Gestational diabetes — structured SAQ (15 marks)

(a) Interpretation and classification (3 marks)

One mark for the correct diagnosis, one for the specific value that makes it, one for excluding overt diabetes in pregnancy. ^[1]

• This is gestational diabetes. The fasting plasma glucose of 5.5 mmol/L reaches the ADIPS 2025 diagnostic threshold of 5.3 mmol/L or more.^[1]
• One abnormal value is sufficient. The one-hour value (threshold 10.6 mmol/L) and the two-hour value (threshold 9.0 mmol/L) are both below their cut-points and do not change the diagnosis.^[1]
• This is not overt diabetes in pregnancy, which requires fasting 7.0 mmol/L or more, two-hour 11.1 mmol/L or more, or HbA1c 6.5% (48 mmol/mol) or more.^[1]
• Bonus reasoning mark: under the superseded ADIPS 2014 and IADPSG criteria (5.1 / 10.0 / 8.5) she would also be diagnosed, but on two values rather than one — a useful sentence if you have time.^[1]

(b) Initial management and targets (4 marks)

One mark each for the multidisciplinary referral, the monitoring plan, the specific targets, and nutrition plus activity advice. ^[1][2]

• Same-week referral to a credentialled diabetes educator and a dietitian; check whether an interpreter is needed and that she can afford strips.^[1]
• Self-monitoring: glucose meter and strips, testing fasting plus one or two hours after each main meal, with a written record.^[2]
• Targets, stated as numbers: fasting 5.0 mmol/L or less; one hour after a meal 7.4 mmol/L or less; two hours after a meal 6.7 mmol/L or less.^[2]
• Medical nutrition therapy: carbohydrate distributed across three meals and two to three snacks, lower glycaemic index choices, portion control, adequate protein, and an individualised gestational weight-gain target given her BMI of 33 kg/m2.^[1]
• Physical activity: 30 minutes of moderate activity most days, including a walk after the meal that misbehaves.^[1]
• Written escalation plan and review in one to two weeks — not four.^[1]

(c) Pharmacological management (4 marks)

One mark per agent with dose and route, one mark for matching the agent to the fasting pattern, one mark for a stated limitation. Marks are lost for "start medication" without specifics. ^[3][4]

• Match the drug to the pattern. Her abnormality is isolated fasting hyperglycaemia, so bedtime basal insulin or metformin is correct and prandial insulin alone is not.^[3]
• Give her a choice with the numbers. In MiG, 76.6% of metformin-treated women would choose metformin again versus 27.2% of the insulin group, and the neonatal composite outcome was equivalent (32.0% versus 32.2%).^[3]

(d) Fetal surveillance and timing of birth (2 marks)

One mark for the surveillance plan, one for a defensible, reasoned timing. ^[7][5]

• Serial growth ultrasound with abdominal circumference, estimated fetal weight centile and amniotic fluid every 3 to 4 weeks from about 28 to 30 weeks. Accelerating abdominal circumference triggers escalation of treatment, not reassurance.^[5]
• Timing: if she remains diet-controlled with normal growth, aim for birth by around 40+6 weeks. If she requires metformin or insulin, plan birth at about 38 to 39 weeks. Bring it forward for suspected macrosomia, poor control or another comorbidity.^[7][5]
• State the evidence honestly: the Cochrane review of planned birth in gestational diabetes found too few randomised data to be definitive, so this is consensus-based and individualised.^[7]

(e) Postpartum plan (2 marks)

One mark for the maternal plan with the interval, one for the neonatal plan. ^[5][6]

• Mother: stop all gestational diabetes pharmacotherapy at birth; check maternal glucose before discharge; book a 75 g two-hour oral glucose tolerance test at 4 to 12 weeks postpartum, then screening every 1 to 3 years lifelong; counsel on the roughly tenfold relative risk of later type 2 diabetes and on recurrence in a future pregnancy.^[5][8]
• Baby: anticipate neonatal hypoglycaemia — around half of at-risk babies in a New Zealand cohort became hypoglycaemic. Feed early and frequently, monitor blood glucose to the local protocol, keep mother and baby together, and use buccal 40% dextrose gel rather than reflex nursery admission.^[6]
• Breastfeeding support, and contraception plus pre-pregnancy advice before discharge.^[1]