Impact of levothyroxine therapy for maternal subclinical and overt hypothyroidism on early child neurodevelopment: A prospective cohort study.

OBJECTIVE

Treatment indication of maternal subclinical hypothyroidism (SCH) is undetermined, despite the wide administration of levothyroxine for maternal overt hypothyroidism (OH). This study aimed to evaluate the therapeutic effect of levothyroxine for maternal SCH and OH in real-world practice, with a focus on early child neurodevelopment.

DESIGN

Prospective cohort study.

PATIENTS AND MEASUREMENTS

Pregnant women diagnosed with SCH at the first antenatal visit were enroled and compared to those diagnosed with OH. Thyroid follow-ups were conducted during pregnancy. Early child neurodevelopment was assessed using the Gesell Development Diagnosis Scale (GDDS) at 1, 3, 6, 12 and 24 months of age.

RESULTS

From January 2012 to December 2013, a total of 442 pregnant women were included in final analysis, among whom 194 and 248 were assigned to the SCH and OH groups, respectively. The percentage of levothyroxine therapy at the first antenatal visit was significantly lower in the SCH group than that in the OH group (91.24% vs. 97.58%, p < .01), with a similar treatment rate at delivery (99.4% vs. 100%, p > .05). Notably, GDDS scores were lower in the SCH group than those in the OH group at 6 months to 2 years of age, which was confirmed by subgroup analyses and sensitivity analyses.

CONCLUSIONS

Children born with maternal SCH demonstrated slightly lower neuropsychological scores at 6 months to 2 years of age compared to those with maternal OH in the clinical practice. The therapeutic effect of maternal SCH on the child neurodevelopment requires further exploration.