But the problem remains two fold: the need for recognition that low thyroid function very often can provoke menstrual problems, and the need for recognition, too, that hypothyroidism may be present despite laboratory tests suggesting it is not.

The medical literature is full of reports going back many years that provide evidence that thyroid medication, used when indicated, is one of the most helpful measures in the treatment of infertility in both men and women. And not infrequently it may be needed by both partners in an infertile marriage.

Forty years ago, after many years of successful use of thyroid therapy, leading gynecologists in this country and elsewhere were reporting thyroid had cured more menstrual disorders than all other medications combined. Unfortunately, that lesson seems to have been largely lost.

Thyroid secretions in adequate amounts appear to be essential for development of the egg and for proper ovarian secretions. If thyroid function is low, an egg may be discharged from an ovary but it may not be fertilizable or, if fertilized, may not be capable of nesting so that pregnancy is quickly aborted.

On thyroid therapy, more than 90 percent of those with painful menstruation were relieved, most of them completely. The results were fully as good in converting irregular periods to normal, regular ones. And in six of seven women with excessive flow, normal flow was established.

In study at the Mayo Clinic covering fifty consecutive young women with hypothyroidism, twenty-eight has menstrual disturbances. Abnormally profuse menses was a common disturbance; frequent bleeding between periods was another; in some cases, both problems were present. Thyroid therapy relived the disturbances.

Certainly miscarriage is not invariably related to low thyroid function. There are many other possible causes. Yet soon after thyroid therapy first became available, it was found that patients with a history of miscarriages often had a history compatible with thyroid deficiency and that full-term pregnancies might follow treatment with thyroid.