Sex selection and non-invasive prenatal testing: A review of current practices, evidence, and ethical issues

Evaluation of pre-test counselling offered for non-invasive prenatal testing (NIPT) as a primary screening tool

The increasing popularity and expansion of non-invasive prenatal testing (NIPT) to screen for rare conditions beyond common trisomies prompts evaluation of pre-test counselling currently offered. We conducted a prospective survey to assess women's knowledge of NIPT in those who had undergone NIPT (study group) and those who were planning to have NIPT (control group). Out of the 189 questionnaires analysed, the study group did not show a higher knowledge score compared to the control group (P = 0.097). 44% misunderstood that NIPT can identify more conditions than invasive testing, 69.8% were unaware of the recommended need for nuchal translucency measurement and 52.6% were unaware of the possibility of incidental findings. 31% even considered discussing termination of pregnancy as one of the next steps if NIPT shows high risk for Down syndrome. This study shows that current pre-test counselling is inadequate. Service providers should address these knowledge gaps and assist women to make informed choices.Impact StatementWhat is already known on this subject? Pre-test counselling for non-invasive prenatal testing (NIPT) should be conducted to assist women in making an informed consent.What do the results of this study add? Our results show that a significant proportion of women are unaware of the limitations of NIPT.What are the implications of these findings for clinical practice and/or further research? Service providers should improve their pre-test counselling focusing on areas of knowledge deficiencies and misunderstanding on NIPT identified in this study.

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.

Understanding the relationship between maternity care providers and middle-class Chinese migrant women in the Netherlands: A qualitative study

OBJECTIVE

This study aims to provide insights into the formation and the quality of the maternity care provider-woman relationship between midwives, maternity care assistants and middle-class Chinese migrant women in the Netherlands.

DESIGN

online in-depth interviews addressing interpersonal trust, women's autonomy in shared decision making and culturally sensitive care PARTICIPANTS: 46 middle-class Chinese migrant women, 13 midwives and 12 maternity care assistants in the Netherlands FINDINGS: Midwives and maternity care assistants reported challenges interpreting the needs of middle-class Chinese migrant women in care practices while Chinese migrant women experienced receiving insufficient emotional support. Midwives and maternity care assistant tended to attribute women's different preferences for care to culture which reinforced difficulties of addressing women's needs. Middle-class Chinese migrant women experienced a lack of responsive care, feelings of being overlooked, being uncomfortable to express different opinions and challenges in developing autonomy in the shared decision-making process.

CONCLUSIONS

A trusting relationship, effective communication with maternity care providers, and a culturally sensitive and safe environment could be beneficial for middle-class migrant mothers. Chinese migrant women held ambivalent attitudes towards both traditional Chinese health beliefs and Dutch maternity care values. Each individual woman adopted the practice of the "doing the month" tradition to a different extent. This indicated the need for maternity care providers to recognize women's various needs for more responsive and individualized care, especially for first-time migrant mothers to negotiate their ways through the new healthcare system.

IMPLICATIONS FOR PRACTICE

We suggest a more proactive role for maternity care providers addressing the individual's subjectivity and preferences. Our findings are relevant and applicable for maternity care professionals conducting shared decision making with middle-class and highly educated migrant women living in Western contexts.

Women's health inequalities in 15 Muslim-populated countries: Evidence from population and mortality statistics

In this study, we examined health inequalities and the status of women as evidenced in the patterns of population and mortality statistics in fifteen Muslim-populated countries. Based on WHO data, female-to-male ratios were calculated to determine differential gender ratios of population and mortality, using Western gender patterns as a baseline. The socioeconomic contexts of the analysis were the percentage of women in parliaments data by OECD and the Gross National Income Per Capita PPP by the World Bank. The study results indicate that former USSR countries had fewer girls, suggesting gender selection, whilst fewer adult women in the Gulf States population indicate health inequalities. Female children's mortality was under-reported, inferring under-valuing girls. Higher female adult deaths in Egypt, Iran, and the Gulf States show greater discrimination. Women in the richest Muslim countries face more inequalities and less representation in Parliament. The implications of the study are discussed.

Position statement from the International Society for Prenatal Diagnosis on the use of non-invasive prenatal testing for the detection of fetal chromosomal conditions in singleton pregnancies

What is already known about this topic?

What does this study add?

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.

Expanded Non-invasive Prenatal Testing (NIPT) : Can the Child's Right to an Open Future Help Set the Scope?

