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Dynamic changes in LH/FSH ratios in infants with normal sex development

Marie Lindhardt Ljubicic1,2, Alexander S Busch1,2, Emmie N Upners1,2

  • 1Department of Growth and Reproduction, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.

European Journal of Endocrinology
|May 6, 2022
PubMed

Insights

The luteinizing hormone (LH) to follicle-stimulating hormone (FSH) ratio in infant serum and urine effectively distinguishes between males and females. This LH/FSH ratio serves as a reliable sex marker throughout the first year of life.

Area of Science:

  • Pediatric Endocrinology
  • Reproductive Endocrinology
  • Biomarker Discovery

Background:

  • The ratio of luteinizing hormone (LH) to follicle-stimulating hormone (FSH) is not well-established in infancy.
  • Understanding hormonal profiles in infants is crucial for assessing reproductive health and development.

Purpose of the Study:

  • To evaluate serum and urinary LH/FSH ratios as potential markers for sex determination in healthy infants.
  • To establish age-specific cutoffs for LH/FSH ratios in differentiating sexes during early childhood.

Main Methods:

  • A prospective, longitudinal cohort study involving 236 healthy infants (0-1.2 years).
  • Collection and analysis of 567 serum and 603 urine samples.
  • Assessment of diagnostic accuracy, including sensitivity and specificity, for LH/FSH ratios in sex determination.

Main Results:

  • LH/FSH ratios in both serum and urine were significantly higher in males with minimal overlap between sexes.
  • LH/FSH ratios demonstrated excellent accuracy in distinguishing sex from birth to 1.2 years.
  • Median sensitivities and specificities ranged from 93% to 100% with narrow confidence intervals.

Conclusions:

  • Serum and urinary LH/FSH ratios are highly effective discriminators of sex in healthy infants throughout the first year of life.
  • The findings suggest the LH/FSH ratio can be a valuable tool in pediatric diagnostics.
  • Further research is needed to clarify the clinical applications of these hormonal ratios.
Abstract

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