How does calcium increase in newborn postnatally?
Increase in PTH
What are classic causes of neonatal hypocalcemia?
Gestational diabetes and preeclampsia
Mothers have PTH dysfunction that doesn’t affect mothers but does affect babies
Maternal thyroid hormone is critical in which trimester?
First trimester development
Which is most common cause of congenital hypothyroidism?
Dysgenesis 85%
Most sensitive and specific test of hypothyroidism ?
TSH
Dopamine infusion can lead to transient _______ in TSH
Decrease
Good measure of thyroid function?
Free T4
Only free form can enter the cell
What is Pendred Syndrome?
What is the association with hypothyroidism?
Deafness (CN 8)
Goiter
Hypothyroidism
AR
Cause of permament primary hypothyroidism
Iodide organification defect
Management of neonatal DI
Thiazide diuretics > DDAVP (neonatal dosing is difficult)
Thiazides work by decreasing distal tubular reabsorption of sodium via inhibition of sodium-chloride cotransported resulting in natriuresis and volume contraction which results in increased water and Na reabsorption in distal tubule and collecting duct.
Adding free water to formula may lead to FTT and not recommended
Which thyroid hormone transfers freely across the placenta?
Thyroyropin releasing hormone
Also TSH receptor stimulating and blocking antibodies
T3 and T4 are partially permeable
Most common cause of virilization of genetic female neonate is?
CAH
The optimal postnatal age to determine baseline thyroid function in newborn?
24 hrs
How does hydrocort help with BP?
Inhibits catecholamine metabolism, blocking reuptake of circulating catecholamines-> increasing BP
2dary effect: upregulates cardiovascular adrenergic receptors
Where is calcium stored in the body?
When and how is is transferred during pregnancy?
Skeletal system contains
99% of whole body calcium
85% phosphorus
65% magnesium
3rd Trimester - 80% of Ca+ and phosphorus are transferred by active transport across the placenta (*regardless of maternal status)
Aside from glucose and insulin, what compound(s) contribute to the development of macrosomia in IDM babies?
Insulin like growth factor 1
Insulin like growth factor binding protein 3
Term neonate
hyponatremic hyperkalemic crisis
Aldosterone and cortisol deficiency
Increased testosterone
What is most likely gene mutation causing this enzyme defect ?
CYP21
Mutation of 21 hydroxylase gene CYP21 is MCC of CAH in North America
How do you treat a symptomatic baby with congenital hyperthyroidism from maternal Graves’ disease
Preferred first agent- Methimazole
PTU- no longer preferred due to liver failure risk
Beta-blocker- hemodynamic instability; inhibits peripheral conversion T4 to T3
Iodinde: inhibitis thyroid hormone release/synthesis
When does the fetal thyroid gland begin secreting thyroid hormone?
12 weeks
In the 1st trimester, testosterone production from the Leydig cells is driven by _______
Placental human chorionic gonadotropin (HCG)- before 8 weeks
_________ increases in the 2nd trimester and stimulates phallic enlargement and testicular descent.
Fetal pituitary luteinizing hormone
Thyroid gland develops from
Median endodermal thickening in primitive pharyngeal floor at 5-7 weeks gestation
What GA does TRH production, thyroglobulin, TSH and thyroid hormone start?
TRH and thyroglobulin from hypothalamus at 8 weeks
Iodide starts accumulating at 10 weeks
TSH by pituitary gland and thyroid hormones~12 weeks
What medication can cause transient decrease in TSH?
Dopamine
What is the preferred drug for treating maternal hyperthyroidism?
Why not methimazole?
PTU- Assoc’d with face and neck cysts
Methimazole- associated with cutis aplasia
