Virilisation of female preterm infants

Reference values for the external genitalia of full-term and pre-term female neonates

BACKGROUND AND OBJECTIVES

Identifying virilisation of the genitalia in female newborns early during the neonatal period is important to diagnose pathologies. However, there is no clear threshold for clitoromegaly or for the anogenital ratio. The objective of this study was to define reference values for the external genitalia of full-term and pre-term female neonates.

DESIGN

This was a prospective study of all females born in the study centre between May 2014 and July 2016. Clitoral length and anogenital ratio were measured in 619 newborns with a gestational age of 24+2 to 41+3 weeks during their first 3 days of life. Associations between the values at day 3 and gestational age, birth weight and other newborn characteristics were examined by linear regression.

RESULTS

The mean clitoral length at day 3 of life was 3.69±1.53 mm (n=551; 95th percentile, 6.5 mm; maximum, 8 mm), and the mean anogenital ratio was 0.42±0.09 (95th percentile, 0.58). There was no significant variation with gestational age or birth weight, and no significant difference between the results at day 0 and day 3.

CONCLUSION

These results suggest that clitoromegaly can be defined as a clitoral length >6.5 mm. Values ≥8 mm should prompt further investigations. An anogenital ratio >0.6 should be considered a sign of virilisation. Since clitoral size does not vary with gestational age or birth weight, clitoromegaly should not be attributed to prematurity.

The evolution of methods for urinary steroid metabolomics in clinical investigations particularly in childhood

The metabolites of cortisol, and the intermediates in the pathways from cholesterol to cortisol and the adrenal sex steroids can be analysed in a single separation of steroids by gas chromatography (GC) coupled to MS to give a urinary steroid profile (USP). Steroids individually and in profile are now commonly measured in plasma by liquid chromatography (LC) coupled with MS/MS. The steroid conjugates in urine can be determined after hydrolysis and derivative formation and for the first time without hydrolysis using GC-MS, GC-MS/MS and liquid chromatography with mass spectrometry (LC-MS/MS). The evolution of the technology, practicalities and clinical applications are examined in this review. The patterns and quantities of steroids changes through childhood. Information can be obtained on production rates, from which children with steroid excess and deficiency states can be recognised when presenting with obesity, adrenarche, adrenal suppression, hypertension, adrenal tumours, intersex condition and early puberty, as examples. Genetic defects in steroid production and action can be detected by abnormalities from the GC-MS of steroids in urine. New mechanisms of steroid synthesis and metabolism have been recognised through steroid profiling. GC with tandem mass spectrometry (GC-MS/MS) has been used for the tentative identification of unknown steroids in urine from newborn infants with congenital adrenal hyperplasia. Suggestions are made as to areas for future research and for future applications of steroid profiling. As routine hospital laboratories become more familiar with the problems of chromatographic and MS analysis they can consider steroid profiling in their test repertoire although with LC-MS/MS of urinary steroids this is unlikely to become a routine test because of the availability, cost and purity of the internal standards and the complexity of data interpretation. Steroid profiling with quantitative analysis by mass spectrometry (MS) after chromatography now provides the most versatile of tests of adrenal function in childhood.

Current state and recommendations for harmonization of serum/plasma 17-hydroxyprogesterone mass spectrometry methods

Background:

Mass spectrometry (MS)-based 17-hydroxyprogesterone (17OHP) methods show considerable variation in results in external quality assurance (EQA) programs. An understanding of the current status of MS-based serum/plasma 17OHP quantification is important to facilitate harmonization.

Methods:

A 50-item e-survey related to (1) laboratory characteristics, (2) pre-analytical considerations and (3) analysis of 17OHP was developed and circulated to clinical MS laboratories via professional associations in Asia Pacific, Europe and North America.

Results:

Forty-four laboratories from 17 countries completed the survey. Sample preparation varied between laboratories with protein precipitation and liquid-liquid extraction being the most common processes. Analyte separation was most commonly achieved by liquid chromatography (LC) using a C18 column and mobile phases of water, methanol and formic acid. The ions selected for quantification were 331>97 m/z or 331>109 m/z. Alternative transition ions were used as qualifiers. Twenty-seven of 44 respondents reported preparing their calibrators in-house and variations in material purity and matrix were evident. Nine of 44 laboratories did not participate in an EQA program, and half did not know if their method separated out isobars. The reference intervals, and also their partitioning, reported by the laboratories were highly discrepant, in some cases, by multiple folds.

