GESTATIONAL DIABETES

WHAT IS GESTATIONAL DIABETES? Is a condition in which women without

previously diagnosed diabetes exhibit high blood glucose levels during pregnancy.

"Gestational" diabetes implies that this

disorder is induced by pregnancy, perhaps due to exaggerated physiological changes in glucose metabolism

DEFINITION

Gestational diabetes is formally defined as "any degree of glucose intolerance with onset or first recognition during pregnancy".

This definition acknowledges the possibility that patients may have previously undiagnosed diabetes mellitus, or may have developed diabetes coincidentally with pregnancy. Whether or not symptoms subside after pregnancy is also irrelevant to the diagnosis

GESTATIONAL DIABETES – diabetes diagnosed during pregnancyUndiagnosed PDM – during first half of

pregnancyGDM – during the late part of gestation

OVERT DIABETES – patients known to have diabetes even before pregnancy

What causes this?

No specific cause has been identified, but it is believed that the hormones produced during pregnancy reduce a woman's sensitivity to insulin, resulting in high blood sugar levels.

PATHOPHYSIOLOGY

Almost all women have some degree of impaired glucose intolerance during pregnancy as a result of hormonal changes that occur during pregnancy. That means that their blood sugar may be higher than normal, but not high enough to have diabetes. During the later part of pregnancy (the third trimester), these hormonal changes place pregnant woman at risk for gestational diabetes.

During pregnancy, increased levels of certain hormones made in the placenta (the organ that connects the baby by the umbilical cord to the uterus) help shift nutrients from the mother to the developing fetus. Other hormones are produced by the placenta to help prevent the mother from developing low blood sugar. They work by stopping the actions of insulin.

Over the course of the pregnancy, these hormones lead to progressive impaired glucose intolerance (higher blood glucose levels). To try to decrease the glucose levels, the body makes more insulin to shuttle glucose into cells.

Usually the mother's pancreas is able to produce more insulin (about three times the normal amount) to overcome the effect of the pregnancy hormones on glucose levels. If, however, the pancreas cannot produce enough insulin to overcome the effect of the increased hormones during pregnancy, glucose levels will rise, resulting in gestational diabetes.

PATHOPHYSIOLOGY

EPIDEMIOLOGY

Gestational diabetes affects 3-10% of pregnancies, depending on the population studied

It occurs in between 5 and 10% of all pregnancies (between 1-14% in various studies).

RISK FACTORS

A previous diagnosis of gestational diabetes or prediabetes, impaired glucose tolerance, or impaired fasting glycaemia

A family history revealing a first degree relative with type 2 diabetes

Maternal age - a woman's risk factor increases the older she is (especially if older than 35 years of age)

Ethnic background (those with higher risk factors include African-Americans, North American native peoples and Hispanics)

Being overweight, obese or severely obese increases the risk by a factor 2.1, 3.6 and 8.6, respectively.

Previous pregnancy which resulted in a child with a high birth weight (>90th centile, or >4000 g)

Previous poor obstetric history

SIGNS AND SYMPTOMS Frequently women with gestational

diabetes exhibit no symptoms However, possible symptoms include

increased thirst, increased urination, fatigue, nausea and vomiting, bladder infection, yeast infections and blurred vision.

DIAGNOSIS

PregestationalDM (DM prior to pregnancy)Diagnosis:

FBS > 126 mg/dl on 2 occasions or RBS > 200 mg/dl or 75 gm 2 hour OGIT > 200 mg/dl

. Gestational DMA. Screening test (at 24-28 weeks usually or

earlier): 50 gm 1 hour Oral Glucose Challenge of > 140 mg/dl or 7.8mmol/L

b. If (+) screening test do Gold Standard For Gestational DM Diagnosis: 100 gm 3 hour Oral Glucose Tolerance test (OGTT) after an overnight fast of 8-14 hours

DIAGNOSIS

TIMING OFMEASUREMENT

Plasma Glucose mg/dL

National Diabetes Group (1979)

Plasma Glucose mg/dL

Carpenter and Coustan (1982)

Fasting 105 95

1 hour 190 180

2 hour 165 155

3 hour 145 140

If two values are above normal then the patient is + Gestational DM. 

MATERNALCOMPLICATIONS

Increased risk for Cesarean Delivery Higher risk of Preeclampsia Diabetic ketoacidosis Coronary Artery Disease Nephropathy Retinopathy

FETAL COMPLICATIONS

Large for gestational age (macrosomic) Macrosomia in turn increases the risk of

instrumental deliveries (e.g. forceps, ventouse and caesarean section)

Problems during vaginal delivery (such as shoulder dystocia).

