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Gestational hypothyroidism: development of mild hypothyroidism in early pregnancy in previously euthyroid women

      Objective

      To determine the proportion of euthyroid women attending a fertility practice who develop hypothyroidism in very early pregnancy (gestational hypothyroidism [GHT]), and to examine the association of GHT with exogenous gonadotropin treatment.

      Design

      Retrospective cohort study.

      Setting

      A private reproductive medicine practice.

      Patient(s)

      All healthy women (N = 94) with infertility or recurrent pregnancy loss, TSH level <2.5 mIU/L, negative thyroid peroxidase antibodies at initial evaluation, and not taking thyroid medication, who conceived during an 18-month period.

      Intervention(s)

      Usual fertility care; 30 women who had received exogenous gonadotropins.

      Main Outcome Measure(s)

      Serum TSH level at the time of pregnancy detection.

      Result(s)

      Gestational hypothyroidism (TSH ≥ 2.5 mIU/L) developed in 23 of 94 women (24%). The mean increase in serum TSH level from initial evaluation to early pregnancy was 0.45 ± 0.08 [SE] mIU/L. There was a trend toward the association of GHT with use of exogenous gonadotropins. Gestational hypothyroidism was positively associated with initial prepregnancy TSH level.

      Conclusion(s)

      Euthyroid women may develop mild hypothyroidism in early pregnancy, especially after exogenous gonadotropin treatment. Appropriate vigilance will allow for timely levothyroxine treatment.

      Key Words

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      References

        • Klein R.Z.
        • Haddow J.E.
        • Fix J.D.
        • Brown R.S.
        • Hermosa R.J.
        • Pulkkinen A.
        • et al.
        Prevalence of thyroid deficiency in pregnant women.
        Clin Endocrinol (Oxf). 1991; 35: 41-46
        • Garber J.R.
        • Cobin R.H.
        • Gharib H.
        • Hennessey J.V.
        • Klein I.
        • Mechanick J.I.
        • et al.
        Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American association of Clinical Endocrinologists and the American Thyroid Association.
        Endocr Pract. 2012; 18: 988-1028
        • DeGroot L.
        • Abalovich M.
        • Alexander E.K.
        • Amino N.
        • Barbour L.
        • Cobin R.H.
        • et al.
        Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline.
        J Clin Endocrinol Metab. 2012; 97: 2543-2565
        • Blatt A.J.
        • Nakamoto J.M.
        • Kaufman H.W.
        National status of testing for hypothyroidism during pregnancy and postpartum.
        J Clin Endocrinol Metab. 2012; 97: 777-784
        • Casey B.M.
        • Dashe J.S.
        • Wells C.E.
        • McIntire D.D.
        • Byrd W.
        • Leveno K.J.
        • et al.
        Subclinical hypothyroidism and pregnancy outcomes.
        Obstet Gynecol. 2005; 105: 239-245
        • Baker V.L.
        • Rone H.M.
        • Pasta D.J.
        • Nelson H.P.
        • Gvakharia M.
        • Adamson G.D.
        Correlation of thyroid stimulating hormone (TSH) level with pregnancy outcome in women undergoing in vitro fertilization.
        Am J Obstet Gynecol. 2006; 194: 1668-1675
        • Stagnaro-Green A.
        Maternal thyroid disease and preterm delivery.
        J Clin Endocrinol Metab. 2009; 94: 21-25
        • Negro R.
        • Schwartz A.
        • Gismondi R.
        • Tinelli A.
        • Mangieri T.
        • Stagnaro-Green A.
        Increased pregnancy loss rate in thyroid antibody negative women with TSH levels between 2.5 and 5.0 in the first trimester of pregnancy.
        J Clin Endocrinol Metab. 2010; 95: E44-E48
        • Van den Boogaard E.
        • Vissenberg R.
        • Land L.A.
        • van Wely M.
        • van der Post J.A.
        • Goddijn M.
        • et al.
        Significance of (sub)clinical thyroid dysfunction and thyroid autoimmunity before conception and in early pregnancy: a systematic review.
        Hum Reprod Update. 2011; 17: 605-619
        • Glinoer D.
        The regulation of thyroid function in pregnancy: pathways of endocrine adaptation from physiology to pathology.
        Endocr Rev. 1997; 18: 404-433
        • Alexander E.K.
        • Marqusee E.
        • Lawrence J.
        • Jarolim P.
        • Fischer G.A.
        • Larsen P.R.
        Timing and magnitude of increases in levothyroxine requirements during pregnancy in women with hypothyroidism.
        N Engl J Med. 2004; 351: 241-249
        • Poppe K.
        • Glinoer D.
        • Tournaye H.
        • Schiettecatte J.
        • Devroey P.
        • van Steirteghem A.
        • et al.
        Impact of ovarian hyperstimulation on thyroid function in women with and without thyroid autoimmunity.
        J Clin Endocrinol Metab. 2004; 89: 3808-3812
        • Poppe K.
        • Velkeniers B.
        • Glinoer D.
        The role of thyroid autoimmunity in fertility and pregnancy.
        Nat Clin Pract Endocrinol Metab. 2008; 4: 394-405
        • Muller A.F.
        • Verhoeff A.
        • Mantel M.J.
        • DeJong F.H.
        • Berghout A.
        Decrease of free thyroxine levels after controlled ovarian hyperstimulation.
        J Clin Endocrinol Metab. 2000; 85: 545-548
        • Benaglia L.
        • Busnelli A.
        • Somigliana E.
        • Leonardi M.
        • Vannucchi G.
        • de Leo S.
        • et al.
        Incidence of elevation of serum thyroid-stimulating hormone during controlled ovarian hyperstimulation for in vitro fertilization.
        Eur J Obstet Gynecol Reprod Biol. 2014; 173: 53-57
        • Negro R.
        • Formoso G.
        • Mangieri T.
        • Pezzarossa A.
        • Dazzi D.
        • Hassan H.
        Levothyroxine treatment in euthyroid pregnant women with autoimmune thyroid disease: effects on obstetrical complications.
        J Clin Endocrinol Metab. 2006; 91: 2587-2591
        • Abalovich M.
        • Mittelberg L.
        • Allami C.
        • Gutierrez S.
        • Alcaraz G.
        • Otero P.
        • et al.
        Subclinical hypothyroidism and thyroid autoimmunity in women with infertility.
        Gynecol Endocrinol. 2007; 23: 279-283
        • Michalakis K.G.
        • Mesen T.B.
        • Brayboy L.M.
        • Yu B.
        • Richter K.S.
        • Levy M.
        • et al.
        Subclinical elevations of thyroid-stimulating hormone and assisted reproductive technology outcomes.
        Fertil Steril. 2011; 95: 2634-2637