CASE STUDIES
Gestational Diabetes Mellitus
1

Case study #1: Mrs. C
Mrs. C is a 22 year old primigravida coming for her first
antenatal checkup at 12 weeks of gestation.
On examination, she is 152 cm tall and weighs 69 kg.
BMI, 30 kg/m2
She does not have a family history of diabetes.
•Does she need to be screened for diabetes?
•If so, when?
•What screening test is to be used?
2

Mrs. C.
Mrs. C had a fasting blood glucose done
Her results are as follows.
•Does she have diabetes?
•Does she have GDM?
•Does she need to be tested again?
•If so, when?
Time 0 hr (Fasting)
Glucose
mmol/L(mg/dL)
4.7 (86)
3

Mrs. C
Mrs. C undergoes repeat testing at 26 weeks’ gestation.
Her results on the 75 gm glucose load (fasting) are as
follows.
•Does she have GDM?
•If yes, what treatment is indicated?
•When will you review her and using what tests?
Time 0 hr (Fasting) 1 hour 2 hour
Glucose
mmol/L(mg/dL)
4.8 (88) 10.3 (186) 8.9 (161)
4

Mrs. C
After 2 weeks, her results were as follows
•Is her glycemic control adequate?
•What is the next line of treatment?
•What other test can help assess level of glycemic control?
Fasting blood glucose mmol/L
(mg/dL
5.2 (93)
2 hour postprandial blood
glucose mmolL (mg/dL)
breakfast
8.6 (156)
5

Mrs. C
Mrs. C is put on 4 units of rapid acting insulin before
breakfast and advised to monitor her blood glucose daily.
She does well.
After 2 weeks, her reports are as follows.
•Is her glycemic control adequate?
•What is the next line of treatment?
Fasting blood glucose mmol/L (mg/dl) 6.5 (118)
2 hour postprandial blood glucose
mmol/L(mg/dl) breakfast
7 (126)
6

Mrs. C
Mrs. C is now on 6 units of NPH insulin at bedtime in
addition to 4 units of rapid acting insulin before breakfast.
She starts complaining of excess hunger during the early
hours of the morning.
Her reports are as follows.
•Are these values acceptable?
•What is the next line of treatment?
mmol/L (mg/dL)
Fasting BG 3.3 (61)
2 hour postprandial BG 5.6 (102)
7

Mrs. C
Her insulin dose has stabilized
 NPH 8 units at bedtime
 rapid acting insulin 6 u before breakfast, 4 units before lunch
and 4 units before evening meal.
Mrs. C goes into labour at 39 weeks.
Should she have been induced earlier?
Should a C-Section be considered?
How should her insulin be managed during labour
and delivery?
8

Mrs. C
Following delivery, blood glucose levels normalised and
she was able to stop insulin.
After 6 weeks, she underwent an OGTT, the results of
which are as follows.
•What is the diagnosis?
•What is her risk of developing diabetes in the future?
•When should she be tested next?
Time 0 hour (Fasting) 2 hours
Glucose mmol/L
(mg/dl)
4.5 (82) 7.0 (127)
9

Case study #2: Mrs. S
Mrs. S is a 35 year old nulliparous lady and has suffered
two miscarriages in the last three years.
After the last miscarriage she was diagnosed with PCOS
and has been on metformin since.
She did not test her blood glucose levels during either of
her previous pregnancies.
Her mother has diabetes.
She presents at 12 weeks gestation
What else do you need to know?
10

Mrs. S
• Does she need to be screened for diabetes?
• If so, when?
• What screening test is to be used?
• Should the metformin be continued?
• What is the purpose of metformin?
11

Mrs. S
Mrs S has an OGTT at 13 weeks gestation
Are these results ok?
Should she be retested? When?
What management strategies should be
considered?
Fasting 2 hour
Glucose
mmol/L(mg/dl)
6.0 (108) 9.0 (162)
12

Case Study #3: Mrs M
Mrs. M, 30/F – Primigravida
LMP: 13/10/12 EDC : 28/07/13 Regular cycles
Spontaneous conception 10 months after marriage
No family history of DM
13

Mrs M
Fasting BG at 6 weeks
Fasting
8.8 mmol/L (160 mg/dL)
What would you advise now?
Trial of MNT or medications right away?
Any other tests?
What risks to the pregnancy will you discuss with this lady?
14

Mrs M
Normal scan at 12 weeks with a low risk of Downs
19- 20 week scan plus fetal echo was normal
When will you advise next scan?
Glucose results as in next slide. Patient not very
regular with SMBG and not following the meal
plan
15

MRS M – Blood glucose record
Gestational
age
FBS mmol/L
(mg/dL)
1 h PPBS
mmol/L(mg/dL)
A1c
%
Medication
15 5.9 (107) 6.9 (125) 8.1 Premix 70/30
18 - 0 - 18 +
Metformin
500 BD
18 7.1 (129) 10.1 (183) 7.2 22 - 0 - 22 +
Metformin BD
19 5.3 (97) 9.6 (173) 26 - 0 - 20 +
Metformin BD
5.8 (105) 8.7 (157) 6.5
16

Mrs M
29 week scan
Ask to comment
17

Mrs M
She comes in with c/o discomfort and
abdominal pain at 30 weeks
How will you manage her now?
Uterus is irritable with some tightening on and
off
18

Mrs M
Tocolytic – which drug and dose
Steroids – dose / concerns in GDM
19

Mrs M
Uterine contractions settle. UTI picked up and treated with
appropriate antibiotics
She is now 37 weeks
FBS 5.5mmol/L (100mg/dL) 1 hr PPBS 8.3 mmol/L (150
mg.dL) on
Regular (soluble) 26-10-14 + NPH 0-0-12
Comes in with decreased movements
What would your approach be?
20

Case Study #4
Mrs. C, a 32 year old primigravida
Reports for the first antenatal checkup.
She is obese with a body mass index of 35 kg/m2, both her parents
have diabetes.
Her OGTT results are as follows.
Her HbA1c is 9.2%.
• What type of diabetes does this patient have?
• What is the ideal line of treatment?
• What is the prognosis for the pregnancy and for future resolution of
diabetes?
Time 0 hr (Fasting) 1 hour 2 hour
Glucose
mmol/L(mg/dL)
10.6 (192) 16.0 (288) 14.6 (263)
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