Expanded non-invasive prenatal testing (NIPT) has provoked ethical concerns about its justifiable scope. In this paper, we evaluate the role of the child's right to an open future in setting the scope of NIPT. This 'open future principle' has been cited in arguments both limiting and expanding parental freedoms. This moral right holds that adult autonomy rights which children cannot yet exercise should nonetheless be protected until they can. Its purpose is to protect the future autonomy of the child as a future adult. Several authors have extended this rationale from child to fetus. However, the right was not anticipated to apply to the fetus, a non-legal entity in many jurisdictions. The aim of this paper is to reconsider whether this principle is useful to help deliberate the scope of NIPT. We find that extending the open future principle to delineate the scope of NIPT is theoretically flawed. We contend that in the prenatal context its value primarily lies with counselling for prenatal screening where it can be used to encourage parents' reflection on the implications of knowing for the sake of knowing on their future children and their relationship with them.

Non-Invasive Prenatal Testing for "Non-Medical" Traits: Ensuring Consistency in Ethical Decision-Making

The scope of noninvasive prenatal testing (NIPT) could expand in the future to include detailed analysis of the fetal genome. This will allow for the testing for virtually any trait with a genetic contribution, including "non-medical" traits. Here we discuss the potential use of NIPT for these traits. We outline a scenario which highlights possible inconsistencies with ethical decision-making. We then discuss the case against permitting these uses. The objections include practical problems; increasing inequities; increasing the burden of choice; negative impacts on the child, family, and society; and issues with implementation. We then outline the case for permitting the use of NIPT for these traits. These include arguments for reproductive liberty and autonomy; questioning the labeling of traits as "non-medical"; and the principle of procreative beneficence. This summary of the case for and against can serve as a basis for the development of a consistent and coherent ethical framework.

Use and misuse of ultrasound in obstetrics with reference to developing countries

Maternal and neonatal health is one of the main global health challenges. Every day, approximately 800 women and 7,000 newborns die due to complications during pregnancy, delivery, and neonatal period. The leading causes of maternal death in sub-Saharan Africa are obstetric hemorrhage (28.8%), hypertensive disorders in pregnancy (22.1%), non-obstetric complications (18.8%), and pregnancy-related infections (11.5%). Diagnostic ultrasound examinations can be used in a variety of specific circumstances during pregnancy. Because adverse outcomes may also arise in low-risk pregnancies, it is assumed that routine ultrasound in all pregnancies will enable earlier detection and improved management of pregnancy complications. The World Health Organization (WHO) estimated in 1997 that 50% of developing countries had no access to ultrasound imaging, and available equipment was outdated or broken. Unfortunately, besides all the exceptional benefits of ultrasound in obstetrics, its inappropriate use and abuse are reported. Using ultrasound to view, take a picture, or determine the sex of a fetus without a medical indication can be considered ethically unjustifiable. Ultrasound assessment when indicated should be every woman's right in the new era. However, it is still only a privilege in some parts of the world. Investment in both equipment and human resources has been clearly shown to be cost-effective and should be an obligatory step in the improvement of health care. Well-developed health systems should guide developing countries, creating principles for the organization of the health system with an accent on the correct, legal, and ethical use of diagnostic ultrasound in pregnancy to avoid its misuse. The aim of the article is to present the importance of correct and appropriate use of ultrasound in obstetrics and gynecology with reference to developing countries.

Inclusion of sex chromosomes in noninvasive prenatal testing in Asia, Australia, Europe and the USA: A survey study

OBJECTIVE

To examine the extent to which sex chromosomes are included in current noninvasive prenatal testing (NIPT) and the reporting practices with respect to fetal chromosomal sex and sex chromosome aberrations (SCAs), in addition to an update on the general implementation of NIPT.

METHOD

A questionnaire addressing the research objectives was distributed by email to fetal medicine and clinical genetics experts in Asia, Australia, Europe and the USA.

RESULTS

Guidelines on NIPT are available in the majority of the included countries. Not all existing guidelines address reporting of fetal chromosomal sex and SCAs. In most settings, NIPT frequently includes sex chromosomes (five Australian states, China, Hong Kong, Israel, Singapore, Thailand, USA and 23 of 31 European countries). This occurs most often by default or when parents wish to know fetal sex. In most settings, a potential SCA is reported by stating the risk hereof as "low" or "high" and/or by naming the SCA. Less than 50% of all pregnant women receive NIPT according to respondents from three Australian states, China, Israel, Singapore, Thailand and 24 of 31 European countries. However, this percentage, the genomic coverage of NIPT and its application as primary or secondary screening vary by setting.

