Prenatal gender determination and the diagnosis of genital anomalies

Performance of ultrasound in detecting fetal hypospadias during pregnancy: a pooled analysis

Background

Opinions regarding the role and value of ultrasound in the diagnosis of prenatal hypospadias are diverse. Although hypospadias is not a fatal malformation, a higher degree of severity exerts a significant impact on children's physiology and psychology. On the other hand, hypospadias may be accompanied by accompanying anomalies, syndromic conditions, and fetal growth restriction (FGR). This study aimed to systematically assess the value of ultrasound in the prenatal diagnosis of hypospadias.

Methods

In the systematic review and meta-analysis, we searched PubMed, Web of Science, Scopus, Embase, and China National Knowledge Infrastructure (CNKI) databases until June 30, 2024. The key terms included: hypospadias, ultrasound, and prenatal diagnosis. Studies were assessed following the eligibility criteria, and the data from the included studies were extracted through a standardized protocol. The primary outcomes focused on the positive predictive value (PPV), accuracy, sensitivity, and specificity of ultrasound for detecting fetal hypospadias. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) scale was used to assess the risk of bias. The PPV was calculated using the bootstrap method. When five or fewer studies were pooled, a random-effect model based on the Hartung-Knapp-Sidik-Jonkman (HKSJ) method was used as a meta-analysis strategy to evaluate the overall effect. Sensitivity and specificity were pooled using a Summary Receiver Operating Characteristic (SROC) curve. The protocol was registered with PROSPERO (CRD42024586840).

Findings

A total of nine studies with 600 cases were included in the systematic review. The pooled median gestational age of the included studies was 27.64 ± 3.15 weeks. The overall PPVs of two-dimensional ultrasound (2DUS) in diagnosing fetal hypospadias and external genital malformations were 81% (95% confidence interval (CI): 77%-85%) and 88% (95% CI: 86%-91%), respectively. Upon in-depth analysis of the five studies, the accuracy of 2DUS combined with three-dimensional ultrasound (3DUS) was 84% (95% CI: 78%-89%), and that of 2DUS alone was 74% (95% CI: 69%-78%). The difference between the two methods was 10%. The pooled sensitivity of 2DUS combined with 3DUS in diagnosing fetal hypospadias was 86% (95% CI: 79%-93%), the specificity was 77% (95% CI: 69%-86%), and the area under the curve (AUC) was 0.86 (95% CI: 0.83-0.89).

Interpretation

This is the first diagnostic meta-analysis to comprehensively evaluate the detection of fetal hypospadias using ultrasound during pregnancy, indicating that ultrasound is indeed of significant value in the prenatal diagnosis of hypospadias. More research is needed to validate and enhance current research findings and offer more comprehensive guidance for future clinical practice.

Funding

This work was supported by the Natural Science Foundation Project of Chongqing, Chongqing Science and Technology Commission (CSTB2022NSCQ-MSX1001) and the Program for Youth Innovation in Future Medicine, Chongqing Medical University (W0109).

Preference and Disclosure of Fetal Gender to Pregnant Women during Prenatal Ultrasonography in South South Nigeria

BACKGROUND

Ultrasound scan (USS) in pregnancy has become a common diagnostic tool used in the assessment of pregnancy in recent time. In the course of routine pregnancy assessment using USS, some pregnant women will request to know the sex of their unborn babies. Their reasons for wanting to know the gender of their baby could be either for social reason like planning for an unborn child or their desire for a preferred gender.

AIM

The aim of the study was to evaluate gender preferences and disclosure of foetal sex at prenatal USS.

METHODS

This was a cross-sectional study conducted at the antenatal clinic of Central Hospital Agbor, Delta State, Nigeria. A total of 235 consecutive consenting women who came for antenatal care (ANC) registration were recruited for the study after obtaining their informed written consent. Questionnaire was used to seek for their sociodemographic characteristics, preference and desires for foetal gender disclosure, reasons for gender disclosure, and awareness of USS accuracy for gender determination.

RESULTS

The desire to know the sex of baby was high (99.6%). The major reason for wanting to know the sex of baby was to plan for the unborn child (47.7%) and maternal curiosity (37.0%). Majority of the women (57.4%) had no gender preference. Sixty percent (60%) were not aware that USS sex diagnosis could be wrong.

CONCLUSION

There is a strong desire by pregnant women to know the sex of their babies at routine USS. Considering the fact that many of the women were not aware that there could be wrong diagnosis at prenatal ultrasound, it is suggested that adequate counselling be given before fetal sex disclosure.

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.

