The main test used to detect hypothyroidism is measuring blood levels of TSH. An elevated TSH level usually means the thyroid gland is not making enough thyroid hormone, and the pituitary gland has responded by making more TSH to try to get the thyroid hormone levels where they should be.
Other blood tests include measuring T4 and thyroid autoantibodies. Antibodies are substances made by your immune system, usually to protect you against bacterial and viral infections. Sometimes, however, the immune system can make antibodies against your own body—such as against your thyroid. T4 is a hormone produced directly by the thyroid gland.
It is typically low in patients with hypothyroidism. An autoantibody is an antibody that attacks the cells and tissues of the organism that made it. Hypothyroidism can prevent the release of the egg from the ovary ovulation. Typically, for women who have periods menstruate each month, an egg is released from the ovary each month.
But women who have hypothyroidism may release an egg less frequently or not at all. Many symptoms of the condition are similar to pregnancy symptoms.
For example, they can both cause fatigue, weight gain, and changes in menstruation. Having low thyroid hormone levels can also cause problems with becoming pregnant. It can also be a cause of miscarriage. Hypothyroidism is a common condition. It can go undetected if symptoms are mild. The thyroid doesn't make enough thyroid hormones. Symptoms may be mild and may start slowly.
The most common symptoms include:. The symptoms may be like other health problems. Chief among them is the TSH test , which measures the level of thyroid stimulating hormone in your blood. Ideally, thyroid disease should be diagnosed and properly treated prior to conception. And if you're being treated for hypothyroidism and planning to conceive, before you get pregnant, you and your healthcare provider should have a plan to confirm your pregnancy as early as possible and to increase your dosage of thyroid hormone replacement as soon as your pregnancy is confirmed.
Different types of thyroid conditions have different issues when it comes to managing them in pregnancy. When your thyroid can't keep up during pregnancy, your TSH level will go up in underactive thryoid conditions, indicating a hypothyroid underactive state.
If it's left untreated or insufficiently treated, your hypothyroidism can cause miscarriage, stillbirth, preterm labor, and developmental and motor problems in your child.
The ATA recommendation is that, before you get pregnant, your healthcare provider should adjust your dosage of thyroid hormone replacement medication so that your TSH is below 2. Using Synthroid levothyroxine during pregnancy is safe for your baby since the drug mimics your thyroid's natural thyroxine T4 hormone. According to the ATA guidelines, thyroid hormone replacement increases should start at home as soon as you think you're pregnant ask your healthcare provider for instructions on this and continue through to around weeks 16 to 20, after which your thyroid hormone levels will typically plateau until delivery.
You'll need thyroid tests every four weeks during the first half of pregnancy and then again between weeks 26 and 32 to make sure your TSH is at a good level. Following delivery, your medication doses will need to be reduced to pre-pregnancy levels with follow-up monitoring six weeks after the delivery date.
Hashimoto's disease, also known as Hashimoto's thyroiditis, is an autoimmune disease that attacks and gradually destroys your thyroid. Hypothyroidism is a common outcome of Hashimoto's, so if you're hypothyroid, you'll need the same treatment plan mentioned above. That said, additional attention should be made to keeping your TSH level under 2. The higher your TSH level is, the more your risk of miscarriage increases.
When you also have thyroid antibodies, research published in shows that the risk of miscarriage increases even more significantly if your TSH level gets above 2. If you have lower-than-normal TSH levels while you're pregnant, this shows that your thyroid is overactive, so your healthcare provider should test you to determine the cause of your hyperthyroidism.
It could be a temporary case that's associated with hyperemesis gravidarum a condition of pregnancy that causes severe morning sickness , Graves' disease an autoimmune thyroid disorder that's the most common cause of hyperthyroidism , or a thyroid nodule. During pregnancy, hyperthyroidism is most often caused by either Graves' disease or temporary gestational hyperthyroidism, so your healthcare provider will need to differentiate between these two.
This can be a bit tricky since you can't have a radioactive iodine uptake scan of your thyroid while you're pregnant because of the risk it poses to your baby.
Your practitioner will need to rely on your medical history, a physical exam, clinical signs and symptoms, and blood tests to determine the cause of your hyperthyroidism.
If you've been vomiting, have no prior history of thyroid disease, your hyperthyroid symptoms are generally mild, and there's no evidence of swelling in your thyroid or the bulging eyes that can accompany Graves' disease, your healthcare provider will probably chalk your hyperthyroidism up to temporary gestational hyperthyroidism.
A blood test to check for elevated levels of the pregnancy hormone human chorionic gonadotropin hCG may also confirm this diagnosis since extremely high hCG levels are often found with hyperemesis gravidarum and can cause temporary hyperthyroidism.