Neonates are also at an increased risk of low blood glucose (hypoglycemia), jaundice, high red blood cell mass (polycythemia) and low blood calcium (hypocalcemia) and magnesium (hypomagnesemia).

Potential Congenital Fetal Anomalies

1.CNS: spina bifida, anencephaly, holoprosencephaly, hydrocephalus

2.Cardiac (most common): transposition of the great vessels, ventricular septal defect, atrial septal defect, hypoplastic left heart, cardiac hypertrophy, anomalies of the aorta

3.GI: tracheoesophageal fistula, anal/rectal atresia

4.Genitourinary: renal agenesis, double ureter, cystic kidneys

5.Skeletal: caudal regression syndrome (most specific)

6.Situs inversus

GDM also interferes with maturation, causing dysmature babies prone to respiratory distress syndrome due to incomplete lung maturation

PROGNOSIS

Gestational diabetes generally resolves once the baby is born.

Based on different studies, the chances of developing GDM in a second pregnancy are between 30 and 84%, depending on ethnic background.

A second pregnancy within 1 year of the previous pregnancy has a high rate of recurrence

WHITE CLASSIFICATION

Named after Priscilla White who pioneered in research on the effect of diabetes types on perinatal outcome, is widely used to assess maternal and fetal risk.

It distinguishes between gestational diabetes (type A) and diabetes that existed prior to pregnancy (pregestational diabetes).

Emphasizes that end organ derangements, especially involving the eyes, kidneys, have significant effects on pregnancy outcomes

CLASS ONSET FASTING PLASMA GLUCOSE

2 HOUR POST PRANDIAL GLUCOSE

THERAPY

A1 Gestational <105mg/dl <120mg/dl Diet

A2 Gestational >105mg/dl >120mg/dl Insulin

CLASS AGE OF ONSET

DURATION (YEARS)

VASCUALR DISEASE

THERAPY

B Over 20 <10 None Insulin

C 10 – 19 10 – 19 None Insulin

D Before 10 >20 BenignRetinopathy

Insulin

F Any Any Nephropathy Insulin

R Any Any Proliferativenephropathy

Insulin

H Any Any Heart insulin

MANAGEMENT

GENERAL The patient with GDM is at higher risk of

developing glucose intolerance later in life. Approximately 40% of women with GDM

develop DM within 15 years. GDM may be an early manifestation of DM

type 2 that is temporarily unmasked by the diabetogenic hormones of pregnancy.

Women with GDM are commonly treated on an outpatient basis.

The primary focus for women with GDM is dietary control of glucose intake and adequate monitoring of glucose values.

GDM is divided into two categories: A1 (glucose control by diet alone) and A2 (glucose control with diet and insulin). If glucose levels cannot be controlled with diet

alone, then insulin therapy should be started.

DIET

Diabetic Diet To provide the

necessary nutrients for the mother and the fetus

To control glucose levels

To prevent starvation ketosis

RECOMMENDED DAILY CALORIC INTAKE AND PREGNANCY WEIGHT GAIN IN WOMEN WITH GESTATION DMCURRENT

WEIGHT IN RELATION TO IDEAL BODY WEIGHT

DAILY CALORIC INTAKE (Kcal/Kg)

RECOMMENDED PREGNANCY WEIGHT GAIN (LBS)

<80-90% 36-40 28-40

80-120% (ideal) 30 25-35

120-150% 24 15-25

>150% 12-18 15-25

DIABETIC DIET Ideal Body Weight = [(Height in inches X

2.54) - 100] - 10% (if female) Ideal Body Weight X 35 cal/Kg = Total

calories/day

SAMPLE DIET

Total calories = 1800-2400 cal/day 60% Carbohydrate: Total cal/day X 0.60 =

1200 cal /4 = 300gm carbo 20% Protein: Total cal/day X 0.20 = 400

cal / 4 = 100 gm protein 20% Fat: Total cal/day X 0.20 = 400 cal / 9

= 45 gm fat

PRECONCEPTUAL AND PREGNANCY WORKUP The patient should have a preconceptual history and

physical examination, an ophthalmologic examination, and measurement of an ECG..

The patient should be advised to maintain tight glucose level control.

Measurement of HbA1C may be helpful in evaluating glucose control and assessing risk of fetal malformations.

HbA1C levels of 10% or higher are associated with significant risk of fetal malformations. If the HbA1C level is within the normal range, risk appears to be similar to that of nondiabetic women.

A 24-hour urine measurement of creatinine clearance and protein excretion should also be performed for evaluation of kidney function.

The patient should be started on folate 400 µg/day for spina bifida prophylaxis.