The Development of Normal Fetal External Genitalia Throughout Gestation

In this review, we describe normal development of fetal genitalia throughout gestation as well as the identification of normal male and female genitalia on ultrasound. We use abnormal and ambiguous genitalia as illustrative tools to assist with the identification of normal genitalia and recognition of some of the most common abnormalities in external genitalia development.

Fetal sex discordance

Fetal sex discordance is an entity that is becoming more frequent due to the expansion of the cfDNA for prenatal diagnosis. Its incidence can be estimated in 1/1500-2000 pregnancies, a frequency as high as that of some common chromosomopathies. The causes of this phenomenon are multiple and diverse, ranging from laboratory errors to important pathologies such as disorders of sexual differentiation. The management of a case of fetal sex discordance must be structured, starting with the review of the clinical history and the tests performed, and may require the performance of invasive tests to reach a diagnosis. Prevention through adequate pretest counseling and ultrasound confirmation can help to reduce its incidence.

Discordant fetal sex on NIPT and ultrasound

Prenatal diagnosis of sex discordance is a relatively new phenomenon. Prior to cell-free DNA testing, the diagnosis of a disorder of sexual differentiation was serendipitous, either through identification of ambiguous genitalia at the midtrimester morphology ultrasound or discovery of genotype-phenotype discordance in cases where preimplantation genetic diagnosis or invasive prenatal testing had occurred. The widespread integration of cfDNA testing into modern antenatal screening has made sex chromosome assessment possible from 10 weeks of gestation, and discordant fetal sex is now more commonly diagnosed prenatally, with a prevalence of approximately 1 in 1500-2000 pregnancies. Early detection of phenotype-genotype sex discordance is important as it may indicate an underlying genetic, chromosomal or biochemical condition and it also allows for time-critical postnatal treatment. The aim of this article is to review cfDNA and ultrasound diagnosis of fetal sex, identify possible causes of phenotype-genotype discordance and provide a systematic approach for clinicians when counseling and managing couples in this circumstance.

The ultrasound identification of fetal gender at the gestational age of 11-12 weeks

Introduction

The early prenatal identification of fetal gender is of great importance. Accurate prenatal identification is currently only possible through invasive procedures. The present study was conducted to determine the accuracy and sensitivity of ultrasound fetal gender identification.

Materials and Methods

The present cross-sectional study was conducted on 150 women in their 11^th and 12^th weeks of pregnancy in Hamadan in 2014. Ultrasound imaging performed in the 11^th and 12^th weeks of pregnancy for fetal gender identification identified the fetus either as a girl, a boy, or as a "gender not assigned." Frequency, sensitivity, specificity, positive and negative predictive values, and accuracy of the gender identification was assessed using SPSS version 20. The significant level was 0.05 in all analyses.

Results

Of the total of 150 women, the gender was identified as female in 32 (21.3%), as male in 65 (43.3%), and not assigned in 53 (35.3%); overall, gender identification was made in 64.6% of the cases. A total of 57 male fetuses were correctly identified as boys, and 8 female fetuses were wrongly identified as boys. As for the female fetuses, 31 were correctly identified as girls, and 1 was wrongly identified as a boy. The positive predictive value for the ultrasound imaging gender identification was 87.6% for the male fetuses and 96.8% for the female fetuses.

Conclusion

The present study had a much higher gender identification accuracy compared to other studies. The final success of fetal gender identification was about 91% in the 11^th and 12^th weeks of pregnancy.

First-trimester determination of fetal gender by ultrasound: measurement of the ano-genital distance

INTRODUCTION

Early ultrasound fetal sex determination is of obvious interest, particularly in the context of X-linked diseases. In the human, the anogenital distance, i.e., the distance between the caudal end and the base of the genital tubercule is sexually dimorphic. This difference is apparent from 11 weeks of gestation. The aim of this prospective study was to evaluate the accuracy of anogenital distance measurement during the first trimester ultrasound in the early determination of fetal gender.

MATERIALS AND METHODS

Fetal gender was assessed by ultrasound in 310 singleton pregnancies at 11-14 weeks of gestation. The optimal cut-off was determined by the minimal p-value technic and validated using bootstrap simulation.

RESULTS

310 women were included. A cut-off of 4.8mm was determined to predict male (≥4.8mm) or female (<4.8mm) fetuses. Sex was correctly determined for 87% of the males and 89% of the females. The inter-observer variability was excellent.

CONCLUSION

This study presents a new sonographic sign for early fetal sex determination that has not been previously explored. It appears to be an accurate tool but it requires further validation in larger series.

Perception of male gender preference among pregnant igbo women

Background:

Male gender preference is a dominant feature of Igbo culture and could be the reason behind women seeking fetal gender at ultrasound.

