Antenatal Thyroid Screening and Childhood Cognitive Function

There is a well-known controversy among scientific societies regarding the recommendation to screen for thyroid dysfunction (TD) during pregnancy. Although several studies have shown an association between maternal subclinical hypothyroidism and/or hypothyroxinemia with obstetric problems and/or neurocognitive impairment in the offspring, there is only limited evidence on the possible positive effects of thyroxine (T 4 ) treatment in such cases. Despite the scarcity of this evidence, there is a widespread agreement among clinicians on the need for treatment of clinical hypothyroidism during pregnancy and the risks that could arise due to therapeutic abstention. As maternal TD is a quite prevalent condition, easily diagnosed and for which an effective and safe treatment is available, some scientific societies have proposed to assess thyroid function during the first trimester of pregnancy and ideally before week 10 of gestational age. Given the physiologic changes of thyroid function during pregnancy, hormone assessment should be performed using trimester-specific reference values ideally based on locally generated data as geographic variations have been detected. Screening of TD should be based on an initial determination of TSH performed early during the first trimester and only if abnormal should it be followed by either a free or total T 4 measurement. Furthermore, adequate iodine supplementation during pregnancy is critical and if feasible it should be initiated before the woman attempts to conceive.

Section: Arguments Against Universal Screeningmentioning

confidence: 82%

Section: Obstetric Complications Associated With Td "mentioning

confidence: 99%

CONTROVERSIES IN ENDOCRINOLOGY: On the need for universal thyroid screening in pregnant women

Vila

Velasco

González

et al. 2014

“…Although no single factor during intrauterine development leads to psychiatric disorders in children, maternal thyroid hormone plays a major role in foetal brain development and is therefore implicated in the development of a range of offspring behavioural and psychiatric problems (16). This is supported by several research findings suggesting associations between early pregnancy thyroid disorders and cognitive development of offspring (6,17,18,19,20,21,22,23,24). There are however fewer studies investigating the potential relationship between maternal thyroid disorders during pregnancy and behavioural and psychiatric disorders in offspring at different ages, and no systematic reviews on the subject.…”

Section: Introductionmentioning

confidence: 90%

MECHANISMS IN ENDOCRINOLOGY: Maternal thyroid dysfunction during pregnancy and behavioural and psychiatric disorders of children: a systematic review

Fetene

Betts

Alati

2017

Background: Maternal thyroid dysfunction during pregnancy may lead to persistent neurodevelopmental disorders in the offspring appearing in later life. This study aimed to review the available evidence concerning the relationship between maternal thyroid status during pregnancy and offspring behavioural and psychiatric disorders. Methods: Systematic electronic database searches were conducted using PubMed, Embase, PsycNET, Scopus, Google Scholar and Cochrane library. Studies including gestational thyroid dysfunction as the exposure and offspring behavioural and psychiatric disorders as the outcome were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed and, after thorough screening by two independent reviewers, 13 articles remained eligible for inclusion in this study. Results: Indicators of maternal thyroid dysfunction, including low and high thyroid hormone level and autoimmune thyroiditis, during early pregnancy, were found to be associated with several offspring behavioural and psychiatric disorders such as attention deficit hyperactivity disorder (ADHD), autism, pervasive developmental problems, externalising behaviour, in addition to epilepsy and seizure. The majority of associations were found with low maternal thyroid hormone level. Conclusion: Maternal thyroid function during pregnancy, particularly hypothyroidism, is associated with behavioural and psychiatric disorders in children. Further studies are needed with a capacity to adjust for a fuller range of confounding factors.

“…Published data on the prevalence of thyroid disease in pregnant women have been based on results of thyroid function tests and/or registration of hospital diagnosis and treatment. Studies with biochemical measurement of thyroid function have used stored serum samples collected as a part of routine prenatal programs (15,16), serum samples collected from women enrolled in a pregnancy cohort (17) or serum samples from women enrolled in a randomized trial (18). In such studies, the prevalence of disease depends on the biochemical definition of thyroid disease as well as the gestational week of sampling.…”

Section: Prevalence Of Thyroid Disease In Pregnancymentioning

confidence: 99%

Maternal thyroid disease in the Danish National Birth Cohort: prevalence and risk factors

Andersen

Olsen

Laurberg

2016

Objective: Thyroid disorders are common in women of reproductive age, but the exact burden of disease before, during and after a pregnancy is not clear. We describe the prevalence of thyroid disease in women enrolled in the Danish National Birth Cohort (DNBC) and investigate some of its risk factors. Design: Population-based study within the DNBC, which included 101 032 pregnancies (1997)(1998)(1999)(2000)(2001)(2002)(2003). Methods: We studied women enrolled in the DNBC who gave birth to a live-born child. Information on maternal thyroid disease (hyperthyroidism, hypothyroidism, benign goiter/nodules, thyroid cancer, and other) before, during and up to 5 years after the woman's first pregnancy in the cohort was obtained from self-report (telephone interview in median gestational week 17) and from nationwide registers on hospital diagnosis of thyroid disease/thyroid surgery (from 1977) and prescriptions of thyroid drugs (from 1995). Results: Of the 77 445 women studied, 3018 (3.9%) were identified with an onset of thyroid disease before (2.0%), during (0.1%) or in the 5-year period after the pregnancy (1.8%). During the pregnancy, 153 (0.2%) women received antithyroid drugs and 365 (0.5%) received thyroid hormone for hypothyroidism (83 after previous hyperthyroidism, 42 after previous surgery for benign goiter/nodules or thyroid cancer). Significant risk factors for maternal thyroid disease were age, parity, origin, iodine intake, smoking, alcohol, and BMI. Conclusions: Around 4% of Danish pregnant women had either a history of thyroid disease or thyroid disease during pregnancy or were diagnosed with thyroid disease for the first-time in the years following a pregnancy. The spectrum of thyroid disease was influenced by demographic and environmental factors.