title: Maternal First Trimester TSH Concentrations: Do They Affect Perinatal and Endocrine Outcomes?
abstract: We aimed to examine the distribution of 1(st) trimester TSH and evaluate its association with perinatal outcomes and future development of maternal thyrotoxicosis. This retrospective cohort study included data of all women without prior thyroid disease who delivered a singleton at our medical center from 1/2001 to 12/2011 and had a 1(st) trimester TSH<4.0 mU/l. Women were divided according to 1(st) trimester TSH concentrations into quartiles and by predefined TSH values (mU/l): 1) TSH<0.1; 2) TSH 0.11-0.2; 3) TSH 0.21-0.4; and 4) TSH 0.4-4. Obstetrical outcomes, hCG concentrations, and future thyroid status were collected from electronic medical records. A total of 13 841 women fulfilled the inclusion criteria. Mean maternal TSH concentration at 5 weeks of gestation was 2.09±0.83 mU/l and decreased to 1.29±0.87 mU/l in weeks 8-9 with an increase towards the end of the 1(st) trimester. Odds ratio for future thyrotoxicosis was 3.64 in the lowest compared to the highest TSH quartile and 10.03 in those with TSH<0.1 compared to TSH 0.41-4 mU/l. Rates of female fetuses were higher in the low TSH quartiles and in the lower TSH groups, however baby gender was not associated with increased risk of future thyrotoxicosis. Low maternal 1(st) trimester TSH quartiles or concentrations were not associated with adverse pregnancy outcome. Only a minor fraction of pregnant women with a low first tirmester TSH subsequently developed future thyrotoxicosis.
authors.affiliation: Endocrine Unit, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Fraenkel
authors.affiliation: Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.|Clinical Research Center, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Shafat
authors.affiliation: Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.|Department of Obstetrics & Gynecology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Erez
authors.affiliation: Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.|Clinical Research Center, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Lichtenstein
authors.affiliation: Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.|Clinical Research Center, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: J
authors.initials: J
authors.lastname: Awesat
authors.affiliation: Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.|Clinical Research Center, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel.
authors.forename: V
authors.initials: V
authors.lastname: Novack
authors.affiliation: Endorine and Diabetes Clinic, Clalit Health Services, Jerusalem, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Tsur
mesh_terms: D006063:Chorionic Gonadotropin / Q000097:blood; D004703:Endocrine System / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First / Q000097:blood*; D012307:Risk Factors; D013971:Thyrotoxicosis / Q000097:blood; D013972:Thyrotropin / Q000097:blood*
chemical_list: D006063:Chorionic Gonadotropin; D013972:Thyrotropin