The thyroid in pregnancy
Fetal thyroxine is wholly obtained from maternal sources in early pregnancy since the fetal thyroid gland only becomes functional in the second trimester of gestation. As thyroxine is essential for fetal neurodevelopment it is critical that maternal delivery of thyroxine to the fetus is ensured early in gestation. In pregnancy, iodide losses through the urine and the feto-placental unit contribute to a state of relative iodine deficiency. Thus, pregnant women require additional iodine intake. A daily iodine intake of 250 µg is recommended in pregnancy but this is not always achieved even in iodine sufficient parts of the world.Thyroid hormone concentrations in blood are increased in pregnancy, partly due to the high levels of estrogen and due to the weak thyroid stimulating effects of human chorionic gonadotropin (hCG) that acts like TSH. Thyroxine (T4) levels rise from about 6–12 weeks, and peak by mid-gestation; reverse changes are seen with TSH. Gestation specific reference ranges for thyroid function tests are not widely in use although many centres are now preparing them. Hypothyroidism
Clinical evaluation
Hypothyroidism is common in pregnancy with an estimated prevalence of 2-3% and 0.3-0.5% for subclinical and overt hypothyroidism respectively. Endemic iodine deficiency accounts for most hypothyroidism in pregnant women worldwide while chronic autoimmune thyroiditis is the most common cause of hypothyroidism in iodine sufficient parts of the world. The presentation of hypothyroidism in pregnancy is not always classical and may sometimes be difficult to distinguish from the symptoms of normal pregnancy.
Depersonalization can consist of a detachment within the self, regarding ones mind or body, or being a detached observer of oneself. Subjects feel they have changed and that the world has become vague, dreamlike, less real, lacking in significance or being outside reality while looking in. It can be described as feeling like one is on “autopilot” and that the persons sense of individuality or selfhood has been hindered or suppressed.Chronic depersonalization refers to depersonalization/derealization disorder, which is classified by the DSM-5 as a dissociative disorder, based on the findings that depersonalization and derealization are prevalent in other dissociative disorders including dissociative identity disorder.Though degrees of depersonalization and derealization can happen to anyone who is subject to temporary anxiety or stress, chronic depersonalization is more related to individuals who have experienced a severe trauma or prolonged stress/anxiety. Depersonalization-derealization is the single most important symptom in the spectrum of dissociative disorders, including dissociative identity disorder and "dissociative disorder not otherwise specified" (DD-NOS). It is also a prominent symptom in some other non-dissociative disorders, such as anxiety disorders, clinical depression, bipolar disorder, schizophrenia, schizoid personality disorder, hypothyroidism or endocrine disorders, schizotypal personality disorder, borderline personality disorder, obsessive–compulsive disorder, migraines, and sleep deprivation; it can also be a symptom of some types of neurological seizure. In social psychology, and in particular self-categorization theory, the term depersonalization has a different meaning and refers to "the stereotypical perception of the self as an example of some defining social category".