The patient should be encouraged to maintain an appropriate activity level or exercise program.

FETAL MONITORING

FIRST TRIMESTER minimal fetal monitoring is required (i.e.,

assessment for heart tones by Doppler ultrasonography at each visit during the latter portion of the first trimester).

SECOND TRIMESTER Measurement of maternal serum alpha-

fetoprotein levels, along with levels of unconjugated estriol and human chorionic gonadotropin, represents the triple screen, which is typically performed at 16–18 weeks' gestation.

Ultrasonography (usually at 18–20 weeks) helps to date the pregnancy and evaluate the fetus for genetic abnormalities and other congenital anomalies that may be present.

Fetal cardiac anomalies are the most common congenital anomalies with PDM, and so a fetal echocardiogram is recommended at 19–22 weeks' gestation.

THIRD TRIMESTER Regular fetal surveillance should be initiated for

all pregnancies in insulin-requiring diabetic women.

Fetal surveillance should be performed frequently in the presence of maternal vascular disease, hypertension, ketoacidosis, pyelonephritis, preeclampsia, and poor patient compliance.

In well-controlled DM without associated complications of hypertension and vascular disease, minimal ongoing evaluation of the fetus may be required.

In poorly controlled or complicated DM, the incidence of fetal compromise and death is much higher, and therefore frequent fetal evaluation is required.

Repeat obstetrical ultrasonographic examinations for fetal growth may be considered at 28–30 weeks and then at 36–38 weeks.

If the patient has evidence of microvascular disease, monthly ultrasonographic examinationS starting at 24–26 weeks may be necessary to closely follow fetal growth to assess for intrauterine growth restriction (IUGR).

Tests commonly used for fetal assessment are the nonstress test, biophysical profile, and contraction stress test.

MEDICAL TREATMENT

INSULIN TREATMENT

Do not give oral hypoglycemic agents. These are contraindicated during pregnancy

Sample Insulin Regimen: i.Humulin N (intermediate) or Humulin U

(Ultralente - long acting ) OD in a.m. ii.Humulin N & R combination (intermediate &

short acting) at 6 a.m. and 6 p.m.

(2/3 of daily dosage to be given at 6 AM and 1/3 of daily dosage at 6 p.m.)

Note: Aim for normal blood glucose

(FBS =105 and Two-hour postprandial blood glucose of < 140 mg/dl.

Insulin requirements increase throughout gestation, from approximately

0.7 U/kg (body weight)/day during weeks 6–18, to

0.8 U/kg/day during weeks 18–26, to 0.9 U/kg/day during weeks 26–36, and to 1.0 U/kg/day during weeks 36–40.

GOALS FOR GLUCOSE CONTROL

Fasting: 60–90 mg/dL Premeal: less than 100 mg/dL 1 hour postprandial: less than 140 mg/dL 2 hours postprandial: less thAn 120 mg/dL Bedtime: less than 120 mg/dL 2–6 am: 60–90 mg/dL

TREATMENT

Control diabetes at first 6 weeks AOG to prevent birth defects

Deliver baby ideally at 36-37 weeks AOG

POSTPARTUM EVALUATION In the postpartum period, a woman with GDM

(A1 and A2) should have a follow-up GTT at 6–12 weeks postpartum to assess for possible PDM.

The recommended test to further evaluate for overt DM is as follows: a fasting blood glucose value is taken, then a 75-g oral glucose load is administered, then a 2-hour glucose level is measured. If the threshold values are met or exceeded in follow-

up testing, the patient should then be followed and treated for overt DM.

TIME SINCE 75g GLUCOSE

LOAD

NO DM IMPAIRED GLUCOSE

TOLERANCE

OVERT DM

FASTING < 110 mg/dl 110 – 125 mg/dl

> OR EQUAL TO 125 mg/dl

2 HOUR < 140 mg/dl 140 – 199 mg/dl

> OR EQUAL TO 200 mg/dl

Patient should be placed back on an ADA diet (with increased soluble fiber and reduced fat).

She should do a lifestyle assessment and attempt to keep her weight near ideal for her height.

Weight reduction is generally necessary, and thus, if the patient is not breastfeeding, calories are reduced to 1200–1500 kcal with repeat dietary instruction, and the same calorie ADA diet is continued as the patient is breastfeeding.

The caloric demand of breastfeeding increases with neonatal size but can reach 800–1200 kcal per day.

Exercise equivalent to expend the energy is to run hard for 1 hour (900 kcal). It takes 3500 kcal expended to reduce weight by 1 pound! She should enter a regular exercise program.

THANK YOU!!!