesity• Prior unexplained miscarriages or

stillbirths• History GDM or baby >10 pounds• PCOS

Dietary Modifications

• Decrease carbohydrate content• Frequent small feedings• Small breakfast meals• Bedtime snacks• No > 10 hours overnight fast• NO JUICE• Adequate calorie intake

Blood Sugar Goals

• Fasting: < 90 mg/dl• Premeal: 60-90 mg/dl• One-hour post-prandial: <120

mg/dl• Two-hour post-prandial: <120

mg/dl• 2AM-6AM: 60-90 mg/dl

Estimated insulin needs

• Prepregnancy 0.6 U/kg• Weeks 2-16 0.7 U/kg• Weeks 16-26 0.8 U/kg• Weeks 26-36 0.9 U/kg• Weeks 36-40 1.0 U/kg• Postpartum <0.6 U/kg

When to Start Medications

• Allow 1 week of dietary changes• Continue with diet if BS in target• First week with 2 elevated sugars,

insulin starts• Frequent testing so as not to miss

elevation• Anticipate need increasing• Do not be afraid!

Medications

• Sulfonylureas:– Glyburide typically used– Anecdotal evidence – Not very effective– Unable to achieve higher insulin

levels for meals– No long-term studies for safety

Medications

• Insulin:– NPH:

• BID dosing• Can start only at HS if FBS elevated• Long history of safety• Inconsistent absorption

Medications

• Lantus:– 24 hour coverage– Sometimes hard to affect dawn rise

without nocturnal low BS– Does not rise to meet meal-time rise

of BS

Medications

• Insulin analogs:– Humalog, Novolog, Apidra– Very rapid acting– Very effective pre- and post prandial– Less risk of hypoglycemia

Medications

• Regular insulin:– Slower onset– Longer duration– May be necessary in those who do not

want to take as many injections

Insulin Dosing During Labor• Need decreases dramatically• BS must be perfect in 72 hours

prior to delivery• May not need insulin during labor• Type 1 needs only basal insulin

with PRN supplementation

Postpartum

• Continue periodic testing • Aim to lose weight• Glucose challenge @ 6 wk check• Breast-feeding lowers BS, leads to

hypoglycemia

Managing Gestational Diabetes

THANK YOU!

Cynthia V. Brown, RN, MN, ANP, CDE

Southeastern Endocrine & Diabetes