Pregnancy And Thyroid Disease
Pregnancy andThyroid DiseaseNational Endocrine and Metabolic Diseases Information ServiceWhat is thyroid disease?U.S. Departmentof Health andHuman ServicesNATIONALINSTITUTESOF HEALTHThyroid disease is a disorder that affects thethyroid gland. Sometimes the body producestoo much or too little thyroid hormone.Thyroid hormones regulate metabolism—theway the body uses energy—and affect nearlyevery organ in the body. Too much thyroidhormone is called hyperthyroidism and cancause many of the body’s functions to speedup. Too little thyroid hormone is calledhypothyroidism and can cause many of thebody’s functions to slow down.PituitaryglandTSHThyroid hormone plays a critical role during pregnancy both in the development of ahealthy baby and in maintaining the health ofthe mother.Women with thyroid problems can have ahealthy pregnancy and protect their fetuses’health by learning about pregnancy’s effecton the thyroid, keeping current on their thyroid function testing, and taking the requiredmedications.ThyroidT3-T4The thyroid’s production of thyroid hormones—T3and T4—is regulated by TSH, which is made by thepituitary gland.
What is the thyroid?The thyroid is a 2-inch-long, butterfly-shapedgland weighing less than 1 ounce. Locatedin the front of the neck below the larynx, orvoice box, it has two lobes, one on either sideof the windpipe. The thyroid is one of theglands that make up the endocrine system.The glands of the endocrine system produce,store, and release hormones into the bloodstream. The hormones then travel throughthe body and direct the activity of the body’scells.The thyroid gland makes two thyroid hormones, triiodothyronine (T3) and thyroxine(T4). T3 is the active hormone and is madefrom T4. Thyroid hormones affect metabolism, brain development, breathing, heartand nervous system functions, body temperature, muscle strength, skin dryness, menstrual cycles, weight, and cholesterol levels.Thyroid hormone production is regulated bythyroid-stimulating hormone (TSH), whichis made by the pituitary gland in the brain.When thyroid hormone levels in the bloodare low, the pituitary releases more TSH.When thyroid hormone levels are high,the pituitary responds by decreasing TSHproduction.2 Pregnancy and Thyroid DiseaseHow does pregnancynormally affect thyroidfunction?Two pregnancy-related hormones—humanchorionic gonadotropin (hCG) andestrogen—cause increased thyroid hormonelevels in the blood. Made by the placenta,hCG is similar to TSH and mildly stimulatesthe thyroid to produce more thyroid hormone. Increased estrogen produces higherlevels of thyroid-binding globulin, also knownas thyroxine-binding globulin, a protein thattransports thyroid hormone in the blood.These normal hormonal changes can sometimes make thyroid function tests duringpregnancy difficult to interpret.Thyroid hormone is critical to normaldevelopment of the baby’s brain and nervoussystem. During the first trimester, the fetusdepends on the mother’s supply of thyroidhormone, which comes through the placenta.At around 12 weeks, the baby’s thyroidbegins to function on its own.The thyroid enlarges slightly in healthywomen during pregnancy, but not enough tobe detected by a physical exam. A noticeably enlarged thyroid can be a sign of thyroiddisease and should be evaluated. Thyroidproblems can be difficult to diagnose inpregnancy due to higher levels of thyroidhormone in the blood, increased thyroid size,fatigue, and other symptoms common toboth pregnancy and thyroid disorders.
