QuestionSBA
QuestionChoice
Her weight of 97kg places her at a BMI of over 35. Any woman with a BMI >30 should be screened for gestational diabetes with a glucose tolerance test at 22-28 weeks.
49967
a
Weight of 97kg
QuestionChoice
Previous macrosomia may prompt investigation for gestational diabetes, but not forceps delivery alone.
49971
e
Previous forceps delivery
QuestionChoice
A parent or sibling with diabetes would prompt investigation for gestational diabetes with a glucose tolerance test.
49970
d
Maternal grandmother with type 2 diabetes and breast cancer
QuestionChoice
Previous baby >4.5kg would prompt screening for gestational diabetes with a glucose tolerance test at 22-28 weeks.
49968
b
Previous baby >4kg
QuestionChoice
Women of South Asian, Black, Afro-Caribbean, and Middle-Eastern origin are at increased risk of gestational diabetes and are therefore offered screening at 22-28 weeks with a glucose tolerance test.
49969
c
Irish origin
QuestionComment
I might just be dumb but im a bit confused on this question... isnt india in south asia? can someone explain why the answer is the BMI one?
24744
QuestionComment
Both are correct it’s just quesmed having fun with us 
24770
User
subscriber
Acute Gas
User
subscriber
Malignant Nightshift
QuestionComment
I'm confused, three of the answers seem to fall within the OGTT at 22-28 weeks criteria according to the explanations!
25008
User
subscriber
Inpatient Syndrome
QuestionComment
>4 kg is a high risk factor
52146
User
subscriber
Neutrophillia
Concept
Chapter
# Summary

Gestational Diabetes Mellitus (GDM) is a condition of glucose intolerance that begins or is first detected during pregnancy, leading to insulin resistance. It affects approximately 5% of pregnancies and poses an increased risk of type 2 diabetes development. The condition is more prevalent among women from ethnic backgrounds with a high prevalence of type 2 diabetes, those with a previous history of GDM, and obese women. GDM may lead to complications such as macrosomia, shoulder dystocia, pre-term delivery, neonatal respiratory distress syndrome, and maternal hypertension, including perinatal complications. Management strategies typically involve a low glycemic index diet, regular physical activity, medication (metformin or insulin) based on specific glucose levels, and postpartum glucose testing to ensure resolution.


# Definition 

Gestational Diabetes Mellitus (GDM) is defined as glucose intolerance with fasting blood glucose levels equal to or above 5.6 mmol/L or 2-hour plasma glucose levels equal to or above 7.8 mmol/L on a 75g Oral Glucose Tolerance Test (OGTT).


# Epidemiology

Approximately 5% of pregnancies are affected by GDM. Women diagnosed with GDM have an increased risk of developing type 2 diabetes, with up to a 50% chance within 5-10 years postpartum.


# Risk Factors



- Ethnic backgrounds with a high prevalence of type 2 diabetes (e.g., Middle Eastern, South Asian, and Afro-Caribbean)
- Prior history of GDM
- Prior delivery of macrosomic babies (>4.5kg)
- History of stillbirth or perinatal death
- Maternal obesity (BMI>30)
- Diabetes in first-degree relatives


# Signs and Symptoms



GDM often presents with no noticeable symptoms. However, some women may experience:

- Polyuria
- Thirst
- Fatigue


# Differential Diagnosis


- Type 1 or Type 2 Diabetes Mellitus: Generally presents with symptoms outside of pregnancy, including potential weight loss
- Other forms of gestational hyperglycaemia: These can be identified through early pregnancy HbA1c testing

# Investigations


Diagnosis of GDM is based on a 75g OGTT:

- Fasting blood glucose level (fasting glucose ≥5.6 mmol/L)
- 2-hour plasma glucose level (2-hour glucose ≥7.8 mmol/L)

This can be remembered as 'diagnosis of GDM is as easy as 5678'

Additional tests may include:

- HbA1c: Helpful in distinguishing between gestational and pre-existing diabetes early in pregnancy
- Urinalysis: To check for glycosuria

# Foetal Complications

- Macrosomia (birthweight >4kg): Excess maternal glucose crossing the placenta and inducing increased fetal insulin production can lead to macrosomia, increasing the risk of shoulder dystocia, birth injuries, and emergency caesarean section
- Increased risk of sacral agenesis in the developing foetus
- Pre-term delivery: May cause neonatal respiratory distress syndrome
- Neonatal hypoglycaemia: High fetal insulin levels after delivery may lead to hypoglycaemia, which if severe, may result in seizures in the baby
- Long-term risk: Increased risk of the baby developing type 2 diabetes later in life

# Maternal Complications

- Increased risk of hypertension and pre-eclampsia
- Future risk: Increased risk of developing type 2 diabetes and GDM in subsequent pregnancies

# Management

Management of GDM depends on specific glucose levels:

- Lifestyle modifications, such as adopting a low glycemic index diet and regular physical activity, are the initial approach when fasting glucose levels are <7 mmol/L.
	- If blood glucose targets are not met with diet and exercise changes within 1 to 2 weeks, offer metformin.
- If fasting glucose levels are ≥7 mmol/L, insulin therapy with or without metformin is often the first-line treatment.
- Advise pregnant women with any form of diabetes to maintain their capillary plasma glucose below the following targets, if these are achievable without causing problematic hypoglycaemia:
	- Fasting: 5.3 mmol/litre
	- 1 hour after meals: 7.8 mmol/litre
	- 2 hours after meals: 6.4 mmol/litre
- Postpartum management includes glucose testing to ensure resolution of GDM and long-term follow-up due to the increased risk of future type 2 diabetes.


# NICE Guidelines

[NICE CKS on Gestational Diabetes](https://www.nice.org.uk/guidance/ng3)


657
2291
Gestational Diabetes
Topic
38
Obstetrics
10030
A 29-year-old parous woman attends for her 20-week scan. On examination, her blood pressure is 134/87. Her height is 165cm, and her weight is 97kg. She had a previous baby four years ago who was delivered via forceps delivery at 39+0 weeks gestation and weighed 4.2kg. She has no past medical history; however, her maternal grandmother has type 2 diabetes and breast cancer. Urinalysis is clear.

Which of the following features in her history would prompt glucose tolerance testing at 24 weeks?
a