Term
| What anatomical changes occur in the (maternal) thyroid gland during pregnancy? |
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Definition
| Glandular hyperplasia, thyroid enlargement, but without change in the echostructure. |
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Term
| How does the dietary demand for iodine change in pregnancy? |
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Definition
| Due to increased clearance by the kidneys, more iodine than normal is necessary. |
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Term
| How does estrogen affect T4 & T3 levels? |
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Definition
| Estrogen increases production of thyroxine-binding globulin (TBG) and decreases its clearance. The resultant rise in TBG levels leads to an increase in T3 and T4. |
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Term
| What is the prevalence of thyrotoxicosis in pregnancy? |
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Definition
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Term
| What is the most common cause of thyrotoxicosis in pregnancy? |
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Definition
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Term
| How may Graves' disease affect the fetus? |
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Definition
| Thyroid-stimulating antibodies (TSAb) may cross the placenta when their titer is high (the placenta acts as a partial barrier), causing fetal or neonatal hyperthyroidism. |
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Term
| What are the signs and symptoms of hyperthyroidism? Which of these are most specific in pregnancy? |
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Definition
Heat intolerance, fatigue, anxiety, diaphoresis, tachycardia, widened pulse pressure - all these can be found in normal pregnancy.
Signs specific to hyperthyroidism: pulse >100, goiter and exophthalmus. |
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Term
| What are the lab findings in hyperthyroidism? |
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Definition
Elevated T3, T4
Low TSH
Possible:
Normocytic normochromic anemia
Mild neutropenia
Elevated liver enzymes |
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Term
| What is the clinical significance of subclinical hyperthyroidism? How common is it? |
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Definition
| None. No screening or treatment needed. Occurs in 5% of women of reproductive age, 2.5% of pregnancies. |
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Term
| What is the most common complication from hyperthyroidism in pregnancy? |
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Definition
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Term
| What are the complications of poorly controlled hyperthyroidism in pregnancy? |
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Definition
| Increased risk of miscarriage, preterm labor, SGA fetuses (IUGR), placental abruption. Maternal: anemia, higher risk of infections, cardiac arrhythmias, CHF, thyroid storm. |
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Term
| How common is thyroid storm? How does this present? |
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Definition
Thyroid storm occurs in 8% of women with thyrotoxicosis.
Classic presentation: thermoregulatory dysfunction, CNS effects (agitation, delirium, coma), GI dysfunction, tachycardia, heart failure (reversible). |
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Term
| What is the treatment of thyrotoxicosis in pregnancy? (Drug classes, duration, setting) |
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Definition
Medical. Surgery is reserved for extreme cases.
Thioamides (PTU or methimazole) - women taking small doses (PTU<100, methimazole<10) can stop at 32-34wks, unless symptoms recur, large goiter, long-standing hyperthyroidism or significant eye involvement.
Beta-blockers for symptomatic control (only for a few weeks, <34-36wks, may cause IUGR or hypoglycemia).
Treatment is on an outpatient basis unless severe case in 3rd trimester. |
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Term
| What are the differences between PTU and methimazole? |
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Definition
Mechanism of effect: similar, though PTU also inhibits peripheral conversion of T4 to T3.
Initial dosing: PTU = 200-400mg/d, methimazole = 20-40 mg/d.
Length of action: shorter in PTU (more frequent dosing).
SEs: similar. PTU may cause irreversible liver damage. |
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Term
| What are the side effects of anti-thyroid medication? |
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Definition
Neonatal hypothyroidism.
Maternal: pruritis, rash, urticaria, fever, arthralgias, cholestatic jaundice, lupus-like syndrome, migratory polyarthritis.
Leukopenia - take CBC before Tx, may be caused by disease or drug.
