The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

What is iodine?

Iodine is a trace element, a chemical element that is present in small amounts in the environment and in food. Like all elements it can exist in elemental form (molecules containing only iodine) or as part of chemical compounds (molecules containing iodine with other elements. In the diet, usually iodine occurs as iodide, which means an ion (charged particle) that is part of a salt, such as sodium iodide or potassium iodide. This is how it exists as an additive to table salt. Iodine is a needed component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). In order for your thyroid gland to make adequate amounts of these hormones during pregnancy, your body’s requirement for iodine increases. The requirement increases still more after you deliver, if you are breastfeeding. If you receive inadequate amounts of dietary iodine, you will not make enough T3 and T4 and your thyroid will swell up as a lump in the neck that can give you a cough and make swallowing difficult. This condition is called goiter and it can develop before there are other symptoms of reduced thyroid hormone levels, such as feeling cold and fatigued.

Is there a safe amount of iodine that I can consume during pregnancy?

During pregnancy, you should consume at least 220 mcg per day of iodide. Women at risk of not receiving enough are those who consume food grown in regions with low iodine levels in the soil (mountainous regions of Asia and South America) and those who avoid iodized salt. Also at risk are women who consume large amounts of foods that interfere with the movement of iodine into the thyroid, such as soy, cabbage, cassava, broccoli, and cauliflower. In North America, iodine deficiency is rare, but pregnant women occasionally develop mild to moderate iodine deficiency, with goiter, due to the increased need for iodine. Along with your thyroid, iodine is also vital to the development of the baby. This is why the need for iodine goes up during pregnancy.

Excessive intake of iodine can cause your thyroid to become too active. To avoid this problem you should not consume more than 1,100 mcg per day of iodide. The safe level for iodide during pregnancy is 220-1,100 mcg per day.

Can iodine consumption make it harder for me to get pregnant?

Excessive intake of iodine, amounts far above the daily requirement to the point that it gives you an overactive thyroid (hyperthyroidism) can make it harder for you to get pregnant. You also can have trouble getting pregnant if your male partner is hyperthyroid from consuming excessive amounts of iodine. Excessive iodine intake is very rare, however. Iodine deficiency, causing an underactive thyroid (hypothyroidism) also can reduce your fertility, so to optimize your ability to become pregnant, you should receive adequate but not excessive amounts of the element.

Can iodine cause a miscarriage?

Both too much and too little iodine can cause a miscarriage.

Can iodine during my pregnancy cause a birth defect?

Exposure to radioactive iodine that is used to treat certain thyroid conditions can lead to birth defects, but iodine deficiency is a more common cause of birth defects. Not enough iodine in the mother’s diet can lead to severe developmental abnormalities of the brain, with mental retardation, hearing problems, and other issues.

Are there long-term consequences to my baby from my iodine consumption?

As noted earlier, both excessive iodine and iodine deficiency can lead to long term problems for the baby

I just found out I am 6 weeks pregnant and last weekend consumed iodine. Will my baby have a problem?

No. You require iodine anyway for your health, and the health of the baby

Is binge consumption of iodine on only some days of the week as risky as consuming iodine everyday but at lower amounts?

Iodine is a nutrient and so you need to receive adequate, but not excessive amounts with your diet. Consuming excessive amounts is risky whether it is spread out or consumed all at once.

Is it ok to consume some iodine after the first trimester?

Yes. Iodine is a nutrient and so you need to receive adequate, but not excessive amounts with your diet.

Can a baby go through iodine withdrawal after birth?

No. There is no such thing as iodine withdrawal, since iodine is a nutrient, not a drug.

How will I know if iodine has hurt my baby?

If you consumed excessive amounts of iodine and the baby has an overactive thyroid, then the excessive iodine in your diet will be the reason.

Is there any hope for a baby who has been exposed to iodine throughout pregnancy?

Yes, as noted earlier, you and the baby both require some iodine for normal health and development.

Can I consume iodine while breastfeeding?

Yes.  Iodine is a nutrient and so you need to receive adequate, but not excessive amounts with your diet.

What if the father of the baby consumes iodine?

As with women, men need iodine in their diets.

Resources for iodine in pregnancy:

For more information about iodine during pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or read the following articles:

Mayo Clinic: Hypothyroidism and Pregnancy

World Health Organization:  Iodine supplementation in pregnant and lactating women  

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General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.

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