Growth, puberty and testicular function in boys born small for gestational age with a nonspecific disorder of sex development

OBJECTIVE

Being born small for gestational age (SGA) is frequently associated with unexplained disorders of sex development (nonspecific DSD) in boys. Little is known about their future growth, puberty and testicular function. Our objective is to determine the long-term endocrine outcome of boys born SGA who have a nonspecific DSD.

DESIGN

Boys with a nonspecific DSD born SGA and appropriate for GA (AGA) were retrieved through the International Disorders of Sex Development registry and retrospective data collected, based on a spreadsheet containing 102 items.

PATIENTS AND MEASUREMENTS

In total, 179 boys were included, of which 115 were born SGA and 64 were born AGA. Their growth and pubertal development were compared. Serum LH, FSH, testosterone, AMH and inhibin B levels in infancy and puberty were analysed to assess testicular function.

RESULTS

At 2 years of age, 30% of SGA boys had incomplete or absent catch-up growth. Boys born SGA also had higher LH during minipuberty and lower testosterone in stimulation tests (p = 0.037 and 0.040, respectively), as compared to boys born AGA. No differences were observed in timing or course of puberty or end-pubertal hormone levels.

CONCLUSIONS

Almost one out of three SGA boys with a nonspecific DSD experiences insufficient catch-up growth. In addition, our data suggest dysfunction of infantile Leydig cells or altered regulation of the hypothalamic-pituitary-gonadal axis in SGA boys during childhood. Sex steroid production during puberty seems unaffected.

Thyroid ultrasound in IDDM

Insulin dependent diabetes mellitus (IDMM) is often associated with autoimmune thyroiditis (AIT) and a high prevalence of thyroid antibodies (TA). Ultrasound imaging of the thyroid may contribute to the evaluation of patients with AIT. We therefore investigated ultrasound findings of the thyroid in 83 IDDM patients (44F, 39M) with an age range of 2.3-22.3 yrs (median 11.1). Thyroid volume (ml) determined by ultrasound ranged between 1.3 and 17.9 (median 5.7). Thyroid volumes of 75 healthy children (32F, 43M) with an age range of 2.0 to 11.8 yrs (median 7.6) ranged between 1.6 and 13.2 ml (median 4.8) and did not show a significant difference from the IDDM group from age 4 to 12. TA were positive in 18.8% of the IDDM group. Thyroid volume was higher in TA (+) diabetics (p = 0.05), a finding which may be attributed to a higher percentage of cases with elevated TSH in the TA (+) group. Two diabetic patients showed non-homogeneous hypoechogenicity in the ultrasound compatible with AIT which was later confirmed in one of these cases by aspiration biopsy. Ultrasound imaging of the thyroid may contribute to the evaluation of patients with AIT in IDDM.