IMPE Abstracts

Introduction: Minipuberty describes the transient sex-specific activation of the hypothalamic-pituitary-gonadal (HPG) axis during the first 2 years in girls. Data in preterm are scarce, but It seems that the HPG axis activation is more intense and prolonged compared with full-term infants, resulting in higher sex steroid concentrations, sometimes with extreme pubertal characteristics.

Clinical case: A female infant presented genitorrhagia at 4 months of chronological age, initially suspecting a traumatic injury secondary to urethral catheterization. She had a history of being born at 26 weeks due to maternal hypertensive syndrome, performing an emergency cesarean section. She was born with adequate weight and length for her gestational age (W 775g (p20), L 33cm (p33), HC 24cm (p31)). She entered to neonatal ICU and evolved with multiple complications, associated with her prematurity. Fast echography at 3 months requested for abdominal distention showed a left ovary approximately 3cc and right ovary <2cc. Pelvic ultrasound at 4 months showed a uterus of 2.8cm of length, with a thick endometrial line of approximately 6mm, with clear predominance of the body over the neck. The right ovary shows a cystic appearance with multiple "daughter" cysts in the periphery, of 8.9cc. The left ovary shows a microfollicular pattern and measures 1.9cc. A clinical presentation compatible with minipuberty was proposed, with a right ovary that despite its size does not present a risk of torsion, deciding on expectant management and re-evaluation. No tumor markers were evaluated as the ovarian cysts “changed” ovary. After a month, an increase in breast volume was observed (bilateral Tanner stage 2), and again she presented genital bleeding: dark red, scarce, for a week. Vaginal bleeding was suspected on this occasion, with FSH 2.3mIU/mL, LH 2.35mIU/mL, Estradiol 49.9pg/mL. New pelvic ultrasound revealed a uterus of 4.0cm, predominance of the body over the neck, 2mm thick endometrial echogenic line. Right ovary showed large follicles and presents an approximate volume of 5cc and left ovary with normal morphology measuring 0.9cc. She presented 3 cycles every 4 weeks, without new episodes of bleeding from 6 months of chronological age. No development of pubic hair, and an adequate weight increase was observed. Thyroid function was always normal, and no signs of intracranial hypertension were observed.

Conclusion: The follow-up of this extreme preterm female infant with a central puberty suggests an exaggerated minipuberty. Differential diagnosis of vaginal bleeding must consider this phenomenon in this age group (CONICYT Grant 21160500).