Introduction: The effects of maternal suboptimal gestational thyroid function (SGTF) on age 3 offsprings cognitive function were investigated in the Controlled Antenatal Thyroid Screening (CATS) randomised trial, comparing SGTF mothers who received (SGTF-T), or didnt (SGTF-U), levothyroxine during pregnancy. The analysis was repeated at age 9 in the CATS-II follow-up study, also including children of mothers with normal gestational thyroid function (NGTF). Here we report the long-term effects on anthropometric and cardiometabolic outcomes in both children and mothers assessed at CATS-II.
Methods: Evaluation of 332 mothers aged 41.2±5.3 years (mean±SD) and 326 paired children 9.3±1.0 years after birth: 197 NGTF, 56 SGTF-U, 79 SGTF-T. The BMI was calculated in the whole cohort; in children it was expressed as BMI standard deviation score (BMI-SDS) against UK standards. Subsets also underwent: i) dual-energy x-ray absorptiometry scan of lean/fat mass; ii) Vicorder analysis of systolic/diastolic blood pressure, augmentation index and aortic pulse wave velocity; iii) serum measurement of thyroid function, lipids, insulin and adiponectin. Linear regression was used to analyse the difference between means of the 3 groups (NGTF, SGTF-U, SGTF-T).
Results: Children analysis showed no significant differences between groups in any of the parameters evaluated. Despite baseline (at CATS) maternal BMI was similar among the three groups, at CATS-II SGTF-U mothers had significantly higher BMI, fat mass. triglyceride and insulin levels compared with NGTF and SGTF-T. At CATS-II SGTF-U mothers also had higher TSH levels, since only 24.0% of SGTF-U were started on levothyroxine after CATS, versus 84.5% of SGTF-T (P<0.001) (Table 1).
Conclusions: No impact of levothyroxine supplementation during pregnancy in women with SGTF was observed on childrens cardiometabolic parameters evaluated at age 9. However levothyroxine treatment commenced after screening for SGTF provided significant metabolic benefits among mothers: treated women avoided the sustained long-term increase of BMI, fat mass, triglyceride and insulin levels observed in the untreated group.
|BMI Kg/m2 median (IQR)||25.8 (22.930.0)||28.3 (24.632.6)||25.8 (23.129.8)||0.029|
|Subtotal FAT % mean ± SD||40.2±7.2||42.8±7.2||40.4±7.4||0.017|
|Triglyceride mmol/l median (IQR)||0.90 (0.701.10)||1.01 (0.781.40)||0.80 (0.641.29)||0.041|
|Insulin μIU/ml median (IQR)||5.90 (4.607.80)||6.30 (4.409.15)||5.50 (3.857.15)||0.046|
|TSH mU/l median (IQR)||1.54 (1.122.07)||2.45 (1.433.50)||1.68 (0.892.96)||0.015|
18 - 21 May 2019
European Society of Endocrinology