Hypothyroidism During Pregnancy
Lydia Lebron
Composition I ENG201
Jersey College
School of Nursing
Teterboro Campus
Professor Toni S. Taylor, MSW
Winter 2013
January 24,2014

Abstract

Hypothyroidism during pregnancy is very dangerous for both mother and unborn child. There are several complications that the fetus can develop if left untreated. Many times hypothyroidism goes undiagnosed due to its symptoms similar to pregnancy. Thyroid hormones play a crucial role in pregnancy for fetus brain and developmental growth as well as the mother’s health. With the right medical management hypothyroidism and subclinical hypothyroidism during pregnancy can prevent fetal birth defects by mandated prescreening before, during, after pregnancy postpartum thyroiditis, educating the patient about medical treatment, medication and diet requirements and restrictions.

Introduction

“An ounce of prevention is worth a pound of cure.”—Benjamin Franklin. Hypothyroidism during pregnancy is often overlooked. Women with thyroid problems are asymptomatic and not routinely screened even during and after pregnancy (Braverman, 2012). Thyroid hormones play a critical role during pregnancy both in the development of a healthy baby and maintaining the health of the mother. With proper management, hypothyroidism, subclinical hypothyroidism and postpartum thyroiditis during pregnancy can prevent fetal birth defects and health complications to the mother by mandatory screening, education, diet requirements/restrictions, and medical/medication treatment. Health care providers diagnose hypothyroidism in pregnancy through a careful review of symptoms and blood serum measurement of thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels (Buckley, 2012). Symptoms of hypothyroidism in pregnancy include extreme fatigue, cold intolerance, muscle cramps, constipation, depression, mood swings and problems with memory or concentration. High levels of the TSH and low levels of the free T4 generally indicate hypothyroidism (Buckley, 2012). Because of normal pregnancy related changes in the thyroid function, test results must be interpreted with caution.
The TSH test can also identify subclinical hypothyroidism, which is a mild form of hypothyroidism that has no apparent symptoms and is permanent even after pregnancy. It also requires a lifelong treatment with synthetic thyroid hormone. According to the U.S. Department of Health and Human Services (2012), subclinical hypothyroidism occurs in 2 to 3 percent of pregnancies. Test results will show high levels of TSH and normal free T4.