Conclusions:

Although MS-based methods are similar in many facets, they are highly disparate. Five recommendations have been developed as an outcome of this survey to support the continued improvement of analysis of serum/plasma 17OHP by MS.

Case Report of Clitoral Hypertrophy in 2 Extremely Premature Girls With an Ovarian Cyst

Neonatal clitoromegaly is mainly attributed to in utero androgen exposure secondary to congenital adrenal hyperplasia. We report on 2 extremely premature girls with clitoromegaly, increased androgen levels, no salt wasting syndrome, and ovarian cyst. In case 1, the cyst liquid was aspired during ovarian hernia surgery and revealed high androgen levels. After aspiration, serum androgen levels decreased, as did clitoral size. In case 2, an ovarian cyst was seen on pelvic ultrasound. Aspiration was not indicated. The cyst regressed spontaneously on iterative pelvic ultrasounds, and her clitoromegaly decreased. Case 1 demonstrates the ovarian origin of this transient virilization. Cyst formation seems to be linked to the physiologic maturation of the hypothalamic-pituitary-ovarian axis. Thirteen cases of clitoromegaly with hyperandrogenism, without salt wasting syndrome, have been reported in extremely premature infants. In the context of clitoromegaly, we recommend ruling out in utero androgen exposure, adrenal hyperandrogenism, and disorders of sex development. We further recommend affirming hyperandrogenism by androgen assay and confirming ovarian origin with gonadotrophin assays and pelvic ultrasound. Drug therapy abstention and clinical and ultrasound monitoring are recommended because spontaneous regression of clitoral hypertrophy seems to be the most common outcome in the literature, as it was in our 2 observations.

A guide to understanding the steroid pathway: new insights and diagnostic implications

Steroid analysis has always been complicated requiring a clear understanding of both the clinical and analytical aspects in order to accurately interpret results. The literature relating to this specialised area spans many decades and the intricacies of the steroid pathway have evolved with time. A number of key changes, including discovery of the alternative androgen pathway, have occurred in the last decade, potentially changing our understanding and approach to investigating disorders of sexual development. Such investigation usually occurs in specialised paediatric centres and although preterm infants represent only a small percentage of the patient population, consideration of the persistence of the foetal adrenal zone is an additional important consideration when undertaking steroid hormone investigations. The recent expanded role of mass spectrometry and molecular diagnostic methods provides significant improvements for accurate steroid quantification and identification of enzyme deficiencies. However analysis of steroids and interpretation of results remain complicated. This review aims to provide an insight into the complexities of steroid measurement in children and offers an updated guide to interpretation, of serum and urine steroids through the presentation of a refined steroid pathway.

Postnatal virilization mimicking 21-hydroxylase deficiency in 3 very premature infants

Premature infants are known to have elevated 17-hydroxyprogesterone and adrenal androgen concentrations immediately after birth, but the levels decrease rapidly. Virilization of normal premature female infants as a result of these high androgens has not been described. Three premature female infants born at 24 to 25 weeks' gestation, with birth weights 550 to 880 g and significant neonatal complications were noted to develop clitoromegaly 2 weeks to 3 months after birth. All 3 had elevated 17-hydroxyprogesterone >100 nmol/L and testosterone >3 nmol/L concentrations. All were treated as simple virilizing 21-hydroxylase deficiency, but subsequent genetic analysis revealed no CYP21 mutations. Follow-up after discontinuation of treatment revealed no recurrent virilization and normal adrenal steroid levels. Postnatal virilization in sick premature girls may occur, and investigations may suggest 21-hydroxylase deficiency. Genetic analysis of CYP21 should be performed before the diagnosis is confirmed. Further studies are needed to better document the natural history and possible causes of postnatal adrenal androgen secretion in sick premature infants.