In the second and third trimester, this risk is diminished and methimazole is preferred to avoid the risk of liver complications from PTU in the mother.The primary effect on the fetus from transplacental passage of PTU is the production of a mild hypothyroidism when the drug is used close to term. This usually resolves within a few days without treatment. The hypothyroid state may be observed as a goiter in the newborn, and is the result of increased levels of fetal pituitary thyrotropin. The incidence of fetal goiter after PTU treatment in reported cases is approximately 12%. Mechanism of action
Thyroid
PTU inhibits the enzyme thyroperoxidase, which normally acts in thyroid hormone synthesis by oxidizing the anion iodide (I−) to iodine (I0), facilitating iodines addition to tyrosine residues on the hormone precursor thyroglobulin. This is one of the essential steps in the formation of thyroxine (T4).PTU does not inhibit the action of the sodium-dependent iodide transporter located on follicular cells basolateral membranes. Inhibition of this step requires competitive inhibitors, such as perchlorate and thiocyanate. T3/T4 target tissues
PTU also acts by inhibiting the enzyme 5-deiodinase (tetraiodothyronine 5 deiodinase), which converts T4 to the more active form T3. (This is in contrast to methimazole, which shares propylthiouracils central mechanism, but not its peripheral one.) It is important to recognize that these enzymes only work on the conjugated tyrosine molecules of T3 and T4: a completely different enzyme family is responsible for the deiodinase activity of iodized single tyrosine molecules within the thyroid follicular cells.
An obturator hernia is a rare type of hernia of the pelvic floor in which pelvic or abdominal contents protrudes through the obturator foramen. Because of differences in anatomy, it is much more common in women, especially multiparous and older women who have recently lost much weight. The diagnosis is often made intraoperatively after presenting with bowel obstruction. The Howship–Romberg sign is suggestive of an obturator hernia, exacerbated by thigh extension, medial rotation and abduction. It is characterized by lancinating pain in the medial thigh/obturator distribution, extending to the knee; caused by hernia compression of the obturator nerve. References


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