Types of Hypothyroidism during Pregnancy

Experts differ in their opinions as to whether asymptomatic pregnant women should be routinely screened for hypothyroidism. But if subclinical hypothyroidism is discovered during pregnancy, treatment is recommended to help ensure a healthy pregnancy (Zimmerman MB 2009).
Postpartum thyroiditis is an inflammation of the thyroid that affects about 4 to 10 percent of women during the first year after giving birth (The National Institute of Diabetes and Kidney Diseases, 2012). Thyroiditis causes stored thyroid hormone to leak out of the inflamed thyroid gland and raise hormone levels in the blood. Postpartum thyroiditis is believed to be an autoimmune condition and causes mild hyperthyroidism that usually lasts 1 to 2 months (Ogunyemi DA, 2011). Many women then develop hypothyroidism lasting 6 to 12 months before the thyroid regains normal function (Ogunyemi DA, 2011).
In some women, the thyroid is too damaged to regain normal function and their hypothyroidism is permanent, requiring lifelong treatment with synthetic thyroid hormone (Buckley, 2012). Postpartum thyroiditis is likely to recur with future pregnancies. Postpartum thyroiditis often goes undiagnosed because the symptoms are mistaken for postpartum blues—the exhaustion and moodiness that sometimes follow delivery (NIDDK, 2012). If symptoms of fatigue and lethargy do not go away within a few months or a woman develops postpartum depression, she should talk with her health care provider (NIDDK, 2012). If the hypothyroid symptoms are bothersome, thyroid medication can be given. Therapeutic requirements for exogenous thyroxine (i.e., primary hormone secreted by the thyroid gland) increase by ~ 50% during pregnancy. In the U.S., ~ 2% of pregnant women are diagnosed with hypothyroidism; subclinical hypothyroidism affects another 0.5% of pregnant women. Additionally, 1–2% of pregnant women are already receiving thyroid hormone replacement therapy. Six percent of miscarriages are associated with hypothyroidism (Buckley, 2012). Hypothyroidism in pregnancy, even subclinical, is associated with the increased risk for maternal and fetal complications. Potential maternal complications include anemia, postpartum hemorrhage, cardiac dysfunction, preeclampsia, placental abruption, infertility, and miscarriage; potential fetal/neonatal complications include fetal distress during labor, mental retardation, prematurity, low birth weight, birth defects, and death (Buckley, 2012).
Fetal Birth Defects
Babies born to women with untreated hypothyroidism are also at increased risk for cleft palate and for heart, brain, and kidney impairment (Stagnaro-Green, A.2011). According to a 2010 study, apoptosis (i.e., programmed cell death) is abnormally accelerated during pathologic phases of developing clinical hypothyroidism, which can cause permanent fetal growth retardation in cases of maternal hypothyroidism (Özoğul et al., 2010). The American College of Obstetricians and Gynecologists recommends against routine screening and treatment of subclinical hypothyroidism during pregnancy because of lack of supporting evidence (Buckley, 2012). Findings from a research study demonstrated an association between impaired maternal thyroid (at 11 and 13 weeks of gestation) and predisposition towards late-onset preeclampsia (Ashoor et al., 2010).
Medical and Medication Treatment
Hypothyroidism is treated with synthetic thyroid hormone called thyroxine. It’s a medication that is identical to the T4 hormone made by the thyroid gland. Women with preexisting hypothyroidism will need to increase their pre-pregnancy dose of thyroxine to maintain normal thyroid function. Thyroid function should be checked every 6 to 8 weeks during pregnancy. Synthetic thyroxine is safe and necessary for the well being of the fetus if the mother has hypothyroidism (Braverman L. 2012).
Synthetic thyroxine medication is to be taken early in the morning on an empty stomach with a full glass of water. The patient is advised not to take any preparations, medications, and vitamin supplements that contain iron or calcium within 4 hours of levothyroxine (synthetic thyroxine generic name of medication). They are also advised to avoid soy products, which interrupts the absorption of levothyroxine and can cause a goiter to enlarge if diet doesn’t contain enough iodine (Casey, B.M.2011).
Diet Requirements and Restrictions During pregnancy, the body requires higher amounts of some nutrients to support the health of the mother and growing baby. Experts recommend pregnant women maintain a balanced diet and take a prenatal multivitamin and minerals supplement containing iodine to receive most nutrients necessary for thyroid health (NIDDK, 2012). Because the thyroid uses iodine to make thyroid hormone, iodine is an important mineral for a mother during pregnancy. During pregnancy, the baby gets iodine from the mother’s diet:
Women need more iodine when they are pregnant-about 250 micrograms a day. In the United States, about 7 percent of pregnant women may not get enough iodine in their diet or through prenatal vitamins. Choosing iodized salt-salt supplemented with iodine-over plain salt and prenatal vitamins containing iodine will ensure this need is met. However, People with autoimmune thyroid disease may be sensitive to harmful side effects from iodine. Taking iodine drops or eating foods containing large amounts such as seaweed, dulse, or kelp may cause or worsen hyperthyroidism and hypothyroidism (National Library of Medicine, 2012).
The U.S. recommended daily allowance for iodine during pregnancy and lactation is 175–250 µg. Many prenatal multivitamin formulations provide this amount (NIDDK, 2012). With strict medication compliance, recommended dietary restrictions (e.g., avoid mercury- or PCB-containing fish), continued medical surveillance during pregnancy and postpartum for mother and infant, and accurate records of infant growth and developmental milestones (DynaMed, 2013). The patient is to report any side effects or any new symptoms that may have developed when taking the medication to their healthcare provider.
Conclusion
In conclusion, with proper medical management hypothyroidism during pregnancy will not be overlooked. Mandated blood screenings of thyroid disease during pregnancy and after birth can lessen potential complications for both mother and baby. Providing information on diet requirements and restrictions can promote a healthy baby and mother. Educating the patient about the proper use of medication during and after pregnancy can prevent fetal defects and improve blood levels.

References
Ashoor, G., (2010). Maternal thyroid function at 11 to 13 weeks of gestation and subsequent development of preeclampsia. Prenatal Diagnosis, 30(11), 1032-1038. doi:10.1002/pd.2566
Bannerman, C. (2011). Basic science and clinical evidence regarding treatment of subclinical hypothyroidism during pregnancy. Clinical Obstetrics and Gynecology, 54(3), 488-492. doi:10.1097/GRF.0b013e3182272fca
Braverman, L., MD. Boston Medical Center (2012) Pregnancy and Thyroid disease
Buckley L. BS, MD (2012), Hypothyroidism in Pregnancy, Cinahl Information Systems, Glendale, CA
Casey, B. M. (2011). Subclinical thyroid dysfunction during pregnancy. Clinical Obstetrics and Gynecology, 54(3), 493-498. Doi: 10.1097/GRF.0b013e31822e27e3

DynaMed. (2013, July 22). Hypothyroidism. Ipswich, MA: EBSCO Publishing. Retrieved August 13, 2013
Ogunyemi, D. A. (2012, March 8). Autoimmune thyroid disease and pregnancy. Medscape reference. Retrieved August 13, 2013
Özoğul, C (2010). Maternal hypothyroidism and its role in the placenta: A morphometric and immunohistochemical study. Turkiye Klinikleri Journal of Medicine Sciences, 30(3), 970-7. Doi: 10.5336/medsci.2008-10086
Stagnaro-Green, A. (2011). Overt hyperthyroidism and hypothyroidism during pregnancy. Clinical Obstetrics and Gynecology, 54(3), 478-487. Doi: 10.1097/GRF.0b013e3182272f32
The National Institute of Diabetes and Digestive and Kidney Disease (NIDDK)(2012) National Endocrine and Metabolic Diseases Information Service
The National Library of Medicine in the fact sheet, Iodine in the diet, available at www.nlm.nih.gov/medlineplus.
U.S. Department of Health and Human Services (2012) NIH Publication No. 12-6234
Zimmerman MB. (2009) Iodine deficiency in pregnancy and the effects of maternal iodine supplementation on the offspring: a review. American Journal of Clinical Nutrition. 89(2):668S-672S