Aim:

The aim of this study is to investigate the perception of prenatal ultrasound patients of male gender preference in a patriarchal and gender sensitive society.

Subjects and Methods:

The study was a cross-sectional survey, which targeted pregnant women who presented for prenatal ultrasound at four selected hospitals in Anambra State. A convenience sample size of 790 pregnant women constituted the respondents. The data collection instrument was a 13-item semi-structured self-completion questionnaire designed in line with the purpose of the study. Descriptive and inferential statistical analyses were carried out with statistical significance being considered at P < 0.05.

Results:

Most of the women (88.4%, 698/790) were aware that fetal gender can be determined during the prenatal ultrasound while just over half of them (61.0%, 482/790) wanted fetal gender disclosed to them during prenatal ultrasound. More than half (58.6%, 463/790) of the women desired to have male babies in their present pregnancies while 20.1% (159/790) desired female babies and 21.3% (168/790) did not care if the baby was male or female. Some of the women (22.2%, 175/790) wanted to have male babies in their present pregnancies for various reasons predominant of which was protecting their marriages and cementing their places in their husbands’ hearts. Male gender preference was strongly perceived. There was considerable anxiety associated with prenatal gender determination and moderate loss of interest in the pregnancy associated with disclosure of undesired fetal gender. Socio-demographic factors had significant influence on perception of male gender preference.

Conclusion:

Male gender preference is strongly perceived among Igbo women and its perception is significantly influenced by socio-demographic factors. Male gender preference may be responsible for Igbo women seeking fetal gender at ultrasound.

The accuracy of 2D ultrasound prenatal sex determination

Background:

Pregnant women have been curious about the sex of their unborn child. The advent of ultrasound, its application into medicine, and the revolutionary changes in its resolution and function has led to the ability to assign a sex to these unborn children, thereby allaying the anxiety of these women but with consequent emergent ethical, moral, psycho-social, and medico-legal issues. The objectives were to determine the accuracy of sonographic prenatal sex determination, perform binary classification test, and the impact it has, including mis-diagnosis.

Materials and Methods:

A prospective prenatal sonographic sex determination study on 205 consecutive consenting pregnant women aged 20-40 years in a private hospital in Benin between August 2010 and October 2011. Questionnaires were administered to these women before and after the scan and the women were told the sex of the fetuses and their feelings on the determined sex recorded. The sex at birth was confirmed and compared to the scan determined gender by their case note and telephone. Relevant discussions during the scan and later on were recorded on the questionnaires. The statistical package used was SPSS version 17 and binary classification tests were performed.

Results:

The sensitivity (98.2%) and binary classification components values of prenatal sex determination were high with the sensitivity of detecting a female higher than that of males. Two males were misdiagnosed as females. Most of the women were happy even when the sex differed from that which they desired.

Conclusion:

Prenatal sonographic sex determination has a high sensitivity index. Consequently we advocate its use prior to more invasive sex tests.

Prenatal management of disorders of sex development

Disorders of sex development (DSD) rarely present prenatally but, as they are very complex conditions, management should be directed by highly specialised medical teams to allow consideration of all aspects of diagnosis, treatment and ethical issues. In this brief review, we present an overview of the prenatal presentation and management of DSD, including the sonographic appearance of normal genitalia and methods of determining genetic sex, the prenatal management of pregnancies with the unexpected finding of genital ambiguity on prenatal ultrasound and a review of the prenatal management of pregnancies at high risk of DSD. As this is a rapidly developing field, management options will change over time, making the involvement of clinical geneticists, paediatric endocrinologists and urologists, as well as fetal medicine specialists, essential in the care of these complex pregnancies. The reader should also bear in mind that local social, ethical and legal aspects may also influence management.

A woman's decision to know the sex of her child prior to birth

Introduction

Advances in ultrasound technology have allowed sex determination to be offered to prospective parents during the anomaly scan visit in ultrasound departments. There has been much publicity recently with respect to terminations having been requested based on fetal sex. In other countries there are skewed male to female birth ratios due to ‘wrong sex’ termination, which is usually female. This study has been designed to determine the prevalence of women requesting sex identification and the accuracy of sex determination. Additionally, we have identified demographic and clinical factors, which may be associated with this decision.

Methods

Ethical approval was obtained from the North West Proportionate Review Board. The study included all 2780 women attending their anomaly scan at Salford Royal Hospital in 2009. From their medical records we have determined how many women requested sex identification, the sex that was predicted and the accuracy of this prediction. We also recorded the women's age, parity, race, religion, and past history of fertility problems.

