Subclinical Hypothyroidism and Normogonadotropic Anovulation
Condition: Polycystic Ovary Syndrome; Hypothalamic-Pituitary-Ovarian Axis Dysfunction (Disorder)
MeSH terms: Polycystic Ovary Syndrome; Pituitary Diseases; Anovulation; Hypothyroidism
Study type: Observational

Summary: 
      Thyroid hormones (TH) can modify the functioning of the hypothalamic-pituitary-ovarian axis,
      affecting the functions of granulosa cells and the development and apoptosis of preantral
      follicles. TH receptors are present within the oocytes, and TH and anti-thyroid antibodies
      (ATA) are present in the follicular fluid. Improper thyroid function can cause ovulation
      disorders, luteal phase failure, impaired endometrial receptivity and result in implantation
      failures and recurrent miscarriages. While overt hypothyroidism is treated to improve
      fertility, the effect of subclinical hypothyroidism (SCH) and the presence of circulating
      ATAs on fertility and obstetric outcomes is uncertain and data on ovarian reserve rates are
      conflicting. Among the causes of ovulation disorders (group II according to the WHO
      classification), polycystic ovary syndrome (PCOS) dominates, found in 3-15% of women of
      reproductive age, and the remaining group of causes is the so-called
      Hypothalamic-Pituitary-Ovarian Axis Dysfunction (HPOD). The exact etiology of both entities
      is unknown.
    

Detailed description: 
      Purpose of the study

      Evaluation of ovarian reserve indices in women with normogonadotropic anovulation with SCH
      and without thyroid disease.

      Detailed objectives

      i) Assessment of AMH, FSH, LH, estradiol, astral follicle count (AFC)/ovarian volume in the
      subpopulation of women with PCOS and SCH compared to women with PCOS without thyroid disease
      ii) Assessment of AMH, FSH, LH, estradiol, AFC/ovarian volume in the subpopulation of women
      with HPOD (other than PCOS) with SCH compared to women with HPOD without thyroid disease iii)
      Comparison of AMH, FSH, LH, estradiol, AFC/ovarian volume in women with PCOS and HPOD with
      and without thyroid disease and evaluation of correlation with US ovarian morphology iv)
      Calculation of the cut-off point of AMH concentration correlating with a high probability of
      PCOS diagnosis and TSH correlating with unfavorable parameters of ovarian function/HPO axis.
    

Intervention name(s): Comparison of laboratory test results in women in the 4 study arms
Intervention type(s): Other
Intervention description(s): Comparison of AMH, FSH, LH, estradiol, AFC/ ovarian volume on ultrasound in women in the 4 study arms
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The study group will consist of women aged 18-45, diagnosed due to menstrual disorders
        and/or infertility due to ovulation disorders. Inclusion criteria will include age 18-45
        and euthyroidism. The exclusion criteria will be: i) diagnosed and treated thyroid
        dysfunction, ii) history of thyroidectomy. The study population of women will be
        characterized in terms of demographic (age, BMI) and obstetric data (pregnancy, childbirth,
        miscarriage, cycle length, infertility).
      
Keywords: Polycystic ovary syndrome; Hypothalamic-Pituitary-Ovarian axis dysfunction; Ovarian reserve; Anovulation; Any-Mullerian hormone