Hypothyroidism in pregnancy increases ADHD risk in their child

By Mili Jayadeep | Science Editor

Hypothyroidism occurs when there is an underproduction of hormones released from the thyroid gland located in the neck. The hormones produced by this gland play a crucial role in normal metabolic function. A recent investigation shows that during the starting months of pregnancy, hypothyroidism in the mother can hinder the normal development of the babyÔÇÖs brain.

 A large-scale American study conducted on women during the first trimester of their pregnancy reveals findings showing that hypothyroidism in the mother may cause attention deficit hyperactivity disorder (ADHD) in their children. The new study was the first of its kind to study this link and was led by a researcher at an NYU Long Island School of Medicine and was published in the American Journal of Perinatology. Morgan Peltier, an associate Professor in the departments of Clinical Obstetrics, Gynaecology, and Reproductive Medicine at NYU Winthrop Hospital who led the study says,

┬á“Our findings make clear that thyroid health likely has a much larger role in fetal brain development and behavioral disorders like ADHD than we previously understood,”┬á

 The investigation was conducted on a large sample size of children born from mothers with hypothyroidism during pregnancy. These children were followed up to the age of 17 and it was noted that once the foetus reached the second trimester, the hormones released by the mother due to hypothyroidism did not play as significant a role in altering foetal development. It was hypothesised that this was owing to the baby being able to regulate its own hormone production at that stage.

 The study was inclusive of children from a diverse range of ethnicities, hence being more representative of different races. It also used a large group of study participants, unlike similar studies conducted previously. The authors are optimistic about the strength of the study as the long follow-through period enabled the researchers to study the children during schooling and observe cases of ADHD as they developed. The scientists took into consideration medical records of the study participants and factors such as age of pregnancy, ethnic background as well as household incomes, which could affect the results of the study.

 The results showed that mothers diagnosed during the start of their pregnancy or during this first trimester were at a 24% increased risk of having children who would later develop ADHD compared to mothers without hypothyroidism. Also, the ethnic group at the greatest risk of developing ADHD associated with hypothyroidism in their mothers were Hispanics. Hispanic children had a 45% greater risk of developing ADHD compared to a lower risk of 22% in white children.

The study highlighted the need to closely observe children born from women with hypothyroidism during early pregnancy. The study has enough evidence to bring this into clinical practice in order to better manage diagnoses of ADHD as early intervention is beneficial as it would help children succeed in society and school despite their condition.

The future of this research aims to investigate possible association with hypothyroidism and its relation to other neurodevelopmental conditions such as epilepsy, cerebral palsy and speech problems. In addition to this, the environment that the woman is exposed to is crucial to healthy growth and development of the foetus. These researchers also intend to look into factors that increase ADHD risk such as the involvement of environmental toxins.