Thyroid-Related Infertility

What Can A Malfunctioning Thyroid Gland Do?

The malfunction of the thyroid can alter the balance of reproductive hormones in the body and, as a result, stop ovulation. Hyperthyroidism- an overactive thyroid-poses concern during pregnancy, causing miscarriages, premature births, and intrauterine growth retardation in undiagnosed and untreated cases.

The good news is that hyper- and hypothyroidism, when managed properly, need not affect fertility or pregnancy. By keeping thyroid levels under control through medication, getting regular professional care, and maintaining excellent self-care, a successful outcome can be in the offing. Education about thyroid dysfunction and its relationship to fertility and pregnancy is an important key in ensuring an uneventful pregnancy.

How Thyroid Disease Affects Fertility

Thyroid disease can affect fertility by causing anovulation (no ovulation or release of an egg) and irregularities in menses. If there is no egg to fertilize, then conception is out of the question. Thyroid dysfunction upsets the body's ability to produce certain hormones affecting ovulation. The pituitary gland produces a hormone called luteining hormone or LH. LH stimulates the release of an egg from the ovaries and that egg is then available for fertilization. If there is a deficiency or overabundance of thyroid hormone, it will affect LH and there may be no ovulation. Even though a woman is menstruating regularly, she may not be ovulating. Unfortunately, that fact may not be known until a long period of infertility has passed.

The Thyroid Connection In LPD

A short luteal phase, called luteal phase defect, can also cause inadequacy in the uterus to hold a fertilized egg. In LPD, often there is not enough endometrial tissue to sustain pregnancy. This, too, can be generated by thyroid dysfunction. Hypothyroidism, the inactivity of the thyroid gland, can cause an increase in the hormone prolactin, which is produced by the pituitary gland and is important to the production of breast milk in post-partum women. Excess prolactin may prevent ovulation, and cause irregular, or absent monthly cycles. An elevation in the hormone TRH (thyrotropin releasing hormone) produced in the hypothalamus may be the culprit in such cases. Hypothyroidism is also implicated in PCOS, another cause of infertility.

Proper Testing Reveals Problems-Check Your TSH

To determine whether the thyroid is the problem when it comes to fertility, the TSH (thyroid stimulating hormone) levels are key. A TSH test will indicate the level of hormone in the body. While many labs feel the right level is between .5 to 5.5 TSH, there seems to be a move among endocrinologists to lower the numbers to .3 to 3.0. Often a woman with some evidence of thyroid disease is unable to conceive or maintain a pregnancy with a level higher than 1.0 to 2.0. It is very important that an endocrinologist with extensive experience in the treatment of thyroid-related infertility be involved in the diagnosis and treatment.

Thyroid disease need not rob a woman of the experience of pregnancy and birth. Proper diagnosis, treatment, and maintenance will help her go the distance.