Discordant fetal sex on NIPT and ultrasound

Ultrasound and magnetic resonance imaging features of fetal urogenital anomalies: A pictorial essay

This pictorial essay focuses on ultrasound (US) and magnetic resonance imaging (MRI) features of fetal urogenital anomalies. Fetal urogenital malformations account for 30%-50% of all anomalies discovered during pregnancy or at birth. They are usually detected by fetal ultrasound exams. However, when ultrasound data on their characteristics is insufficient, MRI is the best option for detecting other associated anomalies. The prognosis highly depends on their type and whether they are associated with other fetal abnormalities.

Unbalanced X;Y translocations carrying SRY in prenatal settings: Clinical, molecular, and cytogenetic analysis of three cases

BACKGROUND

Generally, the translocation of SRY onto one of the X chromosomes leads to 46, XX testicular disorders of sex development, a relatively rare condition characterized by the presence of testicular tissue with a 46, XX karyotype. Three prenatal cases of unbalanced X; Y translocation carrying SRY were identified in this study.

METHODS

Structural variants were confirmed using single nucleotide polymorphism array and chromosomal karyotyping. X chromosome inactivation (XCI) was also analyzed. Detailed clinical features of the three cases were collected.

RESULTS

We identified two fetuses with maternal inherited unbalanced X; Y translocations carrying SRY and skewed XCI presenting with normal female external genitalia, and one fetus with de novo 46, XX (SRY+) and random XCI manifested male phenotypic external genitalia.

CONCLUSION

This study reports that cases with unbalanced X; Y translocations carrying SRY manifested a normal female external genitalia in a prenatal setting. We speculate that the skewed XCI mediates the silence of SRY. In addition, our study emphasizes that combining clinical findings with pedigree analysis is critical for estimating the prognosis of fetuses with sex chromosome abnormalities.

Prenatal Findings in Postnatal Cases of Disorders of Sex Development: Experience from a Tertiary-Specialized Center in Brazil

INTRODUCTION AND OBJECTIVE

Prenatal suspicion of disorders/differences of sex development (DSDs) is a relatively new phenomenon. The aim of this study was to review the prenatal findings of DSD cases postnatally diagnosed in our tertiary referral center.

METHODS

We evaluated 57 DSD cases with sex ambiguity who had undergone prenatal ultrasound with phenotypic sex assessment and/or cell-free fetal DNA (cffDNA) for genotypic sex assessment.

RESULTS

Prenatal cffDNA had been performed in 32 cases, being positive (suggestive of male genotypic sex) in 26 and negative (suggestive of female genotypic sex) in 6. Five with cffDNA negative had a prenatal ultrasound indicating female external genitalia, in turn, in those with cffDNA positive, only two had a prenatal ultrasound indicating male external genitalia. Our postnatal data showed that when external genitalia were female or poorly virilized, prenatal ultrasound indicated female sex, but in cases of higher degree of virilization, ultrasound showed similar rates of male, female, or undetermined sex. Regarding the karyotype, our data showed those with XY karyotype had positive cffDNA, those with XX karyotype had negative cffDNA, and all five with sex chromosome anomalies had positive cffDNA because they were 45,X/46,XY. We suggested an algorithm to investigate these cases during gestation, including evaluation of uterus, fetal growth, and malformations.

CONCLUSION

We suggest that the parents should be counseled prenatally by a dedicated multidisciplinary team with experience in DSD management and evaluated as soon as possible after birth.

Ethical concerns surrounding sex prediction using noninvasive prenatal screening from pediatric endocrinologists' perspective

Noninvasive prenatal screening (NIPS) with predicted fetal sex chromosomes included in the results has become increasingly available for pregnant individuals. Predicted fetal sex chromosome results from NIPS are interpreted so as to equate sex chromosomes with sex and gender. As pediatric endocrinologists, we worry about how this use of NIPS harmfully reinforces sex and gender binaries and sets potentially inaccurate assumptions about what the identified chromosomes mean. We use a hypothetical case based on our clinical experience in which the NIPS report of fetal sex does not conform to expectations at birth to highlight ethical concerns surrounding this practice. The use of NIPS for fetal sex chromosome prediction has the potential to perpetuate stigma and bring psychological harm to parents and their future children, particularly those who are intersex, transgender, and gender diverse. The medical community should adopt an approach to the use of NIPS for fetal sex chromosome prediction that recognizes the spectrums of sex and gender to avoid reproducing stigma towards sex- and gender-diverse individuals and associated harms.