Agranulocytosis - 0.1%. |
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Term
| What is the treatment of thyroid storm? |
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Definition
| Treat aggressively: PTU or mehtimazole, iodine solution (SSKI or Lugol), beta-blockers, steroids. |
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Term
| Is breastfeeding contraindicated under antithyroid treatment? |
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Definition
| Only if doses exceed 150mg/d (PTU), 10mg/d (methimazole). |
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Term
| What percentage of women with hyperemesis gravidarum present with biochemical hyperthyroidism? |
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Definition
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Term
| What is the prevalence of hypothyroidism in pregnancy? |
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Definition
Overt - 1.8:1000
Subclinical - 23:1000
Total - 2.5% |
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Term
| What is the most common cause of hypothyroidism in pregnancy? |
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Definition
| Hashimoto's thyroiditis - prevalence of 8-10% in women of reproductive age. |
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Term
| What are the effects of hypothyroidism on pregnancy? |
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Definition
| Thyroid antibodies may cross the placenta, causing neonatal hypothyroidism. Lower IQ in infant. Increased risk of preeclampsia, abrupto placentae, prematurity, IUFD. |
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Term
| What is the treatment of hypothyroidism in pregnancy? |
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Definition
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Term
| What is congenital hypothyroidism? How common is it? |
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Definition
| Defined as hypothyroidism in the neonate. 1:4000-7000 births. |
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Term
| What are the common causes of congenital hypothyroidism? |
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Definition
| Most common - thyroid dysgenesis. 15% genetic (enzyme defects). Transient hypothyroidism may be caused by maternal anti-thyroid therapy or iodine deficiency. |
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Term
| How is congenital hypothyroidism treated? |
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Definition
| Oral thyroid supplementation, usually with T4. |
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Term
| How common is postpartum thyroiditis? |
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Definition
| Common: 5-10% in first post-partum year. |
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Term
| Which 2 groups of women are especially at risk for postpartum thyroiditis? |
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Definition
| Women with high titers of anti-thyroid Abs, women with type 1 DM. |
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Term
| What are the 2 clinical phases of postpartum thyroiditis? |
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Definition
First phase: 1-4m, destruction-induced thyrotoxicosis, abrupt onset, goiter.
Second phase: 4-8m. 2/3 will become euthyroid, 1/3 will become hypothyroid. |
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Term
| How is postpartum thyroiditis treated? |
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Definition
| Symptomatically: beta-blokcers for phase I, low-dose levothyroxine or T3 for phase II. T4 supplementation may be helpful. |
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Term
| What percentage of women with postpartum thyroiditis will remain hypothyroid? |
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Definition
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Term
| How should a solitary thyroid nodule be managed in pregnancy? |
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Definition
FNA. If benign - ignore. If malignant - consider surgery (risks lowest in 2nd trimester), or defer to post-partum (thyroid cancer is usually indolent).
Radionuclide scans or ablation are absolutely contraindicated in pregnancy. |
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Term
| How common is hyperparathyroidism in pregnancy? |
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Definition
| Rare - 0.8%. Less common in pregnancy than usual. |
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Term
| How do PTH levels change during pregnancy? |
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Definition
| Unchanged in first half, rise steadily in second. |
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Term
| What are the common causes of hyperparathyroidism in pregnancy? |
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Definition
| 90% - adenoma, 9% hyperplasia, 1% malignancy. |
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Term
| What are the 3 fetal/neonatal complications of hyperparathyroidism? |
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Definition
Fetal death - 27.5%
Neonatal tetany - 19%
Neonatal hypoclacemia - days 2-14 after birth, resolves with therapy. |
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Term
| What are the 6 maternal complications of hyperparathyroidism? |
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Definition
1. Nephrolithiasis - 39%
2. Bone disease - 19%
3. UTI (and pyelonephritis) - 13%
4. Pancreatitis - 13% (compared to 1.5% nonpregnancy hyperparathyroid patients; <0.5% of euparathyroid pregnancies). May be fatal.
5. Hypertension - 10% (100% in carcinoma)
6. Hypercalcemic crisis - 8%. May be fatal. |
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Term
| What percentage of pregnant women with hyperparathyroidism are symptomatic? |
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Definition
| 76%, whereas 50-80% of nonpregnant patients are asymptomatic. |
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Term
| How should hyperparathyroidism in pregnancy be treated? |
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Definition
Surgically (preferably in the 2nd trimester).
