Maternal Thyroid Autoantibodies Predict Poor Perinatal Outcomes

Abstract

Endocrinology| July 01 2009 Maternal Thyroid Autoantibodies Predict Poor Perinatal Outcomes AAP Grand Rounds (2009) 22 (1): 5. https://doi.org/10.1542/gr.22-1-5 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Maternal Thyroid Autoantibodies Predict Poor Perinatal Outcomes. AAP Grand Rounds July 2009; 22 (1): 5. https://doi.org/10.1542/gr.22-1-5 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: perinatal period, thyroid autoantibodies, thyroid diseases, antibodies Source: Männistö T, Vääräsmäki M, Pouta A, et al. Perinatal outcome of children born to mothers with thyroid dysfunction or antibodies: a prospective population-based cohort study. J Clin Endocrinol Metab. 2009;94(3):772–779; doi:10.1210/jc.2008-1520 Investigators from Finland and the UK prospectively evaluated the effect of maternal thyroid dysfunction and autoimmunity on perinatal outcomes. Data on 9,247 pregnant Finnish women and their singleton births from the Northern Finland Birth Cohort were analyzed. Blood samples from a subset of mothers during the first trimester were analyzed for serum free T4 (fT4), thyroid stimulating hormone (TSH), thyroid-peroxidase antibody (TPO-Ab), and thyroglobulin antibody (TG-Ab). The study participants were divided into four groups based on thyroid studies: 1) clinical hypothyroidism (high TSH, low fT4); 2) subclinical hypothyroidism (high TSH, normal fT4); 3) subclinical hyperthyroidism (low TSH, normal fT4); and 4) clinical hyperthyroidism (low TSH, high fT4). Blood samples were available from 5,805 mothers. Approximately 1% (n=54) had clinical hypothyroidism, 4% (n=224) subclinical hypothyroidism, 4% (n=204) subclinical hyperthyroidism, and 1.5% (n=77) clinical hyperthyroidism. Approximately 5% had TPO-Ab or TG-Ab positivity. Infants born to clinically hyperthyroid mothers were more likely to be large for gestational age (6.6% vs 2.5%) although this effect disappeared after correction for maternal age and parity. Infants born to TPO-Ab positive but not TG-Ab positive mothers were more likely to have low birth weight or be large for gestational age. The adjusted odds ratio of perinatal death among children born to TPO-Ab positive mothers was 3.2 (95% CI, 1.4–7.1) and 2.5 (95% CI, 1.1–5.9) for children born to TG-Ab positive mothers. More than half the deaths among children born to thyroid autoantibody positive mothers occurred in infants born at less than 28 weeks gestation. The authors conclude that positive maternal thyroid autoantibody but not thyroid hormone status is a risk factor for perinatal death. Dr Varma has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device. This large Finnish study sheds new light on the relationship of maternal thyroid disease and perinatal outcomes, an issue that has been addressed in previous studies.1,–3 Prior investigations suggested that thyroid dysfunction is associated with spontaneous abortions, fetal death, premature births, microcephaly, low birth weight, and impaired psychological development.4,5 The strengths of this current study are its large size and relatively complete collection of data on this cohort. The data support the authors’ conclusion that maternal thyroid autoantibodies detected during the first trimester are independently associated with risk for perinatal mortality, most likely through a higher incidence of pre-term delivery. However, the authors also acknowledge that, even with this large cohort, perinatal mortality was a rare event and thus the actual risk may be different from that seen in this study. In addition, because the Finnish population is 99% Caucasian the study needs to be replicated in more ethnic groups before its results are applied to a diverse populace such as that of... You do not currently have access to this content.