Low maternal free thyroxine concentrations during early pregnancy are associated with impaired psychomotor development in infancy

Abstract

Low maternal plasma fT4 concentrations during early pregnancy may be an important risk factor for impaired infant development.

Behavioral deficits associated with fetal alcohol exposure are reversed by prenatal thyroid hormone treatment: a role for maternal thyroid hormone deficiency in FAE

“…[22][23][24] In humans, consequences of maternal thyroid hormone deficiency depend on the level of the deficiency and their specific developmental timing (reviewed in Zoeller and Rovet 25 ). Similarly, in the rat, maternal thyroid hormones play a role in fetal thyroid economy, and prenatal thyroid hormone insufficiency affects adult behavior leading to learning deficits and hyperactivity.…”

Treatment of Subclinical Hypothyroidism or Hypothyroxinemia in Pregnancy

“…[1][2][3][4][5] In 1999, interest in undiagnosed maternal thyroid dysfunction was heightened by studies suggesting an association between subclinical thyroid hypofunction and impaired fetal neuropsychological development. 6,7 In one report, children of women whose serum thyrotropin levels during pregnancy were greater than the 98th percentile had a lower IQ than children of matched controls who had a normal thyrotropin level. 6 In another study, children whose mothers had a serum free thyroxine (T 4 ) level of less than the 10th percentile in early pregnancy had impaired psychomotor development at 10 months of age, as compared with children whose mothers had a higher free T 4 level.…”

“…6 In another study, children whose mothers had a serum free thyroxine (T 4 ) level of less than the 10th percentile in early pregnancy had impaired psychomotor development at 10 months of age, as compared with children whose mothers had a higher free T 4 level. 7 Subclinical hypothyroidism has also been associated with increased risks of preterm birth, placental abruption, admission to the intensive care nursery (or neonatal intensive care unit), and other adverse pregnancy outcomes that could explain neurodevelopmental delay. [8][9][10][11] However, the risks of these adverse outcomes are not increased among women with hypothyroxinemia in pregnancy.…”

11 Hypothyroidism in Pregnancy

“…During pregnancy, TSH levels higher than 4.5 mIU/l have been related to impaired fetal neurological and psychomotor development and an increased risk of premature labor, preeclampsia, and abruption placenta [53,59] Although the majority of large-scale, well-designed studies depict a consistent adverse impact from mild to moderate to moderate maternel hypothyroidism, some studies are contradictory [49,62] …”

“…Many studies [4,59] have conclusively proved that children born to mothers with hypothyroidism had a significantly increased risk of impairment in IQ scores, neuropsychological developmental indices and learning abilities. This risk applies to children born not only of untreated women, but also women with suboptimal supplementation.…”