Sex-specific Effect of Maternal Thyroid Hormone Trajectories on Preschoolers’ Behavioral Development: A Birth Cohort Study

Abstract

Context Maternal thyroid hormone trajectories are better predictor of offspring’s neurodevelopment than hormone levels in single trimester of pregnancy. Programming effect of uterine hormonal environment on offspring’s health is usually sex-specific. Objective To examine the sex-specific effect of thyroid hormone trajectories on preschoolers’ behavioral development. Design Based on Ma’ anshan Birth Cohort (MABC) in China, pregnant women were recruited at their first antenatal checkup from May 2013 to September 2014. Setting Ma’ anshan Maternal and Child Health Hospital in China. Patients or Other Participants 1860 mother-child pairs were included in the analysis. Children were followed up at age of 4. Main Outcome Measures Maternal thyroid hormones (TSH, FT4) and TPOAb in the first, second and third trimesters of pregnancy were retrospectively assayed. Preschoolers’ behavioral development was assessed by Achenbach Child Behavior Checklist (CBCL/1.5~5). Results Maternal TSH and FT4 levels were respectively fitted into high, moderate and low trajectories. In boys, maternal high TSH trajectory was related to withdrawn (OR = 2.01, 95% CI: 1.16, 3.50) and externalizing problems (OR = 2.69, 95% CI: 1.22, 5.92), and moderate TSH trajectory was associated with aggressive behavior (OR = 3.76, 95% CI: 1.16, 12.23). Maternal high FT4 trajectory was associated with anxious/depressed (OR = 2.22, 95% CI: 1.08, 4.56) and total problems (OR = 1.74, 95% CI: 1.13, 2.66), and low FT4 trajectory was associated with aggressive behavior (OR = 4.17, 95% CI: 1.22, 14.24). Conclusions Maternal thyroid hormone trajectories impact preschool boys’ behavioral development.

Iodine Status Modifies the Association between Fluoride Exposure in Pregnancy and Preschool Boys’ Intelligence

“…Given that the thyroid gland expresses estrogen and androgen receptors, boys and girls may respond differently to thyroid hormone insufficiency [ 61 , 62 , 63 ]. One study, for example, found that maternal trajectories of thyroid hormones were associated with preschool boys’ behavioural development but not girls’ [ 64 ]. Taken together, these findings indicate that future investigations of fluoride’s neurotoxicity should examine the roles of iodine intake and child sex, and whether thyroid hormones mediate the pathway for fluoride and iodine’s effects on boys’ IQ.…”

Nationwide-free preconception care strategy: Experience from China

“…In addition to hyperglycemia, abnormal thyroid function is more common during the preconception period. Maternal hypothyroidism is related to preterm birth and impaired neurodevelopmental function (78)(79)(80)(81)(82). Sufficient thyroid hormone levels are essential for fetal growth, especially brain development, and timely medication should be initiated and continuously monitored during pregnancy.…”

Thyroid function test abnormalities‐isolated TPOAb+, SCH and hypothyroxinemia and preschool children's neurodevelopment

“…Meanwhile, low FT 4 trajectories were associated with aggression in males. 12 Cognition, emotion and behaviour are three critical domains in evaluating offspring's neurodevelopment. Executive function is one of the high-level cognitive functions required for individuals to set goals, make plans and implement actions effectively.…”

“…Findings from the Ma'anshan birth cohort in China showed that among males, high maternal TSH trajectories were associated with withdrawal and externalizing problems and moderate TSH trajectories were associated with aggression. Meanwhile, low FT 4 trajectories were associated with aggression in males 12 . Cognition, emotion and behaviour are three critical domains in evaluating offspring's neurodevelopment.…”