Thyroid Disease and Pregnancy

Thyroid disease affects different aspects ofcontrol her hyperthyroidism.
pregnancy and postpartum health for the mother and- Uncontrolled hyperthyroidism remains despite
the newborn child. There have been varied andtreatment. If the above cases are evident, surgery is
contradicting practices with regards to thyroid diseaserecommended usually during the second trimester. The
and pregnancy. As a result a group of endocrinologistssecond trimester for this operation poses less risk to
came together to publish a journal containing clinicalthe unborn child and danger to the pregnancy.
guidelines for the management of thyroid problemsTreating subclinical or mild hyperthyroidism has not
during pregnancy and during the postpartum period.been shown to improve or better the outcome of
The creation of this group came about over apregnancy. Therefore, treating subclinical or mild
two-year period and their findings were published in thehyperthyroidism is not because of the potential
Journal of Endocrinology and Metabolism, the Augustnegative effects on the unborn child.
of 2007 issue. This journal represents the methodsNote: Radioactive iodine should never be administered
and practices of endocrinologists all over the world.to any woman who is or may be pregnant.
Some of the main components of that journal areAntibodies, Graves' Disease and Newborns
being discussed below. The points bear crucialThere are two antibodies in a mother that can cross
implications for women who are diagnosed with thyroidthe placenta and affect the unborn child's thyroid gland.
disease during their pregnancy or even at theThey are called TSH receptor-stimulating or TSH
postpartum stage. Some of the information also has areceptor-binding antibodies. If a woman is diagnosed
bearing on women who develop thyroid diseasepositive for any of these antibodies while pregnant, her
before they get pregnant.child can be born with hyperthyroidism. It is very
Hypothyroidism & Pregnancyimportant that these antibodies be measured in both
The condition of hypothyroidism in a mother or anwomen who have Graves' disease or who have
unborn child can cause serious health problems on thegiven birth previously to newborn children who
unborn baby. If a woman is aware of her condition asdeveloped Graves' disease. It may be necessary to
properly diagnosed hypothyroidism, she shouldtreat the mother with anti-thyroid drugs in order to
reconsider trying to get pregnant or avoid maternalreduce any risk to the newborn child.
hypothyroidism altogether.If a woman has elevated TSH receptor-stimulating or
If a woman should develop hypothyroidism prior to herTSH receptor-binding antibodies and is treated with
pregnancy and it has been properly diagnosed by aanti-thyroid drugs, a doctor should conduct a fetal
doctor or endocrinologist, her thyroid medication willultrasound evaluation. This scan will search for any
need to be adjusted so that the thyroid stimulatingevidence of dysfunction in the thyroid gland of the still
hormone (TSH) level goes no higher than 2.5 prior todeveloping baby. Such would include finding any
entering pregnancy.evidence of slow growth and enlargement in the
A woman diagnosed as hypothyroid during herbaby's thyroid.
pregnancy should undergo treatment immediately. TheIf a new mother has been diagnosed with Graves'
goal is to restore her thyroid levels back to normal asdisease, her newborn child should still be evaluated
soon as possible. Upon entering the first trimester, herafter birth for any dysfunction in its thyroid gland.
thyroid-stimulating hormone (TSH) level should be heldPregnancy with Severe Morning Sickness and
at less than 2.5. Upon entering the second and thirdHyperthyroidism
trimester, her thyroid-stimulating hormone (TSH) shouldHyperemesis gravidarum is severe morning sickness
be maintained at less than 3.0. Thyroid function teststhat may also include dehydrations and significant
need to be reviewed and re-evaluated within 30 to 40weight loss. All pregnant women diagnosed with
days after the initial diagnosis.hyperemesis gravidarum should have their thyroid
When a pregnant woman reaches week four to six,gland examined for any dysfunction.
her thyroid medication dosage will almost always needIf a woman is diagnosed with overt hyperthyroidism
to be increased. It is possible that her dosage willdue to Graves' disease and gestational
increase by anywhere from thirty to fifty percent.hyperthyroidism with substantially elevated thyroid
Some women have a thyroid auto-immunity as inhormone levels treatment may be required.