CONCLUSION

In most of the studied countries/states, NIPT commonly includes sex chromosomes. The reporting practices concerning fetal chromosomal sex and SCAs are diverse and most commonly not addressed by guidelines. In general, NIPT is variably implemented across countries/states.

Klinefelter Syndrome: What should we tell prospective parents?

Klinefelter syndrome (KS) or 47,XXY is the most common sex chromosome aneuploidy (SCA), occurring at a prevalence of 1 in 600 male pregnancies. Historically, only 25% of individuals with KS came to medical attention, for a range of issues across the life course including under-virilisation at birth, developmental and social concerns in childhood, absence, delay or arrest of puberty in adolescence or infertility in adulthood. Our understanding of the phenotypic spectrum of KS has been largely influenced by this ascertainment bias. With increasing uptake of antenatal noninvasive prenatal testing (NIPT), a corresponding increase in identification of KS has been documented. Population-based longitudinal data from infancy to adulthood on these individuals is lacking, which impedes balanced antenatal genetic counselling and raises issues for prospective parents and clinicians alike.

Ethical issues associated with prenatal screening using non-invasive prenatal testing for sex chromosome aneuploidy

Prenatal screening for sex chromosome aneuploidies (SCAs) is increasingly available through expanded non-invasive prenatal testing (NIPT). NIPT for SCAs raises complex ethical issues for clinical providers, prospective parents and future children. This paper discusses the ethical issues that arise around NIPT for SCAs and current guidelines and protocols for management. The first section outlines current practice and the limitations of NIPT for SCAs. It then outlines key guidelines before discussing the ethical issues raised by this use of NIPT. We conclude that while screening for SCAs should be made available for people seeking to use NIPT, its implementation requires careful consideration of what, when and how information is provided to users.

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions

BACKGROUND

To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT).

METHODS

Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ² test for trend, with p < 0.05 considered significant.

RESULTS

46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001).

CONCLUSION

Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.

Maternal Xp22.31 copy-number variations detected in non-invasive prenatal screening effectively guide the prenatal diagnosis of X-linked ichthyosis

Background and aims: X-linked ichthyosis (XLI) is a common recessive genetic disease caused by the deletion of steroid sulfatase (STS) in Xp22.31. Maternal copy-number deletions in Xp22.31 (covering STS) can be considered an incidental benefit of genome-wide cell-free DNA profiling. Here, we explored the accuracy and clinical value of maternal deletions in Xp22.31 during non-invasive prenatal screening (NIPS).

Materials and methods: We evaluated 13,156 pregnant women who completed NIPS. The maternal deletions in Xp22.31 revealed by NIPS were confirmed with maternal white blood cells by chromosome microarray analysis (CMA) or copy-number variation sequencing (CNV-seq). Suspected positive women pregnant with male fetuses were informed and provided with prenatal genetic counseling.

Results: Nineteen maternal deletions in Xp22.31 covering STS were detected by NIPS, which were all confirmed, ranging in size from 0.61 to 1.77 Mb. Among them, eleven women with deletions in male fetuses accepted prenatal diagnoses, and finally nine cases of XLI were diagnosed. The nine XLI males had differing degrees of skin abnormalities, and of them, some male members of ten families had symptoms associated with XLI.

Conclusion: NIPS has the potential to detect clinically significant maternal X chromosomal CNVs causing XLI, which can guide the prenatal diagnosis of X-linked ichthyosis and reflect the family history, so as to enhance pregnancy management as well as children and family members’ health management.

Perceptions towards sex selection among Jordanian population: A survey study

Sex selection is becoming a more common practice in the society and worldwide. The current study aimed to examine the perceptions about sex selection options and possible association with sociodemographic factors and relevant characteristics. The study was a cross-sectional survey of adults in Jordan in January and February 2020 using a self-administered questionnaire. Results showed that 40.1% of respondents preferred male gender when having a child, 22.4% of respondents preferred the male gender when having a child, even if they have had children of both genders, and 71.3% preferred having children from both genders. On the other hand, 58.8% of participants preferred a male gender when there is one chance to conceive via assisted reproduction technologies. Also, among participants, 66% thought that sex selection is religiously acceptable, yet 78.0% did not support of the sex selection idea. The above factors were significantly associated with several sociodemographic variables such as gender, marital status, education, career, and place of residence, but not income. In conclusion, the current study shed a light on preferences towards sex selection in a large cohort to better understand the perception and attitude of the population towards this practice.

