A Narrative Review on the Effect of Maternal Hypothyroidism on Fetal Development

Discover effective migraine prevention and treatment strategies, including lifestyle changes, medications, and natural remedies, to empower your migraine management journey. Prior to your consultation, it may be helpful to gather relevant information, such as your medical history, previous thyroid function test results, and any current medications or supplements you are taking. This information will assist your healthcare provider in making an informed decision regarding Synthroid use during pregnancy. Before starting or adjusting Synthroid treatment during pregnancy, it is vital to consult with a healthcare provider who specializes in managing thyroid disorders in pregnancy. Thyroxine, the hormone produced by the thyroid gland, is responsible for regulating the body’s metabolism.

WHAT ARE THE SIGNS AND SYMPTOMS OF CONGENITAL HYPOTHYROIDISM?

Untreated hypothyroidism may increase the risk of miscarriage, stillbirth, and complications such as preeclampsia, gestational diabetes, and preterm birth. On the other hand, uncontrolled hyperthyroidism can also pose risks to the pregnancy, including preterm birth and low birth weight. Pregnancy is a time of significant hormonal changes, and the thyroid gland plays a crucial role in supporting the healthy development of the fetus. When a pregnant woman has hypothyroidism, it can lead to complications such as preeclampsia, gestational diabetes, and preterm birth.

Potential Impact of Thyroid Disorders on Pregnancy

This is a brief overview of what is known and unknown regarding thyroid disease and its impact on maternal, fetal, and pregnancy health. Proper management of thyroid disorders during pregnancy can help reduce the risk of complications. Maintaining stable thyroid hormone levels can lower the risk of miscarriage, preterm birth, and fetal growth restriction. Thyroid disorders during pregnancy can have significant implications for both maternal and fetal health.

Congenital Hypothyroidism FAQs

• Hypothyroidism is diagnosed based on a low free T4 or total T4 and high TSH (except for rare cases of central hypothyroidism where TSH will also be low).
• Continuous variables were compared among the 3 groups by using Kruskal–Wallis H test, categorical variables were presented as the frequency (percentage) and compared by using the Chi-square test or Fisher exact test among the 3 groups.
• It is a very well known fact that thyroid diseases during pregnancy are related to maternal and fetal complications.
• Hypothyroidism can occur due to various factors, including autoimmune diseases, radiation therapy, or surgical removal of the thyroid gland.

It is accompanied by hormonal and metabolic changes within the body, which may result in numerous pathophysiological processes and can have a tendency to pose severe outcomes if left untreated 1,2. In pregnancy, the thyroid gland function is observed by a T4 surge at the 12th week which gradually declines. So, diagnosing hypothyroidism during pregnancy is challenging due to variations in thyroid hormonelevels in the blood 4,5. During pregnancy, some factors are responsible for lowering the levels of these hormones in the blood. Depending on the levels of these hormones, the condition can be classified as clinical hypothyroidism, subclinical hypothyroidism, and isolated hypothyroxinaemia 3,6. Subclinical hypothyroidism (SCH) is a condition where there is an elevation of TSH concentration levels with normal levels of thyroxine (T4) hormone in blood serum.

Synthroid is used to manage hypothyroidism during pregnancy to ensure that the thyroid hormone levels remain within the optimal range. For many babies, thyroid hormone replacement therapy will be needed for their entire life. With proper treatment, these children can lead healthy and happy lives, with normal growth and development, and no restrictions as far as activities. For some babies, thyroid hormone deficiency is transient, with treatment required for several months to a few years. In cases where congenital hypothyroidism is thought to be temporary, the baby’s doctor (endocrinologist) may recommend a trial off levothyroxine treatment after age 3 years (after the time of critical brain development).

Women with hypothyroidism who discontinue or do not receive treatment during pregnancy may be at a higher risk of complications. Decisions regarding Synthroid use should be made in consultation with a healthcare provider, taking into account individual circumstances and the potential benefits for both the mother and the baby. Similarly, history and physical examination in pregnant women with thyrotoxicosis are indistinguishable from hyperthyroidism in non-pregnant adults.

• Reports of hypocalcemia, respiratory distress, down syndrome, cardiovascular abnormalities, and urogenital malformations have also been observed 39.
• As a result, the measures used to assess hypothyroidism throughout pregnancy vary depending on the trimester and the remainder of the pregnancy 2,26.
• Since that time, numerous studies with rats, sheep and humans have reinforced this concept, usually by study of the effects of fetal and/or maternal thyroid deficiency.
• It seems clear that there is a great deal more to learn about the molecular mechanisms by which thyroid hormones support normal development of the brain.
• Hypothyroidism during pregnancy is a significant threat not only to the mother but also to her infant.

By prescribing Synthroid, healthcare providers aim to maintain stable thyroid hormone levels in pregnant women, reducing the risk of these complications and promoting a healthy pregnancy. Thyroid disorders, such as hypothyroidism, are relatively common, affecting about 2-3% of pregnant women. If left untreated, these conditions can have adverse effects on both the mother and the baby.

Neonates Small for Gestational Age (SGA) and thyroid function

Pregnancy-induced physiological changes, including increased thyroid hormone production and iodine requirements, can obscure the diagnosis and management of thyroid dysfunction. If left untreated, these conditions increase the risk synthroid allergy of complications such as preeclampsia, preterm labor, low birth weight, and cognitive impairments in the child. Early recognition and appropriate treatment of thyroid disease are essential to mitigate these risks and promote positive pregnancy outcomes. Timely treatment of thyroid disease during pregnancy is important in preventing adverse maternal and fetal outcomes. Thyroid abnormalities are very often subclinical in nature and not easily recognized without specific screening programs. Even mild maternal thyroid hormone deficiency may lead to neurodevelopment complications in the fetus.

There is clear evidence of adverse pregnancy outcomes in cases of untreated overt hypothyroidism and hyperthyroidism in pregnant women. Maternal thyroid hormones are known to be crucial for maintaining a normal fetal growth and development, especially in the first trimester when the fetus is entirely dependent on the transplacental transport of maternal thyroid hormones 1, 2. During the past decades, the impact of maternal thyroid diseases on maternal and fetal health has gained increasing attention. Overt thyroid dysfunctions during pregnancy are related to fetal and maternal complications, and even cause children neurodevelopment disorders in the later life 3. Interest on the relationship between prematurity and endocrine diseases is rising, seen the increased incidence of preterm birth and the better survival rate compared to the previous decades. The development of endocrine disorders in offsprings is influenced not only by the gestational age at birth and the consequent duration of hospitalization, but also by pregnancy factors.

This collaborative approach facilitates comprehensive care, ensures timely interventions, and supports maternal and fetal health through coordinated diagnosis, treatment, and ongoing monitoring efforts. When thyroid hormone deficiency is detected at birth it is called “congenital hypothyroidism”. Babies with congenital hypothyroidism are born with an underactive or absent thyroid gland. Because thyroid hormone plays such an important role in brain development and growth, all babies born in the United States, Canada and other developed countries undergo a screening test to check thyroid function shortly after birth.