title: Subclinical Hypothyroidism and Thyroid Autoimmunity Are Not Associated With Fecundity, Pregnancy Loss, or Live Birth.
abstract: BACKGROUND
  Prior studies examining associations between subclinical hypothyroidism and antithyroid antibodies with early pregnancy loss and live birth suggest mixed results and time to pregnancy (TTP) has not been studied in this patient population.
  
  
  OBJECTIVE
  This study sought to examine associations of prepregnancy TSH concentrations and thyroid autoimmunity with TTP, pregnancy loss, and live birth among women with proven fecundity and a history of pregnancy loss.
  
  
  METHODS
  This was a prospective cohort study from a large, randomized controlled trial that took place at four medical centers in the United States.
  
  
  METHODS
  Healthy women, ages 18-40 y, who were actively attempting to conceive and had one or two prior pregnancy losses and no history of infertility were eligible for the study.
  
  
  METHODS
  There were no interventions.
  
  
  METHODS
  TTP, pregnancy loss, and live birth.
  
  
  RESULTS
  Women with TSH ≥ 2.5 mIU/L did not have an increased risk of pregnancy loss (risk ratio, 1.07; 95% confidence interval [CI], 0.81-1.41) or a decrease in live birth rate (risk ratio, 0.97; 95% CI, 0.88-1.07) or TTP (fecundability odds ratio, 1.09; 95% CI, 0.90-1.31) compared with women with TSH <2.5 mIU/L after adjustment for age and body mass index. Similar findings were observed for women with thyroid autoimmunity and after additional adjustment for treatment assignment.
  
  
  CONCLUSIONS
  Among healthy fecund women with a history pregnancy loss, TSH levels ≥ 2.5 mIU/L or the presence of antithyroid antibodies were not associated with fecundity, pregnancy loss, or live birth. Thus, women with subclinical hypothyroidism or thyroid autoimmunity can be reassured that their chances of conceiving and achieving a live birth are likely unaffected by marginal thyroid dysfunction.
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Torie C
authors.initials: TC
authors.lastname: Plowden
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Enrique F
authors.initials: EF
authors.lastname: Schisterman
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Lindsey A
authors.initials: LA
authors.lastname: Sjaarda
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Shvetha M
authors.initials: SM
authors.lastname: Zarek
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Perkins
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Robert
authors.initials: R
authors.lastname: Silver
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Noya
authors.initials: N
authors.lastname: Galai
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Alan H
authors.initials: AH
authors.lastname: DeCherney
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research (T.C.P., E.F.S., L.A.S., S.M.Z., N.J.P., S.L.M.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, Maryland, 20852; Program in Reproductive and Adult Endocrinology (T.C.P., S.M.Z., A.H.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, 20892; Department of Obstetrics and Gynecology (R.S.), University of Utah Health Sciences Center, Salt Lake City, Utah 84132; and Department of Statistics (N.G.), University of Haifa, Mount Carmel, Haifa, Israel 31905.
authors.forename: Sunni L
authors.initials: SL
authors.lastname: Mumford
mesh_terms: D000022:Abortion, Spontaneous / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D001323:Autoantibodies; D015551:Autoimmunity / Q000276:immunology*; D005260:Female; D005298:Fertility / Q000276:immunology*; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology*; D050498:Live Birth; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D013961:Thyroid Gland / Q000276:immunology*; D055815:Young Adult
chemical_list: D001323:Autoantibodies