Imaging in fetal genital anomalies

Genital anomalies are a heterogeneous group of congenital pathologies that have become increasingly relevant since the Chicago Consensus of 2005. Their postnatal diagnosis has developed significantly in the last two decades, while prenatal diagnosis seems to be underdeveloped, with few protocols available, fragmented scientific literature, and low diagnostic rates. This review aims to examine the current status of this subspecialty from the perspective of prenatal imaging. Indications for the evaluation of fetal genitalia can be divided into medical and non-medical reasons. Medical reasons include sex-linked disorders, detection of other anomalies, relevant family history, or multiple pregnancy. Non-medical reasons include parental request for sex disclosure. Disclosure of fetal sex may be associated with ethical, legal, and medical issues. The main imaging technology used is 2D ultrasound, although there are other complementary techniques such as 3D, MRI, or Color Doppler. Regarding working methodology, several authors have drawn attention to the lack of standardized protocols and guidelines. Most guidelines tend to limit their recommendations to study indications and ethical issues. Technical proposals, measurements, or working methods have not yet been standardized. Fetal sex determination is usually divided into early and late gestation. Early gestation is based on the sagittal sign. Late gestation is based on direct visualization. There are several measurements to describe male and female genitalia, such as penile length, bilabial diameter, or scrotal diameter. Prenatal diagnosis of genital pathologies presents some particularities such as the wide spectrum of phenotypes, the high frequency of associated deformities, or the time of diagnosis. Some of the most frequent pathologies are ambiguous genitalia, fetal sex discordance, hypospadias, micropenis, clitoromegaly, ovarian cysts, hydro(metro)colpos, and cloacal anomalies. Higher-quality studies and direction from scientific societies through the implementation of clinical guidelines are needed.

Differences of sexual development: genetic counseling considerations in the prenatal setting

PURPOSE OF REVIEW

With the rapid adoption of noninvasive prenatal screening (NIPS), predictive fetal sex information is available early in pregnancy. This information can conflict with the results of other prenatal tests such as fetal ultrasound or diagnostic testing and raise the possibility of a fetal difference of sexual development (DSD). In this review, we describe recent studies examining the counseling and outcomes of prenatally suspected DSD.

RECENT FINDINGS

Discordance in prenatal genetic testing results can cause confusion and anxiety in families as expectations of testing are not often discussed in detail prior to testing. There are no established guidelines for the counseling or management of such situations.

SUMMARY

We present case vignettes to highlight relevant counseling points and considerations to aid in the development of guidelines and best practices in the management of DSD in the prenatal setting.

Babies born with ambiguous genitalia: Developing an educational resource for Australian midwives

PROBLEM AND BACKGROUND

The birth of a baby with ambiguous genitalia is rare and usually unexpected. Parents often receive inconsistent language from health-professionals after the birth. Initial interaction with the birth team has long-term consequences for families with babies born with ambiguous genitalia.

AIM

Understand the current practices on the day of birth and explore knowledge gaps for midwives regarding babies born with ambiguous genitalia. Develop educational content that can enable midwives to respond appropriately when the sex of a baby is unclear.

METHODS

This study included two phases, utilising qualitative descriptive research design with semi-structured interviews to understand the experiences of midwives caring for babies with ambiguous genitalia and their families. The findings informed the development a midwifery educational resource using these qualitative findings.

FINDINGS

Our analysis of 14 interviews with Australian midwives identified that they had no formal education to support families with a baby with ambiguous genitalia. Emotional support, advocacy and medical information translation were areas midwives perceived as essential skills to support these families.

DISCUSSION

Midwives provide a unique role in parental birth experiences. Themes that arose emphasised their psychosocial support role but lacked formal education and guidance on this topic. Midwives had learnt from the media about babies born with ambiguous genitalia and wanted evidence-based education to support parents. Midwife education focusing on both psychosocial and clinical care for parents and their baby with ambiguous genitalia is crucial.

CONCLUSION

Midwives can play a pivotal role in supporting parents with a baby with ambiguous genitalia. Themes from this qualitative study informed the development of a midwifery education digital resource.

Fetal Genotype-Phenotype Sex Discordance: A Case of 5-Alpha-Reductase Deficiency

OBJECTIVE

To describe the prenatal and postnatal diagnostic workup leading to the diagnosis of 5-alpha-reductase type 2 deficiency (5AR2D) in a case of 46,XY disorder of sex development (DSD).

