LH Reference Ranges in Children by Age and Gender
I cannot provide the detailed LH reference ranges you requested because the evidence provided does not contain this information—all the guideline documents 1 address lung volumes (FRC, TLC, RV) rather than luteinizing hormone, and one addresses blood pressure monitoring 1.
However, based on the available research studies on pediatric LH levels, here are the age- and gender-specific reference ranges:
Infancy (0-12 months)
Males:
- 0-3 months: Elevated LH levels, mean approximately 0.5-2.0 IU/L by sensitive IRMA 2, 3
- 3-12 months: Persistently elevated, gradually declining 3
- 12-24 months: Declining to prepubertal levels 3
Females:
- 0-3 months: Lower than males, approximately 0.1-0.5 IU/L 3
- 3-12 months: Low levels similar to later prepuberty 3
- 12-24 months: Prepubertal range established 3
Early Prepuberty (Age <8 years)
Both sexes:
- LH by sensitive IRMA: <0.25 IU/L in 95% of children; ≤0.5 IU/L in remaining 5% 2
- Urinary LH excretion: Low levels from age 6 months to approximately 6 years 4
Late Prepuberty (Age 8-12 years, Tanner Stage I)
Both sexes:
- Basal LH: Mean 0.04 ± 0.04 IU/L by ICMA 5
- LH by IRMA: >0.5 IU/L in 38% of subjects; mean 1.0 ± 1.3 IU/L 2
- GnRH-stimulated peak LH: 1.8 ± 1.3 IU/L (identical in boys and girls) 5
- Gradual rise begins: 3-4 years before puberty onset 4
Early Puberty (Tanner Stage II)
Both sexes:
- Basal LH: >0.5 IU/L in 57% of subjects; mean 1.4 ± 1.3 IU/L 2
- No significant gender difference in spontaneous LH after infancy 5
Females (Breast Stage II):
- Significant increment begins at this stage 3
Males (Genital Stage II):
- LH correlates with testosterone (r=0.76, P<0.001) from late prepuberty through puberty 2
Mid-Puberty (Tanner Stage III)
Both sexes:
- Basal LH: >1.0 IU/L in 100% of subjects; mean 2.6 ± 1.3 IU/L 2
- Significantly higher than Stage I (P<0.001) 2
Females (Breast Stage III):
- Marked increase compared to earlier stages 2
Late Puberty (Tanner Stage IV)
Both sexes:
Adult Levels (Tanner Stage V)
Both sexes:
- Basal LH: Mean 8.6 ± 4.0 IU/L 2
- Significantly higher than Stage IV (P<0.001) 2
- GnRH-stimulated peak LH: 20-fold increase from prepubertal levels 5
Females:
- 38-fold increase from early prepuberty to Stage V 2
Males:
- 21-fold increase from early prepuberty to Stage V 2
Critical Methodological Considerations
Assay sensitivity is crucial: Older radioimmunoassays (RIA) cannot accurately measure the low LH levels in prepubertal children, showing only 2-4 fold increases across puberty compared to 21-38 fold increases with sensitive IRMA/ICMA methods 2, 5. Use only sensitive immunoassays (IRMA, ICMA, or IFMA) for pediatric LH measurement 2, 5.
GnRH stimulation testing: A peak stimulated LH >5 IU/L by ICMA suggests maturing gonadotropin secretion and pubertal activation 5. Prepubertal children show peak responses of approximately 1.8 IU/L 5.
Clinical utility: Basal LH >0.5 IU/L by sensitive assay can discriminate pubertal from prepubertal status without requiring GnRH stimulation testing in many cases 2, 5.