Synthroid Side Effects in Pregnancy

Synthroid is also known as levothyroxine. It is often given to patients who have hypothyroidism, meaning that their thyroid does not produce enough thyroid hormone. Because hypothyroidism can be a long-lasting condition, many patients that take synthroid have to take it their whole lives. As a result, if a female is taking the drug and wishes to become pregnant, she will need to understand the effects of synthroid on a pregnancy.

General Side Effects

The most common side effects seen with the use of synthroid are nervousness, insomnia and palpitations of the heart. Other side effects include headaches, increased appetite, and, paradoxically, weight loss. This is because a synthroid works to speed up the body's metabolism.

Effects on Pregnancy

Synthroid has been designated by the Food and Drug Administration as a Class A drug for pregnancy. This means that it is safe for pregnant mothers to take, as it won't affect the baby. It is also safe for mother's who are breastfeeding to take. While the drug does enter into the breast milk, it does not affect the infant.

Synthroid and Vitamins

One way in which synthroid can effect pregnancy is due to the way it interacts with vitamins. It has been found that people who are taking calcium or iron supplements, or are eating lots of soy protein absorb less synthroid. Because many pregnant women take these minerals as part of their pre-natal vitamins, they may need to take higher doses of synthroid.

Synthroid and Weight Loss

The thyroid hormone regulates metabolism, and, since synthroid replaces thyroid hormone, taking synthroid can cause an increase in metabolism. As a result, pregnant women taking synthroid may begin to lose weight. This can be problematic because weight loss can make it difficult for the mother's body to support the fetus.

Synthroid and Anxiety

Synthroid can cause feelings of insomnia and anxiety, as well as interfere with some antidepressants. Because pregnancy is already a stressful time for a woman, synthroid can cause significant feelings of concern for a pregnant woman. In extreme cases, it may cause the mother to feel that "something is wrong" with the pregnancy, or have other worries.