TY - JOUR
T1 - The prevalence of thyroid dysfunction and autoimmunity in women with history of miscarriage or subfertility
AU - Smith, Rima
AU - Tobias Garces, Aurelio
AU - Smith, Paul
AU - Middleton, Lee
AU - Sunner, Kirandeep
AU - Baker, Krystyna
AU - Farrell-Carver, Samantha
AU - Bender Atik, Ruth
AU - Agrawal, Rina
AU - Bhatia, Kalsang
AU - Chu, Justin
AU - Edi-Osagie, Edmond
AU - Ewies, Ayman
AU - Ghobara, Tarek
AU - Gupta, Pratima
AU - Jurkovic, Davor
AU - Khalaf, Yakoub
AU - Mulbagal, Khashia
AU - Nunes, Natalie
AU - Overton, Caroline
AU - Quenby, Siobhan
AU - Rai, Rajendra
AU - Raine-Fenning, Nick
AU - Robinson, Lynne
AU - Ross, Jackie
AU - Sizer, Andrew
AU - Small, Rachel
AU - Underwood, Martin
AU - Kilby, Mark
AU - Daniels, Jane
AU - Thangaratinam, Shakila
AU - Chan, Shiaoyng
AU - Boelaert, Kristien
AU - Coomarasamy, Arri
PY - 2020/8/1
Y1 - 2020/8/1
N2 - 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.
AB - 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.
KW - miscarriage
KW - preconception
KW - prevalence
KW - subfertility
KW - thyroid autoimmunity
KW - thyroid disease
UR - http://www.scopus.com/inward/record.url?scp=85087320491&partnerID=8YFLogxK
U2 - 10.1210/clinem/dgaa302
DO - 10.1210/clinem/dgaa302
M3 - Article
SN - 0021-972X
VL - 105
SP - 2667
EP - 2677
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 8
ER -