cases where she has been previously examined andThyroid Nodules, Thyroid Cancer & Pregnancy
found to be positive for thyroid antibodies. WomanA fine-needle aspiration (FNA) biopsy evaluation is
who have an auto-immunity and who possess normalrecommended for pregnant women with thyroid
thyroid stimulating hormone (TSH) levels in early stagesnodules measuring larger than 1 cm in size.
of pregnancy can still be at risk of becomingOnce a pregnant woman is diagnosed with malignancy
hypothyroid at any point in the pregnancy. It isor cancerous thyroid nodules and they are such
recommended that she be monitored regularlynodules are found during the first or second trimester,
throughout the pregnancy for elevated thyroidsurgery should be recommended in the second
stimulating hormone (TSH).trimester.
If a woman is diagnosed with subclinical hypothyroidismNote: Well-differentiated thyroid cancers grow at a
which involves a thyroid stimulating hormone (TSH)much slower rate. If the evaluation or biopsy shows
level above normal with normal free T4 levels, herthe cancer to be papillary or follicular without any
condition can lead to a negative health outcome forevidence of advanced disease, a woman may be able
her and her unborn child. Immediate treatment of theto choose having the surgery after childbirth.
mother can help to ensure a healthier pregnancy andA pregnant woman previously diagnosed with thyroid
birth outcome. However, treatment has not beencancer or a woman (as in the above case) diagnosed
proven to guarantee long-term neurologicalwith a well-differentiated thyroid cancer opting to have
development of the baby. In spite of this, expertssurgery after her child is born can still receive
believe that the possible benefits of treatment stilltreatment that can help to suppress thyroid stimulating
outweigh any possible risks if the mother went withouthormone (TSH). Though her thyroid stimulating
treatment. The consensus is that treatment ishormone (TSH) level may be suppressed, it would still
recommended even in women with subclinicalbe detectable. The desirable situation is to have free
hypothyroidism.T4 or total T4 levels remain within the normal range
Once childbirth has occurred, most women who havefor the pregnancy.
been diagnosed with hypothyroidism will need to haveNote: Radioactive iodine should never be administered
their medication dosage reduced.to women who are breastfeeding.
Hyperthyroidism & PregnancyWomen who are receiving therapeutic doses of
It has been found that hyperthyroidism can be broughtradioactive iodine should wait a minimum of six months
on by Graves' disease. Transient hyperthyroidism canand up to a year before becoming pregnant. This will
also trigger hyperemesis gravidarum, which is aensure stability of thyroid function and that the cancer
condition of pregnancy that causes severe morningis in remission.
sickness. The diagnosis involves determining whether aPostpartum Thyroid Problems After Pregnancy
woman has a goiter, tests positive for thyroidA thyroid evaluation should be conducted three to six
antibodies or both.months after a woman has given birth if she has
If a pregnant woman's hyperthyroidism is triggered byalready tested positive for thyroid peroxidase
Graves' disease or nodules are found in the gland, sheantibodies.
should begin treatment for hyperthyroidism immediately.In women with type 1 diabetes, postpartum thyroiditis is
Generally, pregnant women are given anti-thyroidthree times more likely to occur. That being the case,
medication as part of treatment especially when initiallywoman with type 1 diabetes should have thyroid
diagnosed.evaluation three months and six months after childbirth.
The most common antithyroid medication given usuallyWomen who already have a history of postpartum
during the first trimester is propylthiouracil.thyroiditis have a significantly increased risk of
Propylthiouracil is generally the drug of choice becausedeveloping hypothyroidism within five to ten years
methimazole contains has a slightly higher risk of birthafter a postpartum thyroiditis episode. Any women
defects. Methimazole is used, but it is only prescribed ifthat fall into this group should have their thyroid
propylthiouracil is not available or if a woman ischecked and evaluated annually.
experiencing complications with it.Screening for Thyroid Dysfunction During Pregnancy
There are situations where surgery may be the onlyIn particular, women who face a higher risk of thyroid
recommended method for treatment instead of drugs.disease should be screened and evaluated. It is
They are:recommended that these evaluations occur in women
- If there is a severe negative reaction to anti-thyroidwho are having an infertility evaluation.
drugs.It is also recommend that women who fall into the
- If a woman requires an extremely high dosage toat-risk groups below be evaluated.