Successful Outcome of Pregnancy in a Thyroidectomized-Parathyroidectomized Young Woman Affected by Severe Hypothyroidism

Abstract

Severe hypothyroidism was discovered in a young woman in her 29th week of pregnancy. Previously, at the age of 12 years, she had undergone thyroid surgery for Graves' disease that resulted in persistent hypothyroidism and hypoparathyroidism. After surgical excision, the patient started levothyroxine replacement therapy and had regular control of thyroid function with normal findings throughout the years. The dose of levothyroxine had not been adjusted when the pregnancy started, and at the 29th week of gestation the patient had a thyrotropin (TSH) of 72.4 microU/mL. Ultrasound studies were performed in order to monitor fetal development. The fetal parameters analyzed before the adjustment of levothyroxine therapy showed growth retardation of various degrees. All analyzed fetal parameters (biparietal diameter, cranial and abdominal circumference, humerus and femur length) improved during the last 6 weeks of gestation, showing a good correlation with the newly achieved euthyroid state of the mother. The infant was clinically euthyroid at birth and was found normal at all evaluations of the neonatal hypothyroidism screening program (1, 5, 30 days).

Effects of increased thyroxine dosage pre-conception on thyroid function during early pregnancy

“…However, lack of statistical significance may be at least in part dependent upon the small sample size of our study group as well as the different prevalence of thyroidectomized vs Hashimoto's-affected patients (27.3% and 57.1%) in groups I and II respectively. Such results should not encourage delaying the first post-conception hormone evaluation; this should always be performed as soon as possible since previous studies have demonstrated that even patients under a suppressive L-T4 regimen before pregnancy may turn severely hypothyroid in later stages of gestation (22,23). In other words, women under partially suppressive therapy, even when euthyroid at the first post-conception hormonal evaluation, must be re-evaluated in later stages of pregnancy.…”