CASE REPORT

A first-trimester noninvasive prenatal test (NIPT) on maternal blood revealed a male fetus with a low risk of aneuploidy. However, a female fetus was identified at the second-trimester scan. A repeat sample revealed similar results and ruled out the possibility of both a sample swap or a vanishing twin. At birth, phenotypically female external genitalia were evident, with testes noted in the labioscrotal area. Neonatal blood confirmed a 46,XY complement and a 46,XY DSD genetic panel revealed a 5AR2D.

CONCLUSION

Our case and others described in the literature demonstrate that fetal sex discordance detected by a combination of NIPT and subsequent ultrasound examination can be associated with several biological conditions, with DSD being the most significant.

Establishing a molecular genetic diagnosis in children with Differences of Sex Development - a clinical approach

Background Despite distinct underlying aetiologies, the clinical phenotypes and hormonal profiles of children with various differences of sex development (DSD) are often similar, which presents challenges to ascertaining an accurate diagnosis on clinical grounds alone. Associated features and important clinical outcomes can, however, vary significantly in different DSD, thus establishing an accurate molecular diagnosis may have important implications for decision-making and management planning in a given individual. Summary The wider availability of next generation sequencing techniques in recent years has led to recommendations for earlier integration of genetic testing in the diagnostic pathway of children with DSD. This review provides a practical overview of the clinical applications, advantages and limitations of the more commonly available diagnostic genetic tests and outlines a suggested approach to testing. The potential clinical implications of a confirmed genetic diagnosis on subsequent management pathways for individuals with DSD, as well as challenges that remain to be addressed are also outlined. Key messages Despite significant improvements in our understanding of the complex genetic pathways that underlie DSD, an accurate diagnosis still eludes many affected individuals. Establishing a molecular diagnosis provides aetiological certainty, enabling improved information for families and individualised clinical management, including monitoring or prophylactic intervention where higher longer-term health risks exist. A stepwise approach to genomic testing is recommended to afford highest diagnostic yield from available resources. Looking forward, collaborative multicentre prospective studies will be required to assess the true impact of a genetic diagnosis on improving clinical care pathways and health, wellbeing and patient-reported outcomes for individuals with DSD.

Towards improved genetic diagnosis of human differences of sex development

Despite being collectively among the most frequent congenital developmental conditions worldwide, differences of sex development (DSD) lack recognition and research funding. As a result, what constitutes optimal management remains uncertain. Identification of the individual conditions under the DSD umbrella is challenging and molecular genetic diagnosis is frequently not achieved, which has psychosocial and health-related repercussions for patients and their families. New genomic approaches have the potential to resolve this impasse through better detection of protein-coding variants and ascertainment of under-recognized aetiology, such as mosaic, structural, non-coding or epigenetic variants. Ultimately, it is hoped that better outcomes data, improved understanding of the molecular causes and greater public awareness will bring an end to the stigma often associated with DSD.

Impact of cell-free DNA screening on parental knowledge of fetal sex and disorders of sex development

OBJECTIVE

Discrepancies between cfDNA and ultrasound predicted fetal sex occur, possibly indicating disorders/differences of sex development (DSDs). Among expectant/recent parents, this study assessed cfDNA knowledge/use, fetal sex determination attitudes/behaviors, general knowledge of DSD, and possible psychological impact of discrepancy between fetal sex on cfDNA and ultrasound.

METHOD

Parents were surveyed about fetal sex determination methods, knowledge of cfDNA and DSD, distress related to possible cfDNA inaccuracy.

RESULTS

Of 916 respondents, 44% were aware of possible discrepancy between cfDNA and ultrasound, 22% were aware of DSD. 78% and 75% would be upset and worried, respectively, with results showing fetal sex discrepancy. Most (67%) revealed predicted fetal sex before delivery. 38% were offered cfDNA. Of those revealing fetal sex, 24% used cfDNA results, 71% ultrasound, and 7% both. cfDNA users were more frequently aware of possible discrepancy between cfDNA and ultrasound (76% vs 41%, P < .0001), but not of DSD (29% vs 23%, P = .29).

CONCLUSION

Fetal sex determination is favored, and cfDNA is frequently used for predicting fetal chromosomal sex. Many parents are unaware of possible discrepancies between cfDNA and ultrasound, and potential for DSD. Most would be distressed by discordant results. Accurate counseling regarding limitations cfDNA for fetal sex determination is needed.