Video education about genetic privacy and patient perspectives about sharing prenatal genetic data: a randomized trial

BACKGROUND

Laboratories offering cell-free DNA often reserve the right to share prenatal genetic data for research or even commercial purposes, and obtain this permission on the patient consent form. Although it is known that nonpregnant patients are often reluctant to share their genetic data for research, pregnant patients' knowledge of, and opinions about, genetic data privacy are unknown.

OBJECTIVE

We investigated whether pregnant patients who had already undergone cell-free DNA screening were aware that genetic data derived from cell-free DNA may be shared for research. Furthermore, we examined whether pregnant patients exposed to video education about the Genetic Information Nondiscrimination Act-a federal law that mandates workplace and health insurance protections against genetic discrimination-were more willing to share cell-free DNA-related genetic data for research than pregnant patients who were unexposed.

STUDY DESIGN

In this randomized controlled trial (ClinicalTrials.gov Identifier: NCT04420858), English-speaking patients with singleton pregnancies who underwent cell-free DNA and subsequently presented at 17 0/7 to 23 6/7 weeks of gestation for a detailed anatomy scan were randomized 1:1 to a control or intervention group. Both groups viewed an infographic about cell-free DNA. In addition, the intervention group viewed an educational video about the Genetic Information Nondiscrimination Act. The primary outcomes were knowledge about, and willingness to share, prenatal genetic data from cell-free DNA by commercial laboratories for nonclinical purposes, such as research. The secondary outcomes included knowledge about existing genetic privacy laws, knowledge about the potential for reidentification of anonymized genetic data, and acceptability of various use and sharing scenarios for prenatal genetic data. Eighty-one participants per group were required for 80% power to detect an increase in willingness to share data from 60% to 80% (α=0.05).

RESULTS

A total of 747 pregnant patients were screened, and 213 patients were deemed eligible and approached for potential study participation. Of these patients, 163 (76.5%) consented and were randomized; one participant discontinued the intervention, and two participants were excluded from analysis after the intervention when it was discovered that they did not fulfill all eligibility criteria. Overall, 160 (75.1%) of those approached were included in the final analysis. Most patients in the control group (72 [90.0%]) and intervention (76 [97.4%]) group were either unsure about or incorrectly thought that cell-free DNA companies could not share prenatal genetic data for research. Participants in the intervention group were more likely to incorrectly believe that their prenatal genetic data would not be shared for nonclinical purposes than participants in the control group (28.8% in the control group vs 46.2% in the intervention; P=.03). However, video education did not increase participant willingness to share genetic data in multiple scenarios. Non-White participants were less willing than White participants to allow sharing of genetic data specifically for academic research (P<.001).

CONCLUSION

Most participants were unaware that their prenatal genetic data may be used for nonclinical purposes. Pregnant patients who were educated about the Genetic Information Nondiscrimination Act were not more willing to share genetic data than those who did not receive this education. Surprisingly, video education about the Genetic Information Nondiscrimination Act led patients to falsely believe that their data would not be shared for research, and participants who identified as racial minorities were less willing to share genetic data. New strategies are needed to improve pregnant patients' understanding of genetic privacy.

Does foetal gender influence maternal thyroid parameters in pregnancy?

Objective

It is unknown if foetal gender influences maternal thyroid function during pregnancy. We therefore investigated the prevalence of thyroid disorders and determined first-trimester TSH reference ranges according to gender.

Methods

A cross-sectional study involving 1663 women with an ongoing pregnancy was conducted. Twin and assisted pregnancies and l-thyroxine or antithyroid treatment before pregnancy were exclusion criteria. Serum TSH, free T4 (FT4) and thyroid peroxidase antibodies (TPOAb) were measured at median (interquartile range; IQR) 13 (11-17) weeks of gestation. Subclinical hypothyroidism (SCH) was present when serum TSH levels were >3.74 mIU/L with normal FT4 levels (10.29-18.02 pmol/L), and thyroid autoimmunity (TAI) was present when TPOAb were ≥60 kIU/L.