If surgery is not possible, instate diuresis with saline and furosemide (give potassium and magnesium). Consider oral phosphates. |
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Term
| What are the signs of hypoparathyroidism? |
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Definition
| Dry, scaly skin, brittle nails, coarse hair, Chvostek sign (10%), Trousseau sign. Ectopic soft tissue calcification, prolonged QT. |
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Term
| Why is Cushing's syndrome uncommon in pregnancy? |
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Definition
| 75-80% of women with Cushing's have menstrual irregularities or are infertile. |
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Term
| What is the differential diagnosis of Cushing's syndrome? |
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Definition
1. Cushing's disease - most common
2. Ectopic ACTH secretion
3. Cortisol secreting adrenal adenoma (or carcinoma) - 25% |
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Term
| How can Cushing's syndrome be diagnosed in pregnancy? |
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Definition
1. Loss of diurnal variation of cortisol (or ACTH).
2. Free urinary cortisol of >250 mg/24hrs
3. Lack of dexamethasone suppression of cortisol |
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Term
| What are the 3 common fetal complications of Cushing's syndrome? |
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Definition
1. Preterm labor - 63%
2. IUGR - 26-37%
3. Fetal losses (abortion or stillbirth) - 16% |
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Term
| What two common gestational diseases are much more common in women with Cushing's disease? |
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Definition
Hypertension - 70%
Diabetes - 32% |
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Term
| What is the maternal mortality from Cushing's sydnrome? |
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Definition
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Term
| How should a pregnancy complicated by Cushing's syndrome be managed? |
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Definition
| Early delivery in 3rd trimester (as soon as fetus is mature) with postponement of definitive treatment of the mother. |
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Term
| What is the most common cause of CAH (congenital adrenal hyperplasia)? |
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Definition
| 21-hydroxylase deficiency (90-95%) |
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Term
| How is a fetus with CAH affected? |
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Definition
| Increased ACTH leads to adrenal hyperplasia, excess androgens cause masculinization of the external genitalia, and fetus has Addison's syndrome. |
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Term
| How is pheochromocytoma diagnosed? |
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Definition
| Excess levels of free cathecholamines, metanephrine (>1.2mg) or vanillymandelic acid in 24hr urine sample. Total cathecholamines >2000pg/mL in serum. Locate tumor by MRI. |
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Term
| What is the maternal and fetal mortality in pheochromocytoma in pregnancy? How should it be managed? |
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Definition
| Maternal mortality = 48%, fetal = 55%. Control BP with phenoxybenzamine (+- beta blockers), surgery in 2nd trimester or when fetus is mature. Vaginal delivery is CI. |
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Term
| What is the most common pituitary tumor encountered in pregnancy? |
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Definition
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Term
| What is the treatment of prolactinomas? |
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Definition
| If tumor enlarges: medical therapy (bromocriptine or cabergoline) with daily visual field exams. 2nd line - steroids. 3rd line - surgery. |
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Term
| What is the risk of growth during pregnancy of a prolactinoma? How should these be followed? |
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Definition
Microadenoma (<10mm) - risk is 1-2%. Routine MRI not recommended.
Macroadenoma (>=10mm) - 15-25% (4% if previously treated). Monthly visual field examinations and MRI if growth suspected.
In case of severe headache or visual changes - perform MRI. |
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Term
| How should labor and puerperium be managed in women with prolactinomas? |
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Definition
| Shorten 2nd stage in women with tumor growth to avoid increased ICP. F/U w/ MRI 3-4m post-partum. |
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Term
| Does blood loss and/or hypotension always precede Sheehan's syndrome? |
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Definition
| No. 10% of women have no history of bleeding or hypotension. |
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Term
| What is the full-blown presentation of Sheehan's syndrome? How soon does it appear? |
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Definition
| Persistent hypotension, tachycardia, hypoglycemia and failure to lactate. Full-blown picture may take even years to appear. |
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Term
| What is the prevalence of diabeted insipidus (DI) in pregnancy? How is DI affected by pregnancy? |
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Definition
1:50000-80000.
A transient form of DI in pregnancy exists (maybe due to vasopressinase production by the placenta).
60% of patients with DI worsen in pregnancy, 20% improve and 20% are unchanged. |
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