HyperthyroidismWhat causes hyperthyroidism inpregnancy?Hyperthyroidism in pregnancy is usually caused by Graves’ disease and occursin about one of every 500 pregnancies.1Graves’ disease is an autoimmune disorder. Normally, the immune system protects people from infection by identifyingand destroying bacteria, viruses, and otherpotentially harmful foreign substances. Butin autoimmune diseases, the immune systemattacks the body’s own cells and organs.With Graves’ disease, the immune systemmakes an antibody called thyroid-stimulatingimmunoglobulin (TSI), sometimes calledTSH receptor antibody, which mimics TSHand causes the thyroid to make too muchthyroid hormone. In some people withGraves’ disease, this antibody is also associated with eye problems such as irritation,bulging, and puffiness.disappearance of signs and symptoms—ofGraves’ disease in later pregnancy may resultfrom the general suppression of the immunesystem that occurs during pregnancy. Thedisease usually worsens again in the firstfew months after delivery. Pregnant womenwith Graves’ disease should be monitoredmonthly.2More information about Graves’ diseaseis provided by the National Endocrine andMetabolic Diseases Information Service(NEMDIS) in the fact sheet, Graves’ Disease,available at www.endocrine.niddk.nih.gov.Rarely, hyperthyroidism in pregnancy iscaused by hyperemesis gravidarum—severenausea and vomiting that can lead to weightloss and dehydration. This extreme nauseaand vomiting is believed to be triggered byhigh levels of hCG, which can also lead totemporary hyperthyroidism that goes awayduring the second half of pregnancy.Although Graves’ disease may first appearduring pregnancy, a woman with preexisting Graves’ disease could actually seean improvement in her symptoms in hersecond and third trimesters. Remission—a1KomalPS, Mestman JH. Graves hyperthyroidismand pregnancy: a clinical update. Endocrine Practice.2010;16(1):118–129.3 Pregnancy and Thyroid Disease2Ogunyemi DA. Autoimmune thyroid disease andpregnancy. eMedicine website. . Updated April23, 2010. Accessed August 11, 2011.
How does hyperthyroidismaffect the mother and baby?Uncontrolled hyperthyroidism during pregnancy can lead to congestive heart failure preeclampsia—a dangerous rise inblood pressure in late pregnancy thyroid storm—a sudden, severe worsening of symptoms miscarriage premature birth low birth weightIf a woman has Graves’ disease or wastreated for Graves’ disease in the past withsurgery or radioactive iodine, the TSI antibodies can still be present in the blood, evenwhen thyroid levels are normal. The TSIantibodies she produces may travel acrossthe placenta to the baby’s bloodstream andstimulate the fetal thyroid. If the mother isbeing treated with antithyroid medications,hyperthyroidism in the baby is less likelybecause these medications also cross theplacenta.Women who have had surgery or radioactiveiodine treatment for Graves’ disease shouldinform their health care provider, so the babycan be monitored for thyroid-related problems later in the pregnancy.4 Pregnancy and Thyroid DiseaseHyperthyroidism in a newborn can result inrapid heart rate, which can lead to heart failure; early closure of the soft spot in the skull;poor weight gain; irritability; and sometimesan enlarged thyroid that can press againstthe windpipe and interfere with breathing.Women with Graves’ disease and their newborns should be closely monitored by theirhealth care team.How is hyperthyroidism inpregnancy diagnosed?Health care providers diagnose hyperthyroidism in pregnant women by reviewingsymptoms and doing blood tests to measureTSH, T3, and T4 levels.Some symptoms of hyperthyroidism are common features in normal pregnancies, including increased heart rate, heat intolerance,and fatigue.Other symptoms are more closely associatedwith hyperthyroidism: rapid and irregular heartbeat, a slight tremor, unexplainedweight loss or failure to have normal pregnancy weight gain, and the severe nauseaand vomiting associated with hyperemesisgravidarum.
