1. The Prevalence of Thyroid Dysfunction and Autoimmunity in Women With History of Miscarriage or Subfertility
- Author
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Rachel Small, Lee J Middleton, Davor Jurkovic, Yacoub Khalaf, Arri Coomarasamy, Khashia Mulbagal, Andrew Sizer, Martyn Underwood, Pratima Gupta, Mark D. Kilby, Samantha Farrell-Carver, Justin Chu, Kristien Boelaert, Ayman Ewies, Natalie Nunes, Rina Agrawal, Raj Rai, Lynne Robinson, Shiao Chan, Aurelio Tobias, Kalsang Bhatia, Edmond Edi-Osagie, Paul P. Smith, Siobhan Quenby, Rima K Dhillon-Smith, Jane P Daniels, Caroline Overton, Kirandeep K Sunner, Jackie Ross, Ruth Bender-Atik, Tarek Ghobara, Shakila Thangaratinam, Krystyna Baker, and Nick Raine-Fenning
- Subjects
endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Thyrotropin ,Thyroid Function Tests ,Biochemistry ,Cohort Studies ,0302 clinical medicine ,Endocrinology ,Pregnancy ,Reference Values ,Prevalence ,Prospective Studies ,Subclinical infection ,030219 obstetrics & reproductive medicine ,biology ,Obstetrics ,Thyroid disease ,Female ,medicine.symptom ,Thyroid function ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug ,Adult ,endocrine system ,medicine.medical_specialty ,Adolescent ,Levothyroxine ,030209 endocrinology & metabolism ,Asymptomatic ,Young Adult ,03 medical and health sciences ,Hypothyroidism ,Thyroid peroxidase ,Internal medicine ,medicine ,Humans ,Autoantibodies ,business.industry ,Biochemistry (medical) ,Odds ratio ,medicine.disease ,United Kingdom ,Abortion, Spontaneous ,Infertility ,Asymptomatic Diseases ,biology.protein ,business ,Body mass index - Abstract
Objective To describe the prevalence of and factors associated with different thyroid dysfunction phenotypes in women who are asymptomatic preconception. Design Observational cohort study. Setting A total of 49 hospitals across the United Kingdom between 2011 and 2016. Participants Women aged 16 to 41years with history of miscarriage or subfertility trying for a pregnancy. Methods Prevalences and 95% confidence intervals (CIs) were estimated using the binomial exact method. Multivariate logistic regression analyses were conducted to identify risk factors for thyroid disease. Intervention None. Main Outcome Measure Rates of thyroid dysfunction. Results Thyroid function and thyroid peroxidase antibody (TPOAb) data were available for 19213 and 19237 women, respectively. The prevalence of abnormal thyroid function was 4.8% (95% CI, 4.5-5.1); euthyroidism was defined as levels of thyroid-stimulating hormone (TSH) of 0.44 to 4.50 mIU/L and free thyroxine (fT4) of 10 to 21 pmol/L. Overt hypothyroidism (TSH > 4.50 mIU/L, fT4 < 10 pmol/L) was present in 0.2% of women (95% CI, 0.1-0.3) and overt hyperthyroidism (TSH < 0.44 mIU/L, fT4 > 21 pmol/L) was present in 0.3% (95% CI, 0.2-0.3). The prevalence of subclinical hypothyroidism (SCH) using an upper TSH concentration of 4.50 mIU/L was 2.4% (95% CI, 2.1-2.6). Lowering the upper TSH to 2.50 mIU/L resulted in higher rates of SCH, 19.9% (95% CI, 19.3-20.5). Multiple regression analyses showed increased odds of SCH (TSH > 4.50 mIU/L) with body mass index (BMI) ≥ 35.0 kg/m2 (adjusted odds ratio [aOR] 1.71; 95% CI, 1.13-2.57; P = 0.01) and Asian ethnicity (aOR 1.76; 95% CI, 1.31-2.37; P < 0.001), and increased odds of SCH (TSH ≥ 2.50 mIU/L) with subfertility (aOR 1.16; 95% CI, 1.04-1.29; P = 0.008). TPOAb positivity was prevalent in 9.5% of women (95% CI, 9.1-9.9). Conclusions The prevalence of undiagnosed overt thyroid disease is low. SCH and TPOAb are common, particularly in women with higher BMI or of Asian ethnicity. A TSH cutoff of 2.50 mIU/L to define SCH results in a significant proportion of women potentially requiring levothyroxine treatment.
- Published
- 2020