title: THE LONG-TERM IMPACT OF CONTROLLED OVARIAN HYPERSTIMULATION ON THYROID FUNCTION.
abstract: OBJECTIVE
  Evidence on the long-term impact of controlled ovarian hyperstimulation (COH) on thyroid function is scarce. To investigate this, we report on serum thyroid-stimulating hormone (TSH) modifications in euthyroid and hypothyroid women during COH and 3 months after the end of the stimulation cycle.
  
  
  METHODS
  Women who underwent in vitro fertilization (IVF) and who did not become pregnant were eligible. Cases were women with treated hypothyroidism and basal serum TSH <2.5 mIU/L. Controls were euthyroid women matched to cases by age and basal serum TSH. Women could be included if serum TSH was available at 4 time points: prior to initiating COH (time 1); at the time of human chorionic gonadotropin (hCG) administration (time 2); 16 days after hCG administration (time 3); and 3 months after the end of the IVF cycle (time 4).
  
  
  RESULTS
  Thirty-seven case-control pairs were included. Serum TSH at times 1, 2, 3, and 4 was 1.7 ± 0.6, 3.1 ± 1.4, 3.1 ± 1.3, and 2.7 ± 1.7 mIU/L, and 1.7 ± 0.6, 2.9 ± 1.0, 2.7 ± 1.0, and 1.9 ± 0.7 mIU/L among cases and controls, respectively. A statistically significant difference emerged at time 4 (P<.001). In both groups, serum TSH was higher at time 4 compared to time 1. Serum TSH exceeded the recommended threshold of 2.5 mIU/L at time 4 in 51% of cases (95% confidence interval [CI], 35 to 68%) and in 16% of controls (95% CI, 4 to 28%) (P = .003).
  
  
  CONCLUSIONS
  COH seems to have a long-term impact on TSH levels. The magnitude of this effect is particularly pronounced in hypothyroid women.
authors.forename: Andrea
authors.initials: A
authors.lastname: Busnelli
authors.forename: Edgardo
authors.initials: E
authors.lastname: Somigliana
authors.forename: Stefania
authors.initials: S
authors.lastname: Ferrari
authors.forename: Francesca
authors.initials: F
authors.lastname: Filippi
authors.forename: Guia
authors.initials: G
authors.lastname: Vannucchi
authors.forename: Laura
authors.initials: L
authors.lastname: Fugazzola
authors.forename: Luigi
authors.initials: L
authors.lastname: Fedele
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D006063:Chorionic Gonadotropin / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000150:complications / Q000503:physiopathology; D007247:Infertility, Female / Q000188:drug therapy / Q000503:physiopathology; D010062:Ovulation Induction / Q000009:adverse effects / Q000706:statistics & numerical data; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000503:physiopathology; D012189:Retrospective Studies; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000187:drug effects* / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D013972:Thyrotropin