Pilot Double-Blind Placebo Controlled Trial of Levothyroxine in Pregnant Systemic Lupus Erythematosus (SLE) Patients With Autoimmune Thyroid Disease

Objectives: The investigators hypothesize that levothyroxine decreases miscarriages and preterm birth.

The investigators will compare levothyroxine versus placebo to determine the effects on pregnant women with Autoimmune thyroid disease.

Background:The last two decades have witnessed an explosion of new research documenting the deleterious impact that thyroid disease has on pregnancy and the postpartum period, in relation to miscarriage, preterm delivery , Intelligence quotient (IQ) of the unborn child and health of the mother postpartum . Both subclinical hypothyroidism and thyroid antibody positivity in euthyroid women have been associated with miscarriage and preterm delivery. .Even minor perturbations of thyroid function have been linked to decreased Intelligence Quotients and impaired neurological development of the unborn child. Approximately 5% of all pregnant women have a thyroid disorder (either subclinical or overt hypothyroidism or hyperthyroidism). Intervention in pregnancy with levothyroxine in euthyroid thyroid antibody positive women has been shown in a prospective study, performed in an area of mild iodine deficiency, to significantly decrease the rate of both spontaneous miscarriage and preterm delivery .

SLE has also been documented to negatively impact pregnancy. Women with systemic lupus erythematosus (SLE) have increased rates of miscarriage and preterm delivery, especially in the setting of active Systemic lupus erythematosus and antiphospholipid antibodies . The offspring of women with Systemic lupus erythematosus are at increased risk for heart block and require neonatal intensive care unit care more frequently . Furthermore, pregnant women with Systemic lupus erythematosus (SLE) have increased mortality rates. Women with Systemic lupus erythematosus (SLE) also have increased rates of hypothyroidism and autoimmune thyroid disease (AITD, defined as the presence of thyroid antibodies with or without thyroid dysfunction). In a recent case-control study performed by questionnaire, Yuen et al documented a 21% prevalence of thyroid disease in Systemic lupus erythematosus (SLE) women versus 10% in controls (p=0.02).

Preterm delivery (PTD), defined as birth prior to 37 weeks gestation, is the leading cause of neonatal mortality and morbidity in the United States. Despite a public health effort to decrease the prevalence of Preterm Delivery (PTD) , the prevalence has increased from 11% in 1996 to 12.7% in 2007, with an annual societal cost of over 26 billion dollars. In an attempt to affect the societal impact of preterm delivery, the Surgeon General made decreasing the prevalence of Preterm Delivery to 7.6% a goal of Healthy People 2010. Although risk factors for Preterm Delivery exist, the majority of women have no known risk factors. Recently, both hypothyroidism and autoimmune thyroid disease have also been linked to preterm delivery.