We have many patients that come to our practice with some sort of
history involving their thyroid gland. Some report histories of underactive thyroid,
some are overactive and some have autoimmune diseases such as Hashimoto's
or Graves' disease and some are only told that they have thyroid antibodies
but no act of thyroid disease but surprisingly most are incorrectly told
these reasons are not the reason for their recurrent miscarriages or failure
to conceive. We have learned that there are receptors on the developing
follicles for thyroid hormone and even small variations, high or low,
can affect the follicles growth, egg quality and ability to conceive.
In fact, new studies have actually found thyroid antibodies inside the
follicular fluid and the antibodies themselves may affect the egg quality.
Well, some of these variations in thyroid hormone are even more pronounced
in women with
polycystic ovarian syndrome. This is one of the reasons why we micromanage our patients with thyroid
dysfunction during any treatment cycle. Any patient with autoimmune thyroid
disease is at risk for recurrent pregnancy loss and there are at least
two mechanisms at play here.
First, the embryos need to develop immune tolerance so they can properly
implant. This is assisted by a healthy and correctly functioning maternal
immune system. The same defect in the mother's immune system that
allows her to start attacking her thyroid gland also deters the embryo's
ability to create immune tolerance for itself. If this immune tolerance
by the embryo is not correctly initiated, the mother's immune system
will attack the embryo much the same way it attacks her own thyroid gland.
Second, the anti-thyroid antibodies – even when there is no active
thyroid disease – have been shown to directly bind to the invading
portion of the embryo. This binding activates another part of the immune
system called the complement system and leads to a very strong immune
response against the embryo, as well as an increase of blood clots in
the developing embryo that also leads to recurrent pregnancy loss. So
you can see that any abnormality in thyroid testing can have a strong
association with recurrent pregnancy loss or failure to conceive. Here at
Braverman IVF & Reproductive Immunology
our patients with thyroid abnormalities are carefully evaluated and
are tailored to account for the endocrine immunologic and the thrombophilic
blood clotting components of this disorder.