Normal sex differences in prenatal growth and abnormal prenatal growth retardation associated with 46,XY disorders of sex development are absent in newborns with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Sex dimorphism of weight and length at birth: evidence based on disorders of sex development

BACKGROUND

Males have higher weight and length at birth than females.

AIM

To verify the influence of the Y chromosome and the action of intrauterine androgens on weight and length at birth of children with Disorders of Sex Development (DSD).

SUBJECTS AND METHODS

A cross-sectional and retrospective study. Patients with Turner syndrome (TS), complete (XX and XY), mixed (45,X/46,XY) and partial (XY) gonadal dysgenesis (GD), complete (CAIS) and partial (PAIS) androgen insensitivity syndromes and XX and XY congenital adrenal hyperplasia (CAH) were included. Weight and length at birth were evaluated.

RESULTS

Weight and length at birth were lower in TS and mixed GD when compared to XY and XX DSD cases. In turn, patients with increased androgen action (117 cases) had higher weight and length at birth when compared to those with absent (108 cases) and decreased (68 cases) production/action. In birthweight, there was a negative influence of the 45,X/46,XY karyotype and a positive influence of increased androgen and gestational age. In birth length, there was a negative influence of the 45,X and 45,X/46,XY karyotypes and also a positive influence of increased androgen and gestational age.

CONCLUSIONS

The sex dimorphism of weight and length at birth could possibly be influenced by intrauterine androgenic action.

Birth Size in Neonates with Congenital Adrenal Hyperplasia due to 21-hydroxylase Deficiency

OBJECTIVE

Classic congenital adrenal hyperplasia (CAH) secondary to 21-hydroxylase deficiency is characterized by increased prenatal adrenal androgen secretion. There are a small number of reports in the literature showing higher birth weight and length in CAH newborns.

METHODS

We analyzed birth weight and length data of 116 German newborns (48 boys, 68 girls) with classic CAH who were born during the period from 1990 to 2017. All children have been followed or are currently treated as outpatients in our clinic. All children were born at term. The mothers were healthy and their pregnancies were uneventful. The diagnosis of CAH was confirmed by molecular analyses of the CYP21A2 gene. Birth data were calculated as standard deviation (SD) scores according to German reference values.

RESULTS

Weight and length in male CAH newborns (mean ± SD) (3601±576 g; 52.4±2.85 cm) were significantly higher than in female CAH newborns (3347±442 g; 51.2±2.55 cm), but male-female differences in the CAH cohort were lost when the data were converted into SD scores. The birth sizes of the CAH newborns did not differ from the reference group. The birth sizes also did not differ between the different CAH genotypes. Maternal age, mode of delivery and maternal parity had no influence on birth size.

CONCLUSION

Our data show that prenatal hyperandrogenism does not affect fetal growth.

Transient Postnatal Gonadal Activation and Growth Velocity in Infancy

BACKGROUND AND OBJECTIVE

Transient activation of the hypothalamic-pituitary-gonadal axis with a sex steroid surge is observed in boys and girls during the first months of life. However, the role of sex steroids in the regulation of growth has not been substantiated in infancy. We tested the hypothesis that testosterone (T) surge, known to be higher in infant boys than in girls during the transient postnatal gonadal activation regulates linear growth in infants.

METHODS

To characterize in detail the linear growth velocity (GV) differences between genders in the normal population in early infancy, we evaluated growth of 18 570 healthy infants (51.0% boys) with 162 003 height measurements from birth to 12 months of age. GV was monitored and compared with serially measured urinary T and estradiol levels and serum insulin-like growth factor 1 levels in 84 healthy infants (45% boys) during the first 6 months of life.

RESULTS

GV was significantly faster from birth to 6 months of age in boys than in girls (P ≤ .01). The greatest GV difference, 4.1 cm per year, was observed at 1 month of age, simultaneously with the peak of postnatal gonadal activation. In the mixed model analysis, GV showed a significant positive association with T in both genders (parameter estimate up to 0.62, 95% confidence interval 0.44-0.81).

CONCLUSIONS

These results provide a new insight into the regulation of growth in infants and elucidate a novel biological role of the transient postnatal gonadal activation in growth regulation.

Update on disorders of sex development

PURPOSE OF REVIEW

To review the recent information regarding disorders of sex development (DSD) which contribute to, as well as highlight, the need for greater understanding of genetic mutations and the dire need for specific outcome information.

RECENT FINDINGS

New information is primarily related to the identification of genetic mutations and other gene variations that impact reproductive system development. These new data add to the increasingly complex list of genes and the multigenetic effects involved in DSD. Several reviews outline the approach to diagnosis and management of the patient with DSD and the importance of a multidisciplinary team. These reviews continue to demonstrate the lack of specific guidelines for complex DSD patients for whom sex assignment is problematic.

SUMMARY

Although genetic research continues to define new and multigenetic factors involved in the development of DSD, this review of the medical literature also underscores the fact that scientific understanding remains inadequate in many areas of DSD to provide solid guidelines for approaching the more controversial questions in the DSD patient. Accordingly, the need for larger, outcome studies using subjects with verified diagnoses are needed. Optimally, these studies would account for potentially confounding differences in genetic, social, and psychological factors to help answer the pressing question facing every clinician dealing with DSD patients - what is the relationship between medical decision-making (such as sex assignment and genital surgery) and future quality of life and adaptation.