Postpartum thyroiditis
Encyclopedia
Postpartum thyroiditis is a phenomenon observed following pregnancy
and may involve hyperthyroidism
, hypothyroidism
or the two sequentially. It affects about 5% of all women within a year after giving birth. The first phase is typically hyperthyroidism
. Then, the thyroid
either returns to normal or a woman develops hypothyroidism
. Of those women who experience hypothyroidism associated with postpartum thyroiditis, one in five will develop permanent hypothyroidism requiring life-long treatment.
Postpartum thyroiditis is believed to result from the modifications to the immune system
necessary in pregnancy
, and histologically is a subacute lymphocytic thyroiditis. The process is normally self-limiting, but when conventional antibodies are found there is a high chance of this proceeding to permanent hypothyroidism. Postpartum thyroiditis is a member of the group of thyroiditis conditions known as resolving thyroiditis.
function resumes. Any case with hypothyroid symptoms extending beyond one year postpartum is not considered postpartum thyroiditis .
Women who test positive for thyroid antibodies may be at increased risk of developing symptoms associated with postpartum depression
than women without thyroid antibodies.
Women with type I diabetes mellitus have a threefold increase in the prevalence of postpartum thyroiditis than non-diabetic women in the same region .
Specifically, the immunohistological features of susceptible women are indicated by :
Assessing treatment for the hypothyroid is more complex. Women with symptoms or a very high TSH level, or both, are usually prescribed a course of levothyroxine
. Asymptomatic women with slightly elevated TSH levels who are planning subsequent pregnancies, should consider a course of treatment until completion of the family to avoid possible developmental complications in future children . Otherwise, treatment could be discontinued after 1 year postpartum.
--JennyBrown21 (talk) 19:43, 11 November 2011 (UTC)
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
and may involve hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...
, hypothyroidism
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
or the two sequentially. It affects about 5% of all women within a year after giving birth. The first phase is typically hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...
. Then, the thyroid
Thyroid
The thyroid gland or simply, the thyroid , in vertebrate anatomy, is one of the largest endocrine glands. The thyroid gland is found in the neck, below the thyroid cartilage...
either returns to normal or a woman develops hypothyroidism
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
. Of those women who experience hypothyroidism associated with postpartum thyroiditis, one in five will develop permanent hypothyroidism requiring life-long treatment.
Postpartum thyroiditis is believed to result from the modifications to the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
necessary in pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
, and histologically is a subacute lymphocytic thyroiditis. The process is normally self-limiting, but when conventional antibodies are found there is a high chance of this proceeding to permanent hypothyroidism. Postpartum thyroiditis is a member of the group of thyroiditis conditions known as resolving thyroiditis.
Signs & Symptoms
The initial phase of hyperthyroid symptoms occurs transiently about two to six months postpartum. Typical symptoms include fatigue, irritability, nervousness, palpitations, and heat intolerance. Hormonal disturbances during this phase tend to occur with lower intensity compared with the hypothyroid phase . As a result, the hyperthyroid phase may pass undetected. The second phase of hypothyroid symptoms is also transient and can occur anytime within the three to twelve month period postpartum . Women in this phase experience low energy, poor memory, impaired concentration, carelessness, dry skin, cold intolerance, and general aches and pains. After one year postpartum, euthyroidEuthyroid
Euthyroid is the state of having normal thyroid gland function.Examples of a nonfunctioning thyroid gland may be hypothyroidism, hyperthyroidism, or thyroiditis....
function resumes. Any case with hypothyroid symptoms extending beyond one year postpartum is not considered postpartum thyroiditis .
Women who test positive for thyroid antibodies may be at increased risk of developing symptoms associated with postpartum depression
Postpartum depression
Postpartum depression , also called postnatal depression, is a form of clinical depression which can affect women, and less frequently men, typically after childbirth. Studies report prevalence rates among women from 5% to 25%, but methodological differences among the studies make the actual...
than women without thyroid antibodies.
Prevalence
Worldwide reporting of postpartum thyroiditis cases is highly varied. This variation may be due to methodological discrepancies in assessing women for this condition. Factors such as length of follow-up after delivery, diagnostic criteria, frequency of postpartum blood sampling, and thyroid hormone assay methodology likely contribute to this variation. On average, 5-7% of pregnant women from most iodine-replete populations develop this condition.Women with type I diabetes mellitus have a threefold increase in the prevalence of postpartum thyroiditis than non-diabetic women in the same region .
Etiology
During pregnancy, immunologic suppression occurs which induces tolerance to the presence of the fetus. Without this suppression, the fetus would be rejected causing miscarriage. As a result, following delivery, the immune system rebounds causing levels of thyroids antibodies to rise in susceptible women.Specifically, the immunohistological features of susceptible women are indicated by :
- antibodies to thyroglobulin (TgAb)
- antibodies to thyroid peroxidase (TPOAb)
- increase in TPOAb subclasses IgG1-IgG3
- lymphocyte infiltration and follicle formation within thyroid gland (Hashimoto's thyroiditisHashimoto's thyroiditisHashimoto's thyroiditis or chronic lymphocytic thyroiditis is an autoimmune disease in which the thyroid gland is gradually destroyed by a variety of cell- and antibody-mediated immune processes. It was the first disease to be recognized as an autoimmune disease...
) - T-cell changes (increased CD4:CD8 ratio)
Diagnosis
This condition is commonly undiagnosed by physicians due to either unfamiliarity with the disease, the subtly of symptoms, or the attribution of the symptoms to the stresses of having a newborn. Usual screening begins with assessing the thyroid stimulating hormone (TSH) level. A suppressed TSH could represent the hyperthyroid phase, but warrants further testing to investigate for possible Grave's disease . A normal TSH with persistent symptoms could represent the shift between phases and requires repeat testing 4-6 weeks later; an elevated TSH at this time could indicate the hypothyroid phase .Treatment
For most women, the hyperthyroid phase presents with very mild symptoms or is asypmtomatic; intervention is usually not required. If symptomatic cases require treatment, a short course of beta-blockers would be effective .Assessing treatment for the hypothyroid is more complex. Women with symptoms or a very high TSH level, or both, are usually prescribed a course of levothyroxine
Levothyroxine
Levothyroxine, also L-thyroxine, synthetic T4, or 3,5,3',5'-tetraiodo-L-thyronine, is a synthetic form of thyroxine , used as a hormone replacement for patients with thyroid problems. The natural hormone is chemically in the chiral L-form, as is the pharmaceutical agent...
. Asymptomatic women with slightly elevated TSH levels who are planning subsequent pregnancies, should consider a course of treatment until completion of the family to avoid possible developmental complications in future children . Otherwise, treatment could be discontinued after 1 year postpartum.
--JennyBrown21 (talk) 19:43, 11 November 2011 (UTC)