A blood test involves drawing blood at ahealth care provider’s office or commercialfacility and sending the sample to a lab foranalysis. Diagnostic blood tests may include TSH test. If a pregnant woman’ssymptoms suggest hyperthyroidism,her doctor will probably first performthe ultrasensitive TSH test. This testdetects even tiny amounts of TSH in theblood and is the most accurate measureof thyroid activity available.Generally, below-normal levels of TSHindicate hyperthyroidism. However, lowTSH levels may also occur in a normalpregnancy, especially in the first trimester, due to the small increase in thyroidhormones from HCG. T3 and T4 test. If TSH levels are low,another blood test is performed to measure T3 and T4. Elevated levels of freeT4—the portion of thyroid hormone notattached to thyroid-binding protein—confirm the diagnosis.Rarely, in a woman with hyperthyroidism, free T4 levels can be normal butT3 levels are high. Because of normalpregnancy-related changes in thyroidfunction, test results must be interpreted with caution. TSI test. If a woman has Graves’ disease or has had surgery or radioactiveiodine treatment for the disease, herdoctor may also test her blood for thepresence of TSI antibodies.More information about testingfor thyroid problems is providedby the NEMDIS in the fact sheet,Thyroid Function Tests, available atwww.endocrine.niddk.nih.gov.5 Pregnancy and Thyroid DiseaseHow is hyperthyroidism treatedduring pregnancy?During pregnancy, mild hyperthyroidism, inwhich TSH is low but free T4 is normal, doesnot require treatment. More severe hyperthyroidism is treated with antithyroid medications, which act by interfering with thyroidhormone production.Radioactive iodine treatment is not anoption for pregnant women because it candamage the fetal thyroid gland. Rarely,surgery to remove all or part of the thyroidgland is considered for women who cannottolerate antithyroid medications.Antithyroid medications cross the placenta insmall amounts and can decrease fetal thyroidhormone production, so the lowest possibledose should be used to avoid hypothyroidismin the baby.Antithyroid medications can cause sideeffects in some people, including allergic reactions such as rashes anditching a decrease in the number of white bloodcells in the body, which can lower aperson’s resistance to infection liver failure, in rare cases
Stop your antithyroid medication andcall your health care provider right awayif you develop any of the following signsand symptoms while taking antithyroidmedications: fatigue weakness vague abdominal pain loss of appetite a skin rash or itching easy bruising yellowing of the skin or whites ofthe eyes, called jaundice persistent sore throat feverIn the United States, health care providers prescribe the antithyroid medicationmethimazole (Tapazole, Northyx) for mosttypes of hyperthyroidism.Experts agree that women in their firsttrimester of pregnancy should probably nottake methimazole due to the rare occurrenceof damage to the fetus. Another antithryroid medication, propylthiouracil (PTU), is6 Pregnancy and Thyroid Diseaseavailable for women in this stage of pregnancy or for women who are allergic to orintolerant of methimazole and have no othertreatment options.Health care providers may prescribe PTU forthe first trimester of pregnancy and switchto methimazole for the second and thirdtrimesters.Some women are able to stop antithyroidmedication therapy in the last 4 to 8 weeksof pregnancy due to the remission of hyperthyroidism that occurs during pregnancy.However, these women should continue tobe monitored for recurrence of thyroid problems following delivery.Studies have shown that mothers taking antithyroid medications may safely breastfeed.However, they should take only moderatedoses, less than 10 20 milligrams daily, ofthe antithyroid medication methimazole.Doses should be divided and taken afterfeedings, and the infants should be monitored for side effects.2Women requiring higher doses of the antithyroid medication to control hyperthyroidism should not breastfeed.
HypothyroidismWhat causes hypothyroidism inpregnancy?Hypothyroidism in pregnancy is usuallycaused by Hashimoto’s disease and occurs inthree to five out of every 1,000 pregnancies.2Hashimoto’s disease is a form of chronicinflammation of the thyroid gland.Like Graves’ disease, Hashimoto’s diseaseis an autoimmune disorder. In Hashimoto’sdisease, the immune system attacks the thyroid, causing inflammation and interferingwith its ability to produce thyroid hormones.Hypothyroidism in pregnancy can also resultfrom existing hypothyroidism that is inadequately treated or from prior destructionor removal of the thyroid as a treatment forhyperthyroidism.How does hypothyroidism affectthe mother and baby?Some of the same problems caused by hyperthyroidism can occur with hypothyroidism.Uncontrolled hypothyroidism during pregnancy can lead to preeclampsia anemia—too few red blood cells in thebody, which prevents the body from getting enough oxygen miscarriage low birth weight stillbirth congestive heart failure, rarely7 Pregnancy and Thyroid DiseaseBecause thyroid hormones are crucial tofetal brain and nervous system development,uncontrolled hypothyroidism—especiallyduring the first trimester—can affect thebaby’s growth and brain development.How is hypothyroidism inpregnancy diagnosed?Like hyperthyroidism, hypothyroidismis diagnosed through a careful review ofsymptoms and measurement of TSH and T4levels.Symptoms of hypothyroidism in pregnancyinclude extreme fatigue, cold intolerance,muscle cramps, constipation, and problemswith memory or concentration. High levelsof TSH and low levels of free T4 generallyindicate hypothyroidism. Because of normalpregnancy-related changes in thyroid function, test results must be interpreted withcaution.The TSH test can also identify subclinicalhypothyroidism—a mild form of hypothyroidism that has no apparent symptoms.Subclinical hypothyroidism occurs in 2 to3 percent of pregnancies.2 Test results willshow high levels of TSH and normal free T4.Experts differ in their opinions as to whetherasymptomatic pregnant women should beroutinely screened for hypothyroidism. Butif subclinical hypothyroidism is discoveredduring pregnancy, treatment is recommended to help ensure a healthy pregnancy.
