Thyroid Diseases In Pregnancy Flashcards
Most reliable test of thyroid gland in pregnancy
Free thyroxine
Tsh is produced from
Anterior pituitary
What is spillover syndrome
Hcg have the same alpha subunits as TSH-> so it mimics action pf tsh in pregnancy -> stimulate increase in thyroxine
Cause of worsen iodine deficiency in pregnancy
Due to:
- inc. GFR
- inc. uptake of iodine
- inc. trans placental tranfer
Hyperthyroidism TFT
Low TSH
High throxine
Complications of poorly controlled hyperthyroidism in pregnancy
Maternal
- thyroid storm
- CHF
- PE
Fetal
- FGR
- prematurity
- stillbirth
Signs of thyrotoxicosis in women
- failure to gain weight despite of good appetite
- tachycardia >100/min fails to slow despite of valsalva manoeavre
Mode of action propthiouracil and carbimazole
- Block thyroid hormone synthesis
- Immunosuppressive effect-> reducing TSH receptors stimulating ABs (TSHR-AB: the hallmark of Graves’ disease)
Sure sign of propylthiouracil and carbimazol
Agranulocytosis
(Severe neutropenia) that leads to sore throat
Do CBC
Management of hyperthyroidism in pregnancy
1st trimester: propylthiouracil
2nd,3rd: Carbimazol
Postpartum: propylthiouracil
Can we do thyroid surgery in pregancy
If needed
Indications of thyroid surgery in pregnancy
- Compression from a large goitre
- Suspicion of malignancy
- Failed antithyroid therapy
Do we give radioactive iodine in pregnancy ☢️
No it can crosses placenta and destroys the fetal thyroid
When to stop lactation before radioactive iodine
4 weeks before ttt
When to get pregnant after radioactive iodine
At least 6 months
If the male partner is taking radioactive iodine when to conceive
At least 4 months
Signs of thyrotoxicosis in neonates
- Tachycardia
- Excessive movements
- FGR, oligohydramnios & goitre
Fetal graves disease can cause premature delivery that accompanied by
Craniosynostosis
Hydrops fetalis
IUFD
polyhydramnios
Obstructed labor from neck extension related to goitre
HEG effect on TFTs
Transient hyperthyroidism
Suppressed TSH, high FT4
Over 60% of pregnancy
Iodine deficiency effect on neonate
Neonatal cretinism is leading preventable cause of mental handicap 2-10%
Normal TSH levels
0.5-4.5
Precoception TSH taget level for optimum fertility
<2.5
Hypothyroidism effect on menstruation
- Oligomenorrhea
- Menorrhagia
- Amneorreah
In some cases anovulation
Heavy less frequent menses
Hyperthyroidism effect on menstruation
- Polymenorrhea
- Hypomenorrhea
Light frequent menstruation
Subclincial hypothyroidism TFT
High TSH
Low FT3,FT4
Do OHSS will lead to thyroid disease
Increase E2 leads to inc TBG-> temporary hypothyroidism
Most common cause of hypothyroidism in women of reproductive age
Autoimmune thyroid disease AITD
Conplications of AITD
- Lower fertilization rate
- Poor embryo quality
- Precursor to overt thyroid dis
When to reassess thyroid levels after levothyroxine ttt
After 6 weeks of ttt
Do thyroid disease associated with miscarriage
Yes but yet routine screening in asymptomatic women is not recommended
Do levothyroxine decreases miscarriage in women with subclinical hypothyroidism
Yes
Most cause of hyperthyroidism in pregnancy
Graves’ disease
1%
How to diffrentiate between hyperthyroidism and gestational hyperthyroidism
Free T4 is generally raised, but TSH receptors antibodies are positive in graves
How Gestational hyperthyroidism treated
Only support ttt, as FT4 levels tend to return to normal in the 2nd trimester
Best antithyorioid in pregnancy
Propylthiouracil
But needs to be changed in 2nd trimester to prevent hepatotoxicity
Do AITD in euothyroid women is predictive of thyroid disease
Yes they have lymphocytic infiltration of the thyroid gland so may develop hypothyroidism in pregnancy
Do we give levothyroxine to euthyroid women with AITD
Not routinely recommended
Normal TSH levels with pregnancu
1st -2nd: 0.2 - 3 mU/l
3rd: 0.3-3 mU/l
LT4 dosage adjustment in pregnancy in women with hypothyroidism
Women with overt or subclinical hypothyroidism-> the dose must increase initially >25ug daily once pregnancy is confirmed
TFT every 4-6 weeks
Optimal level: 0.5-2.5 mU/l
Monitoring of fetuses and neonates of women with AITD
Fetal growth and heart rate for the rare risk of fetal hyperthyroidism
Neonatal review after delivery for the small risk of neonatal hyperthyroidism
TFTs assessment in euthyroid women with AITD
Every 4 weeks in early pregnancy
At least once bet 26-32 w