These blood tests can usually narrow down the cause of your hyperthyroidism so that your healthcare provider can treat it appropriately. Leaving hyperthyroidism untreated can result in high blood pressure, thyroid storm , congestive heart failure, miscarriage, premature birth, low birth weight, or even stillbirth. For pregnant and non-pregnant patients, treatment typically begins with taking antithyroid medications. In cases where you're already being treated with a low dose of antithyroid medication and your thyroid function is normal, your healthcare provider may take you off your medication, at least during your first trimester when your baby is most susceptible.
You'll need to be monitored closely, having your TSH and FT4 or TT4 checked every one to two weeks during the first trimester and every two to four weeks during the second and third trimesters, as long as your thyroid function remains normal. Otherwise, if you've been newly diagnosed, you haven't been taking antithyroid medication for very long, or you're at a high risk of developing thyrotoxicosis a condition that occurs from having too much thyroid hormone in your system , your dosage will likely be adjusted so that you're on the lowest possible dose of antithyroid medication while still keeping your free T4 at the top end of the normal range or just above it.
This protects your baby from overexposure since these medications are more potent for him or her than they are for you. The antithyroid drug of choice during the first 16 weeks of pregnancy is propylthiouracil PTU because methimazole MMI has a higher though small risk of causing birth defects in your baby. It's unclear which one is better after 16 weeks, so your practitioner will likely make a judgment call if you still need antithyroid medication at this point.
In cases where you have an allergic or serious reaction to both types of antithyroid drugs, you require very high doses to control your hyperthyroidism, or your hyperthyroidism is uncontrolled despite treatment, a thyroidectomy thyroid surgery may be recommended.
The best time for a thyroidectomy is during your second trimester when it's least likely to endanger your baby. You should never have radioactive iodine RAI treatment if you are or might be pregnant because of the risks to your baby. And if you've had RAI, you should put pregnancy off for a minimum of six months after treatment.
Whether you have active Graves' disease or you had it in the past, your baby has a higher risk of developing hyperthyroidism or hypothyroidism, either in utero fetal or after birth neonatal. The factors that can affect these risks include:. A TRAb value that's more than three times above the upper limit of normal is considered a marker for follow-up of your baby, ideally involving a practitioner who specializes in maternal-fetal medicine.
During your first trimester, if your TRAb levels are elevated, your healthcare provider will need to keep a close eye on them throughout your pregnancy so that your treatment can be tailored to best minimize risk to both you and your baby.
These should look for evidence of thyroid dysfunction in your developing baby, like slow growth, fast heart rate, symptoms of congestive heart failure, and an enlarged thyroid. In fact, the ATA recommends that all newborns be screened for thyroid dysfunction two to five days after birth. Thankfully, the vast majority of thyroid nodules aren't cancerous. The ATA advises pregnant women with thyroid nodules to have their TSH level measured and to get an ultrasound to determine the features of the nodule and monitor any growth.
If you have a family history of medullary thyroid carcinoma or multiple endocrine neoplasia MEN 2, your healthcare provider may also look at your calcitonin level, though the jury is still out as far as how helpful this measurement really is. You may also have a fine-needle aspiration FNA biopsy of the nodule s , especially if your TSH level isn't lower than normal. In cases where you have a nodule and your TSH is below normal, your practitioner may put the FNA off until after you have your baby, but since it's considered safe during pregnancy, you can have an FNA done anytime.
When your thyroid nodule s is causing hyperthyroidism, you may need treatment with antithyroid medications. This will run along the same lines as anyone else with hyperthyroidism: Your healthcare provider will put you on the lowest possible dose to keep your FT4 or TT4 on the high end to somewhat above the normal range to minimize risks to your baby. When cancerous thyroid nodules are discovered during the first or second trimester—particularly if related to papillary thyroid cancer, the most common type—your practitioner will want to monitor the cancer closely using ultrasound to see how and if it grows.
If there's a fair amount of growth before your 24th to 26th weeks of pregnancy, you may need to have surgery to remove it. If the cancer remains stable or it's discovered during the second half of your pregnancy, your healthcare provider will likely recommend waiting until after your baby is born to have surgery. In the case of anaplastic or medullary thyroid cancer, the ATA recommends that immediate surgery is seriously considered.
With any type of thyroid cancer, your practitioner will put you on thyroid hormone replacement medication, if you're not already taking it, and monitor you closely to keep your TSH within the same goal range as before you were pregnant. As discussed earlier, when you're pregnant, your thyroid increases in size and starts making more thyroid hormones to meet the needs of both mother and baby.
Pregnant women should get around mcg of iodine every day. While the majority of women of childbearing age in the United States are not iodine deficient, this is also the group that's the most likely to have a mild to moderate iodine deficiency.
Since it's difficult to pinpoint who might be at risk of iodine deficiency, the ATA, Endocrine Society, Teratology Society, and American Academy of Pediatrics all recommend that pregnant women take mcg potassium iodide supplements daily.
The exception: If you're taking levothyroxine for hypothyroidism, you don't need iodine supplements.
0コメント