Results

The results showed that 74% of women wanted to know the sex of their baby, of whom 1.8% were unable to be told because of the position of the fetus at the time of the scan. Sex determination was correct in 99.4% of cases and there was no significant difference between the identification of males and females. Factors that were significantly associated with an increased desire to know were, being younger ( < 30 years); multiparous; of Afro Caribbean, Eastern European or Chinese origin [chi squared < 0.05]. Jewish women were the group least likely to request the information (32%), along with women aged 41–47 with fertility problems (42%).

Conclusion

The prevalence, sensitivity and accuracy of ultrasound sex determination have been established in this study and subgroups identified that request this information.

Prenatal two- and three-dimensional imaging in two cases of severe penoscrotal hypospadias

We present the prenatal two- and three-dimensional (3D) ultrasound (US) findings in two cases of severe penoscrotal hypospadias. 3D sonography was used for better definition of ambiguous genitalia. The images were compared with postnatal clinical features. Despite hypospadias being the most common urogenital anomaly of male neonates, the diagnosis is often missed before birth. Performing prenatal ultrasound should include the study of genitals, not only determining the sex.

Improving obstetric estimation of outcomes of extremely premature neonates: an evolving challenge

AIMS

A clinically useful website at the US National Institutes of Child Health and Human Development (NICHD) uses an algorithm based on a recent publication to estimate peri-viable neonatal outcomes. This algorithm uses gestational age, ultrasound estimated fetal weight (EFW), fetal sex, and the use of antenatal corticosteroids as the basis for estimation of outcomes and when used after birth is superior to such estimation by gestational age alone. Because one might be tempted to use this algorithm with obstetric patients, we tested its clinical applicability.

METHODS

We reviewed the literature using search terms relating to the above clinical factors. Next, we gathered data from the website. The range of outcomes for neonates was then estimated using the uncertainty derived for these clinical factors before birth from the literature review and the NICHD website algorithm.

RESULTS

We found increased uncertainty for estimating outcomes, as a function of the greater uncertainty in knowledge of the clinical factors in obstetrics as opposed to neonatology.

CONCLUSIONS

The imprecision during the time before birth seriously restricts the obstetric use of the NICHD algorithm at this time. Refining the precision of the algorithm prior to birth is necessary.

Male gender as a favorable prognostic factor in pregnancies with enlarged nuchal translucency

OBJECTIVE

The aim of this study was to investigate the influence of fetal gender on pregnancy outcome in fetuses with enlarged nuchal translucency (NT).

METHODS

Pregnancy outcomes of all women who underwent an NT measurement at our institution between January 2000 and November 2007 were retrospectively reviewed. Separate analyses were performed for fetuses with normal and with enlarged (>or= 95(th) percentile) NT.

RESULTS

A normal NT was measured in 3637 males (51.4%) and 3435 females (48.6%). Of the fetuses with enlarged NT 365 were males (57.4%) and 271 females (42.6%) (P = 0.001). In this group a normal pregnancy outcome-of those pregnancies for which the outcome was known-was registered for 187/332 (56.3%) of the male fetuses and 98/249 (39.4%) of the female fetuses (P < 0.001; relative risk (RR) for adverse outcome for male gender, 0.72). Eighty percent of the chromosomally normal male fetuses with an enlarged NT had an uneventful pregnancy outcome; this increased to 90% when only the male fetuses with NT measurements >or= 95(th) percentile and < 99(th) percentile and normal karyotype were considered (RR for adverse outcome for male gender, 0.47).

CONCLUSION

In a population of fetuses with enlarged NT there are significantly more males. Male fetuses with enlarged NT and normal chromosomes have an almost two-fold greater chance of a favorable outcome than females. We believe that a minimal degree of NT enlargement in male fetuses without genetic or structural anomalies may be interpreted as a feature of accelerated growth or, alternatively, as a maturational delay of the cardiovascular system more common in males, leading to moderately increased nuchal fluid accumulation.

Disorders of sexual development

Disorders of sex development are medical conditions in which the development of chromosomal, gonadal, or anatomic sex varies from normal and may be incongruent with each other. This article primarily addresses the medical conditions where infants may be born with ambiguous genitalia leading to decisions with regard to gender assignment. The approach to investigations and diagnosis in the newborn period will be stressed within an interprofessional team. Policies with regard to surgery have developed, with techniques evolving and data emerging from long-term outcome studies. Current medical and surgical management are reviewed. Finally, a developmental approach to disclosure is presented.

Fetal genital anomalies: an aid to diagnosis

OBJECTIVE

To report our experience with the prenatal diagnosis of fetal genital anomalies and suggest a protocol for management.

METHODS

A retrospective review of all the cases with fetal genital anomalies or phenotype and genotype discrepancy identified by prenatal ultrasound.

