Abstract
Objective: Premature thelarche and precocious puberty are frequently diagnosed in girls even below 6 years of age and may be difficult to differentiate in the early stages. A GnRH test is often included in the diagnostic work-up, although interpretation of the GnRH test in girls below 6 years of age is challenging, as no reference interval exists for this age group. The objective is to determine the normal FSH and LH response to a GnRH test in healthy prepubertal girls below 6 years of age. Design and methods: A standardized GnRH test, baseline reproductive hormones, clinical evaluation and bone age were determined in all participants. Forty-eight healthy normal-weight girls aged 3.5 ± 0.2 years (range: 0.8-5.9 years) were included. Serum concentrations of LH and FSH were measured before and 30 min after the gonadorelin injection. Results: The 30-min LH responses (mean ± 2 s.d.) were 5.2 ± 4.0 and 2.9 ± 2.5 IU/L and the FSH responses were 23.3 ± 16.2 and 14.5 ± 10.3 IU/L in girls aged 0.8-3.0 years and 3.0-5.9 years respectively. This corresponds to upper cut-off limits for LH of 9.2 IU/L (<3 years) and 5.3 IU/L (3-6 years). The stimulated LH/FSH ratio was 0.23 ± 0.19 (range 0.06-0.43) and did not correlate with age. Conclusions: We found that LH increases up to 9.2 IU/L during GnRH test in healthy normal-weight girls below 3 years of age and that the stimulated LH/FSH ratio did not exceed 0.43. Our findings have important implications for appropriate diagnosis of central precocious puberty in girls below 6 years of age.
Original language | English |
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Journal | European Journal of Endocrinology |
Volume | 176 |
Issue number | 6 |
Pages (from-to) | 747-753 |
ISSN | 0804-4643 |
DOIs | |
Publication status | Published - Jun 2017 |
Keywords
- Algorithms
- Bone Development
- Child Development
- Child, Preschool
- Cohort Studies
- Denmark
- Diagnostic Techniques, Endocrine
- Female
- Follicle Stimulating Hormone, Human/blood
- Gonadotropin-Releasing Hormone/analogs & derivatives
- Hospitals, University
- Humans
- Infant
- Luteinizing Hormone/blood
- Normal Distribution
- Puberty, Precocious/blood
- Reference Values
- Sex Hormone-Binding Globulin