How is hypothyroidism treatedduring pregnancy?Hypothyroidism is treated with syntheticthyroid hormone called thyroxine—a medication which is identical to the T4 madeby the thyroid. Women with preexistinghypothyroidism will need to increase theirprepregnancy dose of thyroxine to maintainnormal thyroid function. Thyroid functionshould be checked every 6 to 8 weeks duringpregnancy. Synthetic thyroxine is safe andnecessary for the well-being of the fetus ifthe mother has hypothyroidism.Eating, Diet, and NutritionDuring pregnancy, the body requires higheramounts of some nutrients to support thehealth of the mother and growing baby.Experts recommend pregnant women maintain a balanced diet and take a prenatal multivitamin and mineral supplement containingiodine to receive most nutrients necessary forthyroid health. More information about dietand nutrition during pregnancy is providedby the National Agricultural Library availableat tary SupplementsBecause the thyroid uses iodine to make thyroid hormone, iodine is an important mineralfor a mother during pregnancy. During pregnancy, the baby gets iodine from the mother’s diet. Women need more iodine whenthey are pregnant—about 250 micrograms aday. In the United States, about 7 percent ofpregnant women may not get enough iodinein their diet or through prenatal vitamins.3Choosing iodized salt—salt supplementedwith iodine—over plain salt and prenatalvitamins containing iodine will ensure thisneed is met.However, people with autoimmune thyroiddisease may be sensitive to harmful sideeffects from iodine. Taking iodine drops oreating foods containing large amounts ofiodine—such as seaweed, dulse, or kelp—may cause or worsen hyperthyroidism andhypothyroidism. More information aboutiodine is provided by the National Libraryof Medicine in the fact sheet, Iodine in diet,available at www.nlm.nih.gov/medlineplus.To help ensure coordinated and safe care,people should discuss their use of dietarysupplements with their health care provider. Tips for talking with health careproviders are available at the NationalCenter for Complementary and AlternativeMedicine’s Time to Talk campaign atwww.nccam.nih.gov.3Zimmerman MB. Iodine deficiency in pregnancyand the effects of maternal iodine supplementation onthe offspring: a review. American Journal of ClinicalNutrition. 2009;89(2):668S–672S.8 Pregnancy and Thyroid Disease
Postpartum ThyroiditisWhat is postpartum thyroiditis?Postpartum thyroiditis is an inflammation ofthe thyroid that affects about 4 to 10 percentof women during the first year after givingbirth.2 Thyroiditis causes stored thyroidhormone to leak out of the inflamed thyroidgland and raise hormone levels in the blood.Postpartum thyroiditis is believed to bean autoimmune condition and causesmild hyperthyroidism that usually lasts1 to 2 months. Many women then develophypothyroidism lasting 6 to 12 months beforethe thyroid regains normal function. In somewomen, the thyroid is too damaged to regainnormal function and their hypothyroidismis permanent, requiring lifelong treatmentwith synthetic thyroid hormone. Postpartumthyroiditis is likely to recur with futurepregnancies.Postpartum thyroiditis often goes undiagnosed because the symptoms are mistakenfor postpartum blues—the exhaustion andmoodiness that sometimes follow delivery. Ifsymptoms of fatigue and lethargy do not goaway within a few months or a woman develops postpartum depression, she should talkwith her health care provider. If the hypothyroid symptoms are bothersome, thyroidmedication can be given.9 Pregnancy and Thyroid DiseasePoints to Remember Thyroid disease is a disorder thatresults when the thyroid gland produces more or less thyroid hormonethan the body needs. Pregnancy causes normal changes inthyroid function but can also lead tothyroid disease. Uncontrolled hyperthyroidism during pregnancy can lead to serioushealth problems in the mother andthe unborn baby. During pregnancy, mild hyperthyroidism does not require treatment.More severe hyperthyroidism istreated with antithyroid medications, which act by interfering withthyroid hormone production. Uncontrolled hypothyroidism during pregnancy can lead to serioushealth problems in the mother andcan affect the unborn baby’s growthand brain development. Hypothyroidism during pregnancyis treated with synthetic thyroidhormone, thyroxine (T4). Postpartum thyroiditis—inflammation of the thyroidgland—causes a brief period ofhyperthyroidism, often followed byhypothyroidism that usually goesaway within a year. Sometimes thehypothyroidism is permanent.