Results

Eight hundred and forty-seven women were pregnant with a female foetus (FF) and 816 with a male foetus (MF). In women without TAI and during the gestational age period between 9 and 13 weeks (with presumed high-serum hCG levels), median (IQR range) serum TSH in the FF group was lower than that in the MF group: 1.13 (0.72-1.74) vs 1.24 (0.71-1.98) mIU/L; P = 0.021. First-trimester gender-specific TSH reference range was 0.03-3.53 mIU/L in the FF group and 0.03-3.89 mIU/L in the MF group. The prevalence of SCH and TAI was comparable between the FF and MF group: 4.4% vs 5.4%; P = 0.345 and 4.9% vs 7.5%; P = 0.079, respectively.

Conclusions

Women pregnant with an MF have slightly but significantly higher TSH levels and a higher upper limit of the first-trimester TSH reference range, compared with pregnancies with a FF. We hypothesise that this difference may be related to higher hCG levels in women pregnant with a FF, although we were unable to measure hCG in this study. Further studies are required to investigate if this difference has any clinical relevance.

Fetal information as shared information: using NIPT to test for adult-onset conditions

The possibilities of non-invasive prenatal testing (NIPT) are expanding, and the use of NIPT for adult-onset conditions may become widely available in the near future. If parents use NIPT to test for these conditions, and the pregnancy is continued, they will have information about the child's genetic predisposition from birth. In this paper, we argue that prospective parents should be able to access NIPT for an adult-onset condition, even when they have no intention to terminate the pregnancy. We begin by outlining the arguments against testing in such a situation, which generally apply the same considerations that apply in the predictive testing of a minor to the fetus in utero. We then contend, firstly, that there are important practical considerations that support availability of testing for prospective parents regardless of their stated intentions. Secondly, we object to the ethical equation of a fetus in utero with a minor. We base our analysis on a view of pregnancy that conceptualises the fetus as a part of the gestational parent, as opposed to the more common 'container' model of pregnancy. We suggest that fetal information is best conceptualised as shared information between the gestational parent and future child. Thus, it should be approached in similar ways as other kinds of shared information (such as genetic information with implications for family members), where a person has a claim over their own information, but should be encouraged to consider the interests of other relevant parties.

What are the ethical issues involved in noninvasive prenatal testing in Japan?

AIMS

Noninvasive prenatal testing (NIPT) of pregnant women has been performed worldwide since 2011, and it is currently performed in more than 90 countries. However, the rate of adoption in Japan remains at less than 2%. This review seeks to identify the ethical and practical issues surrounding noninvasive prenatal screening-including the purpose of the test, its pros and cons, issues surrounding fair treatment, and social factors-to better understand why the adoption rate remains low.

METHODS

This study examines the complex ethical issues surrounding noninvasive prenatal testing, including the purpose of the test, its pros and cons, issues related to fair treatment, and social factors.

RESULTS

Although cell-free DNA analysis for common fetal trisomies using maternal blood is highly accurate, lack of access to such testing and discriminatory attitudes in society remain important barriers. Personal choices such as whether to undergo noninvasive prenatal screening and whether to continue a pregnancy are sometimes criticized by those who believe that it leads to the "selection of life" or discrimination against people with disabilities.

CONCLUSIONS

Obstetrics has changed dramatically in recent years, and prenatal diagnosis technology has also advanced. To keep up with these advances, better information should be provided to ensure the public has a more nuanced understanding of the screening beyond the overused argument that it leads to "selection of life."

Sex ratios at birth in Australia according to mother's country of birth: A national study of all 5 614 847 reported live births 1997-2016

Objectives

Son preference and sex selective practices have resulted in a deficit of girls in several countries, primarily across Asia. Emerging evidence indicates that son preference survives migration to Western high-income countries. The objective of this study was to assess male-to-female (M/F) ratios at birth per mother’s country of birth in Australia 1997–2016, in total and by parity, and by states/territories and over time.

Methods

Data for this national population-based cross-sectional study were obtained from the National Perinatal Data Collection (NPDC) and included all live births in Australia 1997–2016 (N = 5 614 847). M/F ratios with 95% Confidence Intervals were estimated.

Results

The M/F ratio for births to Australian-born mothers was within the expected range (1.03–1.07) regardless of parity and time period. M/F ratios were elevated above the expected range for births to mothers born in China in the total sample (M/F ratio 1.084, 95% confidence interval 1.071–1.097) and at parity 2 (1.175, 1.120–1.231), and for births to mothers born in India at parity 2 (1.146, 1.090–1.204). Parity 2 births were the most consistently male-biased across time. Across states, elevated M/F ratios were identified for both groups in New South Wales (China parity 2: 1.182, 1.108–1.260; India parity 2: 1.182, 1.088–1.285), for births to Chinese-born mothers in Victoria (total births: 1.097, 1.072–1.123; parity 1: 1.115, 1.072–1.159) and Australian Capital Territory (total births: 1.189, 1.085–1.302) and births to Indian-born mothers Western Australia (parity 2: 1.307, 1.122–1.523).

