Pregnancy Flashcards
What can material diabetes mellitus cause in the baby?
Macrosomia (birth weight>4kg)
Structural defects (CNS - spina bifida ; skeletal - caudal regression syndrome ; renal - ureteric duplication)
Intrauterine death
Polyhydramnios
How does maternal hyperglycaemia cause macronosmia?
Why is this important?
- Maternal hyperglycaemia passed onto foetus
- Causes foetal hyperinsulinaemia
- Insulin is growth factor so baby grows
Has delivery implications
What changes are made to diabetes medication in pregnancy?
Consider changing oral therapy to insulin
What changes are made to diabetes monitoring in pregnancy?
More regular eye checks (3 monthly rather than annually)
Stricter blood glucose targets
What changes are made to labour management in a patient with diabetes?
Ensure strict blood glucose control with IV insulin and IV dextrose
What is gestational diabetes?
Condition where women without previous diabetes develops hyperglycaemia in pregnancy
At what stage in pregnancy does gestational diabetes usually occur?
3rd trimester
What is the pathophysiology of gestational diabetes?
Insulin resistance (by pogesterone and hPL) is a physiological response in pregnancy (ensures sufficient glucose supply to growing foetus)
In predisposed women this progresses to gestational diabetes
How is gestational diabetes managed?
Metformin
Some patients may need insulin
What follow up tests are done for patients with gestational diabetes and why?
Fasting plasma glucose measurement
Women with gestational diabetes are at high risk of developing T2DM
If fasting plasma glucose measurement is above 7, patient has diabetes
What anti-thyroid drugs are used in pregnancy with pre-existing hyperthyroidism?
1st trimester - prophylthiouracil
2nd/3rd trimester - carbimazole
What blood test should be offered in the third trimester to patients with hyperthyroidism and why?
TRAb antibodies
TRAb antibodies can cross the placenta and cause transient neonatal thyrotoxicosis
What is the differential diagnosis for a pregnant women presenting with vomiting associated with sweating, tachycardia and weight loss?
Hyperemesis of pregnancy
Hyperthyroidism
What is the commonest cause of thyrotoxicosis in pregnancy?
Gestational hCG associated thyrotoxicosis
What is the pathophysiology of gestational hCG associated thyrotoxicosis?
Human chorionic gonadosrophin is produced by placenta after implantation
It has very similar structure to TSH and can mimic its effects causing hyperthyroidism
What is the management of gestational hCG associated thyrotoxicosis?
Usually only lasts 20 weeks
Treat if it persists beyond 20 weeks
What happens to the thyroid gland and TFTs in pregnancy? Why? How?
Thyroid enlarges Primary hyperthyroidism (high T4, low TSH)
Cope with the increased metabolic rate required in pregnancy
Human chorionic gonadotrophin has very similar structure to TSH and stimulates primary hyperthyroidism
What hormone has a very similar structure to TSH?
Human chorionic gonadotoprhin (hCG)
Identical a-chain, ß-chain is different
What is done to the levothyroxine dose in pregnancy? Why is this done?
Increase by 25µg (as soon as pregnancy suspected)
Thyroid needs to be overactive in pregnancy to meet metabolic needs. An underactive gland can’t cope.
What does untreated hypothyroidism in pregnancy risk?
Poor neurological development of the child (cretinism)