Hope through ResearchFor More InformationThe National Institute of Diabetes andDigestive and Kidney Diseases (NIDDK)conducts and supports research into manykinds of disorders, including thyroid disease.Researchers are investigating the development, signs and symptoms, and genetics ofthyroid function disorders to further understand thyroid diseases. Scientists continue tostudy treatment options for pregnant womenwith thyroid disorders, as well as long-termoutcomes for mothers and their children.American Association of ClinicalEndocrinologists245 Riverside Avenue, Suite 200Jacksonville, FL 32202Phone: 904–353–7878Fax: 904–353–8185Internet: www.aace.comParticipants in clinical trials can play a moreactive role in their own health care, gainaccess to new research treatments beforethey are widely available, and help othersby contributing to medical research. Forinformation about current studies, visitwww.ClinicalTrials.gov.American Thyroid Association6066 Leesburg Pike, Suite 550Falls Church, VA 22041Phone: 1–800–THYROID (1–800–849–7643)or 703–998–8890Fax: 703–998–8893Email: thyroid@thyroid.orgInternet: www.thyroid.orgThe Endocrine Society8401 Connecticut Avenue, Suite 900Chevy Chase, MD 20815Phone: 1–888–363–6274 or 301–941–0200Fax: 301–941–0259Email: societyservices@endo-society.orgInternet: www.endo-society.orgGraves’ Disease FoundationP.O. Box 2793Rancho Santa Fe, CA 92067Phone: 1–877–643–3123Fax: 858–756–5302Email: gravesdiseasefd@gmail.comInternet: www.ngdf.orgThe Hormone Foundation8401 Connecticut Avenue, Suite 900Chevy Chase, MD 20815–5817Phone: 1–800–HORMONE(1–800–467–6663)Fax: 301–941–0259Email: hormone@endo-society.orgInternet: www.hormone.org10 Pregnancy and Thyroid Disease
AcknowledgmentsPublications produced by the Clearinghouseare carefully reviewed by both NIDDK scientists and outside experts. This publicationwas originally reviewed by Lewis Braverman,M.D., Boston Medical Center, and LindaBarbour, M.D., M.S.P.H., University ofColorado Denver. Dr. Braverman reviewedthe updated version of the publication.You may also find additional information about thistopic by visiting MedlinePlus at www.medlineplus.gov.This publication may contain information aboutmedications. When prepared, this publicationincluded the most current information available.For updates or for questions about any medications,contact the U.S. Food and Drug Administration tollfree at 1–888–INFO–FDA (1–888–463–6332) or visitwww.fda.gov. Consult your health care provider formore information.The U.S. Government does not endorse or favor anyspecific commercial product or company. Trade,proprietary, or company names appearing in thisdocument are used only because they are considerednecessary in the context of the information provided.If a product is not mentioned, the omission does notmean or imply that the product is unsatisfactory.11 Pregnancy and Thyroid Disease
The National Endocrineand Metabolic DiseasesInformation Service6 Information WayBethesda, MD 20892–3569Phone: 1–888–828–0904TTY: 1–866–569–1162Fax: 703–738–4929Email: endoandmeta@info.niddk.nih.govInternet: www.endocrine.niddk.nih.govThe National Endocrine and MetabolicDiseases Information Service is aninformation dissemination service of theNational Institute of Diabetes and Digestiveand Kidney Diseases (NIDDK). TheNIDDK is part of the National Institutes ofHealth, which is part of the U.S. Departmentof Health and Human Services.The NIDDK conducts and supportsbiomedical research. As a public service, theNIDDK has established information servicesto increase knowledge and understandingabout health and disease among patients,health professionals, and the public.This publication is not copyrighted. The Clearinghouse encourages users of this publication to duplicate and distribute as many copies as desired.This publication is available atwww.endocrine.niddk.nih.gov.U.S. DEPARTMENT OF HEALTHAND HUMAN SERVICESNational Institutes of HealthNIH Publication No. 12–6234April 2012The NIDDK prints on recycled paper with bio-based ink.
