Delayed Puberty

Puberty does not begin on the same birthday for every adolescent, but there are limits to normal variation. Delayed puberty is evaluated when breast development has not begun by age 13 years in girls, or when testicular enlargement to at least 4 mL in volume or approximately 2.5 cm in length has not occurred by age 14 years in boys. Primary amenorrhea by approximately age 15 to 16 despite otherwise developing pubertal characteristics also requires evaluation. These thresholds are not diagnoses. They identify adolescents whose timing falls roughly two to two-and-a-half standard deviations later than the population mean and who need a structured assessment. The nurse should avoid reassuring a family that the adolescent is simply “a late bloomer” before growth, nutrition, chronic disease, gonadal function, and neurologic symptoms have been considered. The clinical question is not merely whether puberty is late. It is whether the reproductive axis is intact but delayed, suppressed by illness or inadequate energy availability, or unable to function because of hypothalamic-pituitary or gonadal disease.