title: Incidence of elevation of serum thyroid-stimulating hormone during controlled ovarian hyperstimulation for in vitro fertilization.
abstract: OBJECTIVE
  To evaluate the rate of euthyroid women encountering an elevation of serum TSH above the threshold of 2.5 mIU/L during controlled ovarian hyperstimulation (COH) for IVF.
  
  
  METHODS
  Six-month prospective cohort study on 175 consecutive euthyroid women undergoing their first IVF cycle. Serum TSH assessments were performed before COH, at the time of hCG administration and at +16 days after hCG administration. Women were eligible if serum TSH tested the month preceding the IVF cycle was 0.4-2.5 mIU/L. A history of thyroid disorders was an exclusion criterion.
  
  
  RESULTS
  Serum concentrations of TSH at the three scheduled assessments were 1.5±0.5, 2.2±1.0 and 2.1±1.1 mIU/L, respectively. A statistically significant increase occurred between basal levels and levels at the time of hCG administration (p<0.001). Afterwards, levels remained stable (p=0.49). Serum TSH at the time of hCG administration exceeded the threshold of 2.5 mIU/L in 61 subjects, corresponding to 35% (95% CI: 28-42%). At +16 days after hCG administration, this event was observed in 47 subjects (27%, 95% CI: 21-34%). Baseline characteristics of women who did and did not exceed the threshold were similar apart from basal serum TSH, which was higher in the former group. The OR was 7.6 (95%CI: 2.9-20.2) per mIU/L (p<0.001). Cycle outcome and pregnancy rate were also similar.
  
  
  CONCLUSIONS
  Serum TSH exceeds the threshold of 2.5 mIU/L during COH in one out of three women who are euthyroid prior to enter an IVF cycle. Further evidence is warranted to elucidate the clinical relevance of our findings.
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
authors: Laura
authors: L
authors: Benaglia
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy; Department of Obstetrics and Gynecology, Università degli Studi di Milano, Milan, Italy. Electronic address: andreabusnelli@live.it.
authors: Andrea
authors: A
authors: Busnelli
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
authors: Edgardo
authors: E
authors: Somigliana
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy; Department of Obstetrics and Gynecology, Università degli Studi di Milano, Milan, Italy.
authors: Marta
authors: M
authors: Leonardi
authors: Endocrine and Diabetology Unit, Fondazione IRCCS Cà Granda, Milan, Italy.
authors: Guia
authors: G
authors: Vannucchi
authors: Endocrine and Diabetology Unit, Fondazione IRCCS Cà Granda, Milan, Italy.
authors: Simone
authors: S
authors: De Leo
authors: Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy.
authors: Laura
authors: L
authors: Fugazzola
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy.
authors: Guido
authors: G
authors: Ragni
authors: Department of Obstetrics and Gynecology, Fondazione Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy; Department of Obstetrics and Gynecology, Università degli Studi di Milano, Milan, Italy.
authors: Luigi
authors: L
authors: Fedele
mesh_terms: D000328:Adult; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D010062:Ovulation Induction; D011237:Predictive Value of Tests; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood*
chemical_list: D013972:Thyrotropin
keywords: Controlled ovarian hyperstimulation; IVF; TSH