- University of Cardiff researchers study effect of thyroid hormone replacement drug on pregnant women with mild hypothyroidism.
- If you are hypothyroid and pregnant don't forget to take your thyroid tablets. Thyroid tablets was found to lower the risk of still birth, early cesarean-section and low birth weight in the pregnant women.
- Study lead author declares early detection and intervention important.
The administration of thyroid hormone to
women during pregnancy has been found to reduce the risk of stillbirth,
birth weight as well as lower the risk for early C-section. The study
Dr Peter Taylor was presented at The Endocrinology conference at
About 2 to 3 % of
pregnant women are diagnosed with hypothyroidism
. This is a
condition in which
the hormone is secreted in lower quantities. The thyroid hormone is
the base of the neck and the amount of thyroid hormone that is secreted
critical role in fetal development.
‘Thyroid hormone level important for pregnancy outcomes.’
Thyroid Hormone in Fetal Development
Previous studies have
highlighted the significance of this hormone with fetal development.
Researchers Pemberton HN and colleagues studied the effect of thyroid
levels and fetal brain development. They found that this hormone
signals that were required for the growth and maturation of the neuronal
the absence of which could lead to mental retardation in children.
The most important
aspect of thyroid hormone levels on fetal brain development is the
hormone should be present at the developmental stage to be beneficial.
have shown that the damages caused to the developing fetal cortex and
hippocampus regions are permanent.
Thyroid Hormone Levels and Pregnancy
The thyroid hormone
levels on fetal brain development have been extensively studied,
effect of mild hypothyroidism on pregnancy complications
researched. This study focuses on the effect of the thyroid hormone on
pregnancy outcomes like stillbirth, early C-section and low birth
Researchers from The
University of Cardiff studied the effect of the hormone replacement drug
The study utilized data
from a survey as well as parameters that are usually collected in a
set up. These were combined to find a correlation. In the study, 13,000
who were 12-16 weeks pregnant were analyzed, out of which 518 were found
have mild hypothyroidism. Out of the women with mild
hypothyroidism, 263 did not receive any treatment for their
The pregnancy outcomes
that were studied include length of stay at the hospital, stillbirth
birth weight preterm delivery and the number of early caesarean sections
found that women with mild hypothyroidism and who received levothyroxine
lower risk for early caesarean deliveries and a lower risk for
still born baby. Another interesting angle that was discovered in this
was that women with mild hypothyroidism who were undetected and did not
treatment had a higher risk of delivering a still birth baby when
a woman with normal thyroid hormone function.
The study did
not find any significant association between the level of thyroid
other pregnancy outcomes. Dr. Peter Taylor who is the primary author of
study stated "Our work raises the possibility of providing real benefits
from using a safe, cheap and well established treatment by simply
to the number of pregnant women we treat."
to the benefit gained from this trial, Dr Taylor stressed that the
detection of poor thyroid function and earlier the start of treatment
thyroid replacement drug, the better the outcomes for the mother as well
child. "We should consider universal thyroid screening in pregnancy as
compares favourably in terms of cost-effectiveness with other conditions
we currently screen for," he further added.
Significance of Early Treatment
There are two
sources of thyroid hormone for the developing fetus, one from the mother
one from the fetus itself. However, the fetal hormone is available only
12 weeks of gestation. There is substantial transfer of maternal hormone
the placenta, this is especially significant during the early stages of
development when the fetus hasn't begun secreting its own. Early
mild hypothyroidism will aid in better health of the fetus as well as in
pregnancy outcomes. Types of
Hypothyroidism that Affect Fetal
: Severe hypothyroidism usually leads to
infertility and is
not usually associated with pregnancy. When it does occur, it leads to
the fetus in the womb or even gestational hypertension. Hypothyroidism
mild is an alarming factor in pregnancy as it is usually subclinical and
too late. In some cases it is caused due to an autoimmune disorder
thyroid hormone or could pass the placenta and affect the fetal thyroid
2. Fetal Hypothyroidism:
is a rare congenital condition that leads to poor development of the
thyroid hormone, which leads to poor thyroid hormone levels. The
not affect the growth of the fetus as the hormone is provided by the
the placenta. However, it is important to detect this condition soon
birth as it could lead to a permanent mental retardation called
3. Iodine Deficiency:
Low level of
iodine in the mother leads to hypothyroidism
in the mother as well as the fetus. Iodine deficiency
is the most
preventable cause of mental retardation in children.
hypothyroidism is a silent condition in pregnant women that can lead
to complication in the fetus as well as in pregnancy outcomes. It is
to identify this condition and to take hormone replacement drug to aid
mother and child.
- Thyroid Hormones: Pregnancy and Fetal Development - (http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/thyroid/thyroid_preg.html)
- Transplacental thyroxine and fetal brain development - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC152596/)
- Thyroid hormones and fetal brain development - (https://www.ncbi.nlm.nih.gov/pubmed/16170282)