We normally think of hypothyroidism as affecting our own lives. Afterall, the symptoms can be quite severe, ranging from a lack of energy to being overweight and a whole range of other symptoms.
But can it affect our children? We know that hypothyroidism in pregnancy can be dangerous to the child. But have you ever wondered if your hypothyroidism is affecting your children today?
A new study from the Journal of Clinical Endocrinology & Metabolism suggests that a mother’s hypothyroidism affects her children’s personality traits, perhaps even throughout their lives.
The Chinese authors of this study knew that thyroid hormones play an essential role in neurodevelopment and that a pregnant woman’s thyroid hormones affect the neurodevelopment of her children.
Since behavior is partially a consequence of how our neurological systems develop, these researchers were interested in whether expectant mothers’ thyroid hormones could affect their children’s behavior.
They analyzed information already collected by the Ma’ anshan Birth Cohort in China. This included medical data from 1,860 mother-child pairs who visited the Ma’ anshan Maternal and Child Health Hospital.
Pregnant women were recruited once their pregnancies had been confirmed in 2013 and 2014, and their children were followed until the age of four.
The data of specific interest to these researchers were the women’s thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels throughout their pregnancies, together with questionnaires completed by the children’s primary caregiver describing their behavior at age four.
Since pregnant women’s thyroid hormones tend to increase during pregnancy to facilitate the development of their babies, the researchers considered a slightly upward trajectory of all these hormones to be normal.
As such, most of the women displayed a low TSH trajectory and a moderate FT4 trajectory, which the scientists considered normal. This was the group with which they compared the other participants who displayed different trajectories.
Their findings regarding the hypothyroidism trajectory were pretty interesting:
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1. Boys whose mothers had a high TSH trajectory during pregnancy were twice as likely to be withdrawn.
2. Boys whose mothers had a high TSH trajectory were 2.69 times more likely to externalize problems, meaning that they blamed their problems on other things or people and expected other people to solve them.
3. Boys whose mothers had a low FT4 trajectory were 4.17 times more likely to show aggressive behavior. Low FT4 is the strongest indicator of hypothyroidism.
Therefore, hypothyroidism in pregnant women can cause aggression, withdrawal, and the externalization of problems in their male children.
The findings regarding hyperthyroidism were equally interesting but very different.
Women with high FT4 trajectories had children who were 2.22 times more likely to be anxious or depressed by age four.
Interestingly, none of these relationships held for girls.