Thyroiditis Postpartum
Postpartum thyroiditis is an autoimmune disorder that affects the maternal thyroid within the first year after delivery . It is associated with the presence of circulating anti-thyroid antibodies (anti-thyroperoxidase and/or anti-thyroglobulin antibodies) and is caused by the sudden reactivation of the immune system after nine months of quiescence.
During pregnancy, the immune system becomes more tolerant to prevent some antibodies from damaging the fetus which half took from the father and therefore half is “unknown” to the mother’s immune system.
Postpartum thyroiditis has an approximate prevalence of 8.1% and develops in 33-50% of women who test positive for thyroid antibodies in the first trimester of pregnancy.
They can be women with normal thyroid function or women already suffering from hypothyroidism and being treated with hormone replacement therapy (thyroxine).
It has a prevalence of 25% in patients with autoimmune diabetes mellitus or chronic viral hepatitis, 14% in patients with SLE, 44% in patients with a history of Basedow’s disease.
Times of thyroiditis
It usually occurs between 2 and 6 months after delivery and presents with a phase of thyrotoxicosis , i.e. excess of thyroid hormones, due to the partial destruction of the gland by autoantibodies with consequent release into circulation of thyroid hormones which had accumulated in the thyroid follicles and ready to use.
The thyrotoxicosis phase has a short duration , usually from 1 to 6 weeks, and is accompanied by mild symptoms which can be: irritability, heat intolerance, tiredness and palpitations. They are also difficult to distinguish from the physiological disorders that a mother who takes care of a 3 month old baby can have! In this phase it is not necessary to take antithyroid drugs also because they are ineffective.
Then follows a phase of hypothyroidism , i.e. lack of thyroid hormones, lasting from 2 to 6 weeks which is often the most felt by mothers. Symptoms include intolerance to cold, dry skin, lack of energy, constipation, poor concentration, headache, body aches . After 6 weeks the thyroid function returns to normal so it is sufficient to check the tests every 2 months until the complete resolution of the picture without having to take any therapy.
Permanent hypothyroidism
It should be remembered that 20 to 60% of women who have had postpartum thyroiditis will develop permanent hypothyroidism in the following 10 years, so thyroid function tests should be checked once a year. Those who already had hypothyroidism before pregnancy will return to this condition. On the other hand, 0.5% will develop hyperthyroidism.
It has been shown that pre-treatment with thyroxine in pregnant women with positive anti-thyroid antibodies unfortunately does not prevent postpartum thyroiditis.
A dutiful mention should also be made of the correlation between postpartum thyroiditis and postpartum depression . There are some scientific studies that have shown a link between these two pathological conditions but we are awaiting further confirmatory studies.
For this reason it would be advisable to check the thyroid function of women affected by this depressive syndrome because it could modify the therapeutic approach.
Kathryn Barlow is an OB/GYN doctor, which is the medical specialty that deals with the care of women's reproductive health, including pregnancy and childbirth.
Obstetricians provide care to women during pregnancy, labor, and delivery, while gynecologists focus on the health of the female reproductive system, including the ovaries, uterus, vagina, and breasts. OB/GYN doctors are trained to provide medical and surgical care for a wide range of conditions related to women's reproductive health.