Woman 9 Weeks Pregnant with Lethargy and Weight Gain - Case
This pregnancy case comes from our Med-Challenger FM, part of Med-Challenger's library of board exam review and CME question banks.
For more free clinical knowledge review questions, subscribe to the Med-Challenger Medical Education Blog.
Try this case and test your knowledge of pregnancy complications.
Question:
Which of the following statements is true concerning hypothyroidism and pregnancy?
Answer Options:
It is diagnosed by measuring free T4.
In a healthy patient, thyroid-stimulating hormone (TSH) levels decrease in the first trimester and then return to normal in the second and third trimester.
In a healthy patient, thyroid binding globulin hormone (TBG) levels increase each trimester in pregnancy.
Short-term hypothyroidism has no effect on the fetus.
See the Answer:
The correct answer is:
In a healthy patient, thyroid-stimulating hormone (TSH) levels decrease in the first trimester and then return to normal in the second and third trimester.
Educational Objective:
Discuss the process of diagnosing hypothyroidism during pregnancy.
Key Point:
Thyroid stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) concentrations in pregnancy are different from those in non-pregnant adults and vary by trimester. Due to these physiologic variations, pregnancy- and trimester-specific reference intervals for TSH should be used.
Explanation:
Pregnancy normally alters several components of the normal thyroid panel:
- There is a physiological and transient reduction in TSH seen usually between 8 and 14 weeks of gestation. This is due to the thyroid stimulating effects of the physiological increase in hCG early in pregnancy. In around 20% of women, the TSH may even drop below the normal range. After 14 weeks, the TSH usually returns to normal.
- Due to the increased circulating estrogen levels, there is an increase in thyroid binding globulin (TBG) that begins during the first half of pregnancy and continues to term.
- The increase in TBG results in lower levels of free T3 and T4 which stimulates the hypothalamic-pituitary-thyroid axis, which…
- ...results in higher levels of total (not free) T3 and T4.
- In addition, the abundance of deiodinase enzymes found in the placenta result in an increase in the metabolism of T4 to T3.
This free T4 is an unreliable measure of thyroid status in pregnancy.
Even short-term hypothyroidism can pose a risk to this patient; therefore, she should receive appropriate treatment if her labs indicated hypothyroidism. Most labs will have their own, specific pregnancy-adjusted reference intervals. If such pregnancy-specific reference intervals are not available, then those published by various societies can be used.
The American Thyroid Association (ATA)
The American College of Obstetricians and Gynecologists (ACOG)
References:
Nader S. Thyroid Disease and Pregnancy. Book Chapter in Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice, 60, 1022-1037.e4
Alexander EK, Pearce EN, Brent GA, Brown RS, Chen H, Dosiou C, Grobman WA, Laurberg P, Lazarus JH, Mandel SJ, Peeters RP, Sullivan S. “2017 Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum.” Thyroid 2017, 27(3):315-389.
Vaidya B, Hubalewska-Dydejczyk A, Laurberg P, Negro R, Vermiglio F, Poppe K. Treatment and screening of hypothyroidism in pregnancy: results of a European survey. Eur J Endocrinol. 2012;166(1):49-54.
Want more patient case questions like this?
This case is a sample from the following Med-Challenger exam prep and continuing medical education package.Med-Challenger FM PRO Bundle
Everything in Family Medicine
2023 New Year Sale
Save 10% with code:
"NEWYEAR23"
including PRO bundles.
Some restrictions apply.
Enter code at checkout. SHOP NOW.
FM PRO VALUE BUNDLE - Everything family physicians need for knowledge excellence, ABFM & FMCLA exam review, annual MOC CKSA requirements, and specialty CME credits, over their entire career - for one great value price.
$2801 in value. You save over 28%.
Ideal use of your CME Budget!
$1999
Questions?
Call 1-800-676-0822 or sales@chall.com
Current Customers:
If you already own any of the titles in FM PRO, contact us for special discounts and upgrade pricing.
FM PRO bundle includes:
One year of initial access free.
Includes ongoing MOC materials & requirements.
Includes one year of Premium Membership
Board review courses are pass-guaranteed.
Course Assets:
CME Credit Totals:
- 755 AMA PRA Category 1 CME Credits
- 248 AAFP Prescribed CME Credits
Gary Wilson, MDFM PRO is the ideal medical education purchase for family physicians. Useful every year and cost-effective.
2023 New Year Sale
Save 10% with code:
"NEWYEAR23"
including PRO bundles.
Some restrictions apply.
Enter code at checkout. SHOP NOW.
More from Med-Challenger
The Leader in Online Board Review, CME Courses, and Medical EducationDid you like this?
Get more free medical Q&A and informative CME articles.
Subscribe to the Medical Education Blog
More from Med-Challenger's Medical Education Blog
Acute Pregnancy Complications – Acute Medical / Surgical Complications in Pregnancy, Free CME Quiz – Earn AMA and ANCC Credits Free
February 1, 2023Woman 9 Weeks Pregnant with Lethargy and Weight Gain – Clinical Patient Case of the Week
January 31, 2023Woman with Diabetes, Eye Pain, Headache, and Vomiting – Clinical Patient Case of the Week
January 13, 2023Board Review & CME Offers
Med-Challenger provides online medical education, top-rated board review courses, annual MOC and CME credit solutions for physicians, nurses, PAs and students. Take advantage of our current offers.
2023 New Year Sale
Save 10% with code:
"NEWYEAR23"
including PRO bundles.
Some restrictions apply.
Enter code at checkout. SHOP NOW.
PRO
Career Value BundlesEVERYTHING
in your specialty.
One-time purchase.
Useful every year.
Ideal use your CME budget.
Buy or upgrade ONCE.
Save up to 55% and save time, money, and stress - every year.