Comparison of universal screening with targeted high-risk case finding for diagnosis of thyroid disorders.
OBJECTIVE
Debate about the need for universal screening of thyroid dysfunction in pregnancy is ongoing. The present study aimed to compare universal screening with targeted high-risk case findings for early diagnosis of thyroid disorders in Iranian pregnant women.


METHODS
This cross-sectional prospective study was carried out on 1600 pregnant women in their first trimester. A checklist, including all related risk factors recommended by The American Thyroid Association, was completed for all participants. Serum concentrations of thyroxine (T4), T-uptake, TSH and thyroid peroxidase antibody (TPOAb) were measured and thyroid status was documented, based on hormonal measurements and clinical examinations.


RESULTS
There were 656 women (44.3%) that had at least one risk factor for thyroid diseases and were eligible for the targeted high-risk case finding (high-risk group) approach, while 55.7% had no risk factors (low-risk group). Using the universal screening approach, there were 974 women (65.8%) with normal thyroid status and 506 participants (34.2%) with thyroid disturbances, including overt hyperthyroidism (0.7%), overt hypothyroidism (1.1%), subclinical hypothyroidism (30.1%; positive TPOAb (5.5%) and negative TPOAb (24.6%); and euthyroid and positive TPOAb (2.3%). Of women with thyroid dysfunction, 64.4% were in the high-risk group and 35.6% were in the low-risk group (P<0.0001).


CONCLUSIONS
The targeted high-risk case finding approach overlooks about one-third of pregnant women with thyroid dysfunction. If ongoing prospective trials provide evidence on the efficacy of treating subclinical hypothyroidism in pregnancy, in populations with a low prevalence of presumed risk factors, the targeted high-risk case finding approach will be proven inefficient.
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Sima
S
Nazarpour
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran fah.tehrani@gmail.com.
Fahimeh Ramezani
FR
Tehrani
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Masoumeh
M
Simbar
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Maryam
M
Tohidi
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Hamid
H
AlaviMajd
Department of Reproductive Health and MidwiferyFaculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranReproductive Endocrinology Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranPrevention of Metabolic Disorders Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IranDepartment of BiostatisticsFaculty of Paramedicine, Shahid Beheshti University of Medical Sciences and Health Services, Tehran, IranEndocrine Research CenterResearch Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Fereidoun
F
Azizi
D000328:Adult; D001323:Autoantibodies / Q000097:blood; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis; D007037:Hypothyroidism / Q000175:diagnosis; D007492:Iran; D008403:Mass Screening; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*; D011261:Pregnancy Trimester, First; D018566:Pregnancy, High-Risk; D011446:Prospective Studies; D012307:Risk Factors; D013959:Thyroid Diseases / Q000175:diagnosis*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
D001323:Autoantibodies; C056626:thyroid microsomal antibodies; D013972:Thyrotropin; D013974:Thyroxine