Presenter Disclosures NO CONFLICTS OF INTEREST Thyroid Disease in - - PowerPoint PPT Presentation

June 15th, 2019

Thyroid Disease in Pregnancy: Hot or Cold?

Amy M. Valent, DO

Assistant Professor Department of Obstetrics & Gynecology, Division of Maternal-Fetal Medicine

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Presenter Disclosures

NO CONFLICTS OF INTEREST

Objectives

• 1. Review relevant maternal and fetal physiology

that influence thyroid function

• 2. Discuss the importance of maternal thyroid

function and production during pregnancy

• 3. Review diagnosis considerations and

treatments for thyroid disease in pregnancy

Not discussing: thyroid cancer, nodules, thyroid storm, postpartum thyroiditis

TG stored

Glinoer D. J Clin Endocrinol Metab 79(1):197-204 (modified)

TSH Receptor

Requires thyroid peroxidae T4 T3

What are the 2 main driving factors that increase thyroid hormone?

• A. Progesterone & Estrogen
• B. Estrogen & hCG

C. plasma volume & hCG D. GFR &  plasma volume

How much does iodine clearance increase during pregnancy? A.10-20% B.30-50% C.50-70% D.80%

Iodine

• Pregnancy & lactation 220-

290mcg/day

• 150 mcg/day through PNV

(kelp? KI?)

• Whole food sources:

seafood, eggs, meat, and poultry

• Iodinized salt
• Disparities

Zimmerman Paediatric and Perinatal Epidemiology.2012; 26: 108-117 Cochrane Database of Systematic Reviews 2017, Issue 3. Art.No:CD011761 WHO, IOM, AAP, American Thyroid Association, Endocrine Society, Teratology Society

 T4 production  Renal excretion  T4 fetal transfer  Iodine fetal transfer

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Burrow et al. NEJM. 1994 Oct 20;331(16):1072-8. Soldin et al. Thyroid. 2004 Dec;14(12):1084-90.

Relative Changes in Thyroid Function

Pregnancy Physiology

 Thryoid hormone production

 HCG  Thyroxine binding globulin  Plasma volume  Fetal transfer Placental deiodinases

Hypothyroidism

• Pregnancy loss
• Preterm birth
• Preeclampsia
• Placenta abruption
• Low birth weight
• IUFD
• Lower child IQ

Haddlow JE. N Engl J Med. 1999;341(8):549-555. Abalovich M. Thyroid. 2002;12(1):63-68.

• Lazarus. N Engl J Med. 2012 Feb 9;366(6):493-50
• Casey. N Engl J Med. 2017 Mar 2;376(9):815-825.
• Maraka. BMJ. 2017; 356: i6865.

Hyperthyroidism

• Pregnancy loss
• Preeclampsia
• Placental abruption
• CHF/Thyroid storm
• Indicated preterm birth
• Low birth weight /FGR
• Fetal or central hypothyroidism
• *Fetal thyrotoxicosis
• *Neonatal hyperthyroidism

*Specifically with Grave’s

Who should be screened?

ATA (2017) Endo Society (2012) ACOG (2017) SMFM (2014) Universal screening No Yes/No No No “High risk” screening Yes Yes Yes Yes Screening lab TSH TSH TSH TSH TPO Ab Yes

(TSH>2.5mU/L)

• Negro. J Clin Endocrinol Metab . 91(7):2587–2591 Obstet Gynecol. 2015 Apr;125(4):996-1005. JCEM. 2012; 97 (8): 2543–2565

(ATA Guidelines) Thyroid. 2017 Mar;27(3):315-389. SMFM. Contemporary OB/GYN 2012; 45-47.

Who is considered “high risk”?

• Signs/symptoms or history of thyroid dysfunction
• Goiter or +thyroid antibodies
• Type 1 DM or other autoimmune disorders
• >30 years of age
• Morbid obesity (BMI ≥40)
• History of miscarriage, infertility or preterm birth
• ≥2 prior pregnancies
• History of head/neck radiation or thyroid surgery
• Family history of thyroid disease
• Taking amiodarone or lithium
• Residing in a moderate/severe iodine insufficient area

Maternal hypothyroidism

“Maternal hypothyroidism is defined as a TSH concentration elevated beyond the upper limit of the pregnancy-specific reference range.” Who works with a laboratory that has determined the population-pregnancy-specific reference range? What should the targets be? 2.5mIU/L & 3.0mIU/L? 4.0mIU/L?

(ATA Guidelines) Thyroid. 2017 Mar;27(3):315-389.

Diagnosis & who should we treat?

? ? ? ? ? ? ↑ TSH ↔ TSH ↑ TSH ↑↑ TSH ↔TSH TSH ↓TT4* ↓ TT4* ↔ TT4* ↔TT4* ↔TT4* TT4*

Stagnaro-Green A et al. Thyroid. 2011 Oct;21(10):1081-125

• Casey. N Engl J Med. 2017 Mar 2; 376(9): 815–825.
• Lazarus. N Engl J Med. 2012 Feb 9;366(6):493-501

(ATA Guidelines) Thyroid. 2017 Mar;27(3):315-389.

Hypo HTX Yes No SC Yes/No Hypo Yes HG/SC No Hyper Yes…

*FT4 can be checked with caution

Hypothyroid Management

Diagnosis Treatment Prepregnancy hypothyroidism 2 additional tablets per week Newly diagnosed hypothyroidism TSH <4 1.2mcg/kg/day TSH 4-10 1.5mcg/kg/day TSH >10 2-2.5mcg/kg/day Subclinical Hypo (ART or +TPO Ab) Goal TSH <2.5mIU/L +TPO Ab, Euthyroid TSH q4 wks +TPO Ab, Euthyroid, h/o Loss TSH q4 wks vs 25-50mcg/day

Yassa L. J Clin Endocrinol Metab, July 2010, 95(7):3234–3241 Alexander EK. N Engl J Med 2004;351:241-9. Hollowell JG. JCEM 2002:2: 489–499 Dhillon-Smith N Engl J Med 2019;380:1316-25.

How is hypothyroidism best treated?

• A. Dessicated thyroid
• B. Methimazole

C.Levothyroxine D.Liothyronine

Iodide, lithium, thioamides Glucocorticoid dopamine somatostatin Glucocorticoids, ipodate sodium, propranolol, PTU, amiodarone

Competing Drugs

FeSO4, sucralfate,

cholestyramine

Al(OH)3 Phenytoin, rifampin, phenobarbital, sertraline, carbamazepine

Which one does not cross placenta?

A.Iodine B.Thionamides C.TSH D.Corticosteroids

• E. Dopamine antagonists/agonists
• F. Antibodies (TSI, TRAb, TPO, TG)

G.T4

Hyperthyroid management

1st Trimester

MMI/ PTU vs

• ff

HG = supportive SC Hyper = none

2nd Trimester

18-22 wks

Ab check 3rd Trimester

US findings

Polyhydramnios goiter, tachycardia, bone hypodensity

Active surveillance FT4/TT4 every 2-4 weeks

MMI 10-30 mg daily PTU 50–300 mg daily

(ATA Guidelines) Thyroid. 2017 Mar;27(3):315-389.

Take home points

• Thyroid hormone has significant implications in

pregnancy and the long-term neurologic health in

• ffspring
• Too much thyroid is bad
• Too little thyroid is bad
• Subclinical (slightly low) thyroid is…
• Thyroid replacement is only as good as you take it

(empty stomach with large glass of water for 1 hr)

• Anti-thyroid medications lowest supportive dose
• Be mindful of who you screen particularly in the first

TM

Thank You

Amy Valent valent@ohsu.edu cell: 503-502-7220