OGCO-C1.2 Screening for gestational diabetes mellitus

Question 1

What is the genereal Mx for preexisting diabetes or GDM?

Answer 1

When not adequately controlled by diet alone.
Insulin when required is introduce in a basal plus regimen, guided by the blood sugar levels. Fasting hyperglycemia is usually treated with a basal insulin. Post meal hyperglycemia treated with meal time doses of a rapid acting analogue insulin used according to post meal blood glucose level relevant to each meal

Question 2

How to make a dx of DM in pregnancy and GDM?

Answer 2

Question 3

What are the indications for early OGTT screening?
When is early OGTT done?

Answer 3

• Early OGTT done between booking and 16 weeks of gestation

Indications for early OGTT
* Multiple pregnancy
* Previous babies >4kg
* Family history
* Maternal obesity
* PCOS
* Maternal age >35 years
* Previous unexplained stillbirth
* Abnormal babies not related to known chromosomal or genetic abnormalities

Women who have preexisting IGT and are on diet control only should undergo early OGTT and be managed according to the early OGTT result.
Those who are screened negative should proceed with a routine OGTT.

Question 4

What women dont require OGTT?

Answer 4

Known diabetics who are pregnant or planning pregnancy should be referred to QMH CEC. The high risk Obs team can also be consulted for direct admission of pregnant diabetic women requiring changing from oral hypoglycemiac agents to insulin as in patients.

Question 5

What is the aim of HBSM?

Answer 5

• Pre-meal blood glucose levels: 3.8 - 6.0mmol/L
• 2-hour post-meal blood glucose levels: 4.0 – 6.9mmol/L

Question 6

What are the baseline Ix for those with elevated fasting blood glucose >7mmol/L or those initiating insulin therapy?

Answer 6

o Ultrasound scan for fetal growth
o CBC, LRFT
o Urine culture
o Fundi examination

Question 7

How to manage patients with unsatisfactory glycemic control?

Answer 7

• Readjust diet
• Start insulin therapy if necessary or add Metformin if indicated (to be discussed with endocrinologist)
• After consultation with senior staff, blood test for HbA1c (8-weekly), fructosamine (4-
  weekly), +/- urine culture, spot urine for microalbumin and protein:creatinine ratio and
  fundi examination may be arranged
• Ultrasound scan should be repeated for assessment of fetal growth

Question 8

When is home blood sugar monitoring (HBSM) done?
What are the target values?

Answer 8

Pre and post meal
Pre meal: should be <6, post meal = <7

HBS< x 6 if FG <6, x3 if FG <6 for 2 days in 1 week. Check for dietary compliance if exceeds limit (advise patient to adhere to diet). As long as patient is not persistently exceeding values, patient con continue dietary control instead of medical insulin Mx.