Treatment of women with antibodies to the thyroid gland, but the normal functioning of the thyroid gland with a medicine called levothyroxine does not increase the likelihood of bringing a living baby, according to a new study by the University of Birmingham.
A study conducted by researchers from the Institute of Metabolism and Systems Research, the Clinical Studies Department in Birmingham, the Institute for Applied Health Research and the Tommy's Center for the Exploration of Abortion at the University of Birmingham, today (March 23rd) New England Journal of Medicine. The research was funded by the MRC and the National Institute for Health Research (NIHR), and today it was also presented at the ENDO 2019, the annual meeting of the Endocrine Society in New Orleans, USA.
Spontaneous spontaneous abortion occurs in one of five women who are resting, making it one of the most common complications of pregnancy. Previous research revealed a strong link between the presence of antibodies with thyroid peroxidase and spontaneous abortion. However, it was not clear from previous evidence that treatment of women with normal thyroid function and antibodies of thyroid peroxidase with levothyroxine would improve the level of life at birth.
The Birmingham University has now run the largest such study to investigate whether treatment with levothyroxine would increase the level of live-born children at or after the 34th week of pregnancy among women who have antibodies to the thyroid gland, as well as the history of spontaneous abortion or reduced fertility.
Chief researcher dr. Rima Dhillon-Smith, an academic clinical lecturer at the University of Birmingham, said: "Our study showed that treatment with levothyroxine started before pregnancy, in women with normal thyroid function and antibodies with thyroid peroxidase that in the past had an abortion or Infertility does not improve the possibilities of life.
"We were surprised at the results of our study, as previous small studies have shown that treatment with Levotiroxine can be beneficial in women with thyroid antibodies."
The authors conducted a study of 940 women in 49 United Kingdom hospitals with normal thyroid function aged 16 to 41 years old, which were positive for antibodies against thyroid peroxidase; In the past, they had spontaneous abortion or infertility and tried to conceive naturally or through fertilization.
The study, which was carried out between 2011 and 2017, showed that 470 women received 50mcg of levothyroxine per day and 470 women received a daily placebo. The participants started taking the medicine before they rested and continued until the end of the pregnancy.
The results in both groups were similar: 266 out of 470 (56.6%) of women receiving Levothyroxine and 274 of the 470 (58.3%) women who received placebo were pregnant; 176 women (37.4%) who took Levothyroxine and 178 (37.9%) who took placebo had live births.
Dr. Rima Dhillon-Smith added: "Thyroid peroxidase antibodies are found in blood in approximately one in 10 women who have normal thyroid function and are associated with an increased risk of spontaneous abortion and premature birth.
"International guidelines currently recommend taking levothyroxine treatment into women with thyroid antibodies, since it is assumed that there is a minimal chance of injury and that the chance of life can be increased."
"Since our study was large and high quality, we can now believe that Levotiroxin does not improve the performance of pregnancy in women with antibodies to the thyroid gland and the normal thyroid function, so they should not be recommended or used in clinical practice. unnecessary medicine for women who do not need it. "
Dr. Kristien Boelaert, also a university in Birmingham, said: "Our trial finally answered an important clinical issue.
"In a recent study in the United Kingdom's fertility clinic, almost 40% said they used Levotiroxin routinely in women with thyroid peroxidase antibodies to reduce spontaneous abortion and premature birth.
"We are now asking ourselves whether testing for antibodies to thyroid peroxidase should be performed at all in women with infertility or previous spontaneous abortions.
"While testing antibodies to thyroid peroxidase can increase the future risk of thyroid disease progression, our study has shown that treatment with levothyroxine does not improve the results of pregnancy and can only lead to patients' anxiety and unnecessary healthcare costs.
"We hope that national and international guidelines will be updated to remove current recommendations that recommend the treatment of levothyroxine in these women.
"We also hope that the current practice of routine testing of antibodies to thyroid peroxidases in high-risk populations, such as women with spontaneous abortion and reduced fertility, is reconsidered."