RESULTS

Twenty cases with abnormal fetal genitalia and four with a phenotype and genotype discrepancy were diagnosed prenatally. Genital anomalies were rarely found in isolation, most were found in combination with renal or multiple structural anomalies. The etiology of abnormal genitalia was broad and included metabolic, chromosomal and genetic syndromes.

CONCLUSION

Prenatal detection of genital anomalies should stimulate a detailed ultrasound examination and determination of genotypic sex. Measurement of 17-OHP and Delta(4)-androstenedione or metabolites of the cholesterol pathway in the amniotic fluid and/or maternal urine may be helpful in making a definitive diagnosis. Identification of genital anomalies in fetuses with renal or multiple abnormalities can aid prenatal diagnosis, thereby facilitating accurate counseling of parents who are then in a better position to make informed choices.

Non-invasive fetal sex determination: impact on clinical practice

Prenatal fetal sex determination is undertaken in women at high risk of serious genetic disorders affecting a specific sex. Traditionally, this is undertaken by invasive testing, usually chorionic villus sampling, which carries a risk of miscarriage of around 1%. The identification of cell-free fetal DNA in the maternal circulation has allowed the development of 'non-invasive prenatal diagnostic tests', which permit fetal sex determination without risk to the pregnancy.

Prenatal diagnosis, sonographic findings and molecular genetic analysis of a 46,XX/46,XY true hermaphrodite chimera

OBJECTIVES

To present the prenatal diagnosis, sonographic findings and, molecular genetic analysis of a 46,XX/46,XY true hermaphrodite chimera and to review the literature.

CLINICAL SUBJECT AND METHODS

Amniocentesis was performed at 22 weeks' gestation because of sonographic diagnosis of ambiguous genitalia. Initial amniocentesis, repeat amniocentesis, and cordocentesis revealed a mixture of 46,XX cells and 46,XY cells. Polymorphic DNA marker analysis using the fetal and parental blood was applied to investigate the genetic origin of the chimera. A 3,625-g baby was delivered at 37 weeks' gestation with clitoromegaly, prominent labia majora, fusion of the labia, and an orifice of the urogenital sinus. A lymphangioma was noted over the right arm and was excised at age 3 days. Extraembryonic tissues and the infant's skin were cytogenetically and molecularly studied.

RESULTS

Initial amniocentesis, repeat amniocentesis, and cordocentesis revealed the karyotype of 46,XX[12]/46,XY[9], 46,XX[15]/46,XY[12], and 46,XX[27]/46,XY[15], respectively. The cytogenetic results of the extraembryonic tissues and skin were consistent with prenatal diagnosis. Informative sex chromosome and pericentromeric autosome markers demonstrated double paternal and single maternal genetic contributions.

CONCLUSIONS

Prenatal sonographic diagnosis of ambiguous genitalia should alert true hermaphroditism and prompt thorough genetic investigations. DNA marker analysis is helpful in delineation of true fetal chimerism as well as determination of its genetic origin in prenatally detected 46,XX/46,XY chromosome complement.

Practical management of the intersex infant

Intersex occurs when the appearance of the internal or external genitalia is at variance with normal development for either sex. The first question asked by, and of new parents in relation to their offspring is often "Is it a boy or a girl"? A rational approach, based on knowledge of normal prenatal sexual development, and based on a careful physical examination to guide further investigation, is required to reach a diagnosis. We briefly review prenatal sexual development to provide a background to the assessment of genital ambiguity in the newborn. Aspects of physical examination are discussed in detail, with reference to published normative data where possible. We provide a classification of genital ambiguity and an approach to differential diagnosis. We highlight some of the many syndromes associated with genital ambiguity, with reference to their genetic basis where possible. In 46,XX individuals, the commonest cause of genital ambiguity is congenital adrenal hyperplasia due to 21-hydroxylase deficiency; however, in 46,XY individuals the differential diagnosis is wide, and may remain unexplained, even after extensive investigation. Two algorithms are presented, one of which provides an initial approach based on the presence of a uterus and palpable gonads alone, and a second illustrating a comprehensive differential diagnosis of the undervirilised 46,XY individual. We discuss our approach to sharing information on the diagnosis and management with the parents and highlight the early involvement of an experienced multidisciplinary team. Finally, we consider current controversial issues relating to gender assignment and management of genital ambiguity.

Fetal cardiac anomalies and genetic syndromes

Cardiac anomalies may occur in isolation or can be part of a genetic syndrome. In this article, we describe some of the genetic syndromes commonly associated with cardiac anomalies where there are other sonographic features that may aid accurate prenatal diagnosis.