Wednesday, May 4, 2011
A touching story of an old father, son and a sparrow - Câu chuyện cảm động về người bố già, cậu con trai và con chim sẻ
Thyroid 'risk from pre-eclampsia' Nguy cơ giáp do tiền sản giật
Thyroid 'risk from pre-eclampsia' Nguy cơ giáp do tiền sản giật
Pregnant women with the potentially dangerous condition pre-eclampsia may be more likely to suffer from thyroid problems, research suggests.
Teams from the US and Norway found those with the condition had a raised risk of an under-active thyroid, which can lead to fatigue and depression.
They say women showing signs of pre-eclampsia need thyroid checks as well as standard heart and kidney checks.
The study appears in the British Medical Journal.
The thyroid gland controls the rate at which the body burns energy and makes hormones, which help regulate heart rate, blood pressure and body temperature.
If it is under-active it can lead to a condition known as hypothyroidism, which can produce many symptoms, such as fatigue, weakness and depression, and raise the risk of cardiovascular disease.
Pre-eclampsia is a condition linked to abnormally high blood pressure which, if untreated, can endanger both mother and baby, causing convulsions and damaging the heart and kidneys.
The condition leads to the deaths of 1,000 babies each year in the UK alone.
The cause of pre-eclampsia remains unclear, but the condition has been linked to raised levels of certain proteins during the second half of pregnancy.
Lingering risk
The latest study found women who develop pre-eclampsia during pregnancy have a raised risk of reduced thyroid function while they are pregnant and much later in life.
The US team carried out thyroid function tests on 280 pregnant women, half of whom developed pre-eclampsia.
They found that elevated levels of a hormone released when the thyroid is underactive were twice as common in women who developed pre-eclampsia during pregnancy.
This effect was detected in the latter stages of pregnancy, and mostly suggested a small dip in thyroid function, although two women were diagnosed with hypothyroidism.
The Norway-based team analysed data on more than 7,000 women who gave birth to a first child in the late 1960s, and then had thyroid function tests in the mid-1990s.
They found women who had pre-eclampsia in their first pregnancy were 1.7 times as likely to have signs of an underactive thyroid decades after pregnancy than women who had not had pre-eclampsia.
Those who had pre-eclampsia in both their first and second pregnancies were nearly six times as likely to show signs.
The researchers believe the key may be that pre-eclampsia leads to an elevation in a particular protein in the mother's blood which acts to limit blood supply to the thyroid tissue.
Researcher Dr Richard Levine, of the US National Institute of Child Health and Human Development (NICHD), said: "I do not know if subclinical hypothyroidism poses a risk to a women when pregnant, but it might have health implications for her child since overt hypothyroidism during pregnancy has been linked to lower IQs in the offspring."
Dr Susan Shurin, acting director of NICHD, said: "The findings suggest that the possible development of hypothyroidism is a consideration in patients with a history of pre-eclampsia.
"Reduced thyroid functioning is easy to diagnose when suspected, and inexpensive to treat."
Mr Donald Peebles, a consultant obstetrician at University College Hospital London, said the study suggested that women who had developed pre-eclampsia should be monitored for thyroid problems, but he said the finding would not impact on the treatment of pre-eclampsia itself.
He said: "Pregnancy tends to unmask conditions that may be already underlying, and this may be the case here."
Headaches
Shortness of breath
Blurred or altered vision
Abdominal or shoulder pain
Nausea and vomiting
Confusion
If not treated:
Convulsions
Kidney damage
Call for thyroid screening in pregnancy - Tét sàng lọc tuyến giáp lúc mang thai
Experts are divided on the need for thyroid screening
All pregnant women should be screened for hidden signs of thyroid disease, according to Czech researchers.
A blood test can pick up about a third of mothers-to-be who have no symptoms but will go on to develop full-blown disease after giving birth, they say.
Early detection could have major implications for the health of mothers and babies, they told the European Congress of Endocrinology.
UK midwives say more evidence is needed of the merits of screening.
The study, led by Dr Eliska Potlukova of Charles University in Prague, followed almost 200 women through early pregnancy and beyond.
About a third of these women went on to develop thyroid problems within two years of birth.
Dr Potlukova said tens of thousands of European women who will have thyroid problems could be detected earlier, which has major implications for the health of mother and baby.
She told the BBC: "If a woman of childbearing age is thinking of getting pregnant she should visit her GP or gynaecologist to have her blood tested for thyroid function and thyroid auto-immunity.
"Every young women should be sure that her thyroid gland works fine before she gets pregnant."
Screening all pregnant women for thyroid problems has been discussed in many countries.
In the US, universal screening was rejected in 2006 on the grounds of a lack of evidence that it would improve outcomes for mothers and babies.
Most countries, including the UK, recommend screening only high-risk women who have a family history of thyroid disease or have suffered thyroid problems in the past.
Sue Jacobs, a midwife teacher at the Royal College of Midwives, said more evidence was needed for the benefits of universal screening.
She said: "In the UK we have a comprehensive programme of antenatal care from as early as possible in pregnancy.
"This gives us a good baseline to monitor women throughout pregnancy and immediately after pregnancy."
The research was "a step in the right direction", she added, but needed to be repeated on a larger scale.
Thyroid disease in pregnancy
- Thyroid disease happens when the thyroid gland produces too much (hyper) or too little (hypo) thyroid hormone
- Common causes of hyperthyroidism include Graves' Disease - where the body's immune system turns on itself
- Another auto-immune disorder - Hashimoto's thyroiditis - which causes hypothyroidism - is also common in pregnancy
- Uncontrolled thyroid conditions can cause risks to the mother and baby