Aug 11, 2011 · Thyroid hormone is critical to normal development of the baby’s brain and nervous system. During the irst trimester, the fetus depends on the mother’s supply of thyroid hormone, which comes through the placenta. At around 12 weeks, the baby’s thyroid
Welcome to Healing Hashimoto’s, a Savvy Patients Guide! A lot has happened in the thyroid world since Hy Bender and I wrote The Complete Idiot’s Guide to Thyroid Disease. Since the rate of new cases of thyroid disease is only increasing, many still need introductory material as found in The Complete Idiot’s Guide to Thyroid Disease.
2 shows the position of the thyroid gland as well as right and left lobe for a human being. Measurement of the thyroid in-volves three measurements, which are the width, depth and length [7]. The normal thyroid gland is 2cm or less in width and depth and 4.5 – 5.5 cm in length. 2.2 Fig. 2. Position of thyroid gland. [20]File Size: 600KBPage Count: 8
the adult thyroid gland varies between 15g and 30g, and each of the major lobes is around 4cm long and 2cm wide (Benvenga et al, 2018; Dorion, 2017). Embedded in the posterior portion of the thyroid are four tiny parathyroid glands, which function independently of the thyroid (Fig 1). Histology The thyroid contains two major popula-
In order to measure normal thyroid gland in Sudanese. 1.4 Specific objectives: -To measure thyroid gland volume (right lobe, left lobe) and isthmus. -To correlate size of thyroid gland with body characteristics (age, gender, height and weight). -To find dynamic equation to calculate measurement of thyroid using body characteristics.
Thyroid antibodies in hypothyroidism In most instances, it is not necessary or recommended to check thyroid antibodies Elevated levels of thyroid antibodies may indicate that a patient with normal TSH and normal free T4 is more predisposed to develop hypothyroidism Elevated levels of thyroid antibodies do not indicate –
of 1432 Japanese with normal thyroid function [i.e., normal range of free triiodothyronine (free T3) and free . [the first quartile, third quartile]. Normal range of measurements are ( ) Table 2 Thyroid-related hormone by anti-thyroid peroxidase antibody (TPO-Ab) Anti-thyroid peroxidase antibody (TPO-Ab) p Total No. of participants 1165 267
Introduction by Suzy Cohen, RPh xiii Part I Thyroid Basics 1 Chapter 1 One Gland with a Big Job 3 Chapter 2 Thyroid Hormones Control the Show 13 Chapter 3 Thyroid on Fire 27 Part II Thyroid Testing 43 Chapter 4 Limitations of the TSH Test 45 Chapter 5 The Best Lab Tests 49 Chapter 6 5 WaysYour Doctor MisdiagnosesYou 73 Part III Drug Muggers 81
WHAT IS MY SECOND GRADE STUDENT LEARNING IN MODULE 1? Wit & Wisdom is our English curriculum. It builds knowledge of key topics in history, science, and literature through the study of excellent texts. By reading and responding to stories and nonfiction texts, we will build knowledge of the following topics: Module 1: A Season of Change Module 2: American West Module 3: Civil Rights Heroes .
