Gestational Hypothyroidism & Postpartum Thyroiditis

Thoughts and research from one of Tree of Life's wonderful students:

Theresa Blahut, Student Midwife MMCI

Gestational hypothyroidism and postpartum thyroiditis occurs at a much higher rate than one may expect.  Gestational hypothyroidism is a term used to describe women who are hypothyroid while pregnant but did not have a thyroid imbalance prior to pregnancy.  A recent publication in the Journal of Clinical Endocrinology & Metabolism documented that 15.5% of the pregnant women tested had gestational hypothyroidism.  It was also found that women ages 35 to 40 years are nearly twice as likely to suffer from gestational hyperthyroidism as women who are ages 18 to 24 years.  Also, women who weigh more than 275 pounds are 25 times more likely to develop gestational hypothyroidism.

Thyroid disease is common in women of child-bearing age and may affect both mother and baby.  Potentially, gestational hypothyroidism may cause premature delivery or miscarriage and effect the baby's neurological development.  Hypothyroidism symptoms in the mother include; fatigue, lethargy, constipation and feeling cold.

Women should have their thyroid tested before pregnancy and ideally, thyroid testing will become routine in pregnancy.  Pregnant women who are on thyroid hormone should have their blood tested frequently during pregnancy as dosage requirements may change.

Postpartum thyroiditis is a condition with similar pathogenic features as Hashimotos disease were in the immune system attacks the thyroid gland. This disease affects between 5 to 9 percent of postpartum women.  Typically, there is a transient hyperthyroid phase that is followed by a phase of hypothyroidism.  The hyperthyroid phase will not usually require treatment.  The hypothyroid phase should be treated with hormone replacement.

Long term follow up is necessary to access thyroid function and adjust the medication dosage. Nearly all the women with postpartum thyroiditis have positive TPO antibodies.  This marker can be a useful screening test early in pregnancy as 50% of women with these antibodies will develop thyroid dysfunction postpartum.  In addition, some studies have shown an association between postpartum thyroid disorder and depression so that thyroid function should be checked postpartum in women who have significant mood changes.