Conclusions

Son preference persists in some immigrant communities after migration to Australia. The consistent pattern of elevated M/F ratios across the larger states indicates that sex imbalances at birth are largely independent of restrictiveness of local abortion laws. Drivers and consequences of son preference in Western high-income settings should be explored to further promote gender equality, and to strengthen support for women who may be vulnerable to reproductive coercion.

The Emergence and Global Spread of Noninvasive Prenatal Testing

Since its introduction in 2011, noninvasive prenatal testing (NIPT) has spread rapidly around the world. It carries numerous benefits but also raises challenges, often related to sociocultural, legal, and economic contexts. This article describes the implementation of NIPT in nine countries, each with its own unique characteristics: Australia, Canada, China and Hong Kong, India, Israel, Lebanon, the Netherlands, the United Kingdom, and the United States. Themes covered for each country include the structure of the healthcare system, how NIPT is offered, counseling needs and resources, and cultural and legal context regarding disability and pregnancytermination. Some common issues emerge, including cost as a barrier to equitable access, the complexity of decision-making about public funding, and a shortage of appropriate resources that promote informed choice. Conversely, sociocultural values that underlie the use of NIPT vary greatly among countries. The issues described will become even more challenging as NIPT evolves from a second-tier to a first-tier screening test with expanded use.

Noninvasive prenatal screening for fetal sex chromosome aneuploidies

INTRODUCTION

Sex chromosome aneuploidies (SCAs) are among the most common chromosome abnormalities observed in humans. Manifestations include low fertility, infertility, delayed language development, and dysfunction in motor development. Noninvasive prenatal screening (NIPS) based on cell-free fetal DNA from the peripheral blood of pregnant women is increasingly used for the screening of fetal chromosome abnormalities, including screening for fetal gender and fetal sex chromosome aneuploidy. A systematic review of the literature about NIPS for SCAs is needed.

AREAS COVERED

This review evaluated a vast array of published studies focusing on the clinical significance, detection methods, performance of NIPS for SCAs, and the management of positive SCA results following screening with the aim of facilitating a comprehensive and systematic understanding of NIPS for SCAs.

EXPERT COMMENTARY

Looking forward, NIPS is expected to become the primary screening test for common aneuploidies as well as other chromosome abnormalities, including some micro-deletions and micro-duplications, with the potential to transition from a screening test to a prenatal diagnosis method. Ultimately, the goal is to provide a safe and accurate method for increasing early diagnosis to improve long-term outcomes for the SCA patients and families by well- informed health care providers.

Development of a Specific Monoclonal Antibody to Detect Male Cells Expressing the RPS4Y1 Protein

Hemophilia is an X-linked recessive bleeding disorder. In pregnant women carrier of hemophilia, the fetal sex can be determined by non-invasive analysis of fetal DNA circulating in the maternal blood. However, in case of a male fetus, conventional invasive procedures are required for the diagnosis of hemophilia. Fetal cells, circulating in the maternal bloodstream, are an ideal target for a safe non-invasive prenatal diagnosis. Nevertheless, the small number of cells and the lack of specific fetal markers have been the most limiting factors for their isolation. We aimed to develop monoclonal antibodies (mAbs) against the ribosomal protein RPS4Y1 expressed in male cells. By Western blotting, immunoprecipitation and immunofluorescence analyses performed on cell lysates from male human hepatoma (HepG2) and female human embryonic kidney (HEK293) we developed and characterized a specific monoclonal antibody against the native form of the male RPS4Y1 protein that can distinguish male from female cells. The availability of the RPS4Y1-targeting monoclonal antibody should facilitate the development of novel methods for the reliable isolation of male fetal cells from the maternal blood and their future use for non-invasive prenatal diagnosis of X-linked inherited disease such as hemophilia.

Non-invasive prenatal diagnosis and screening for monogenic disorders

Cell-free fetal DNA (cffDNA) can be detected in the maternal circulation from 4 weeks gestation, and is present with cell-free maternal DNA at a level of between 5 % and 20 %. Cell-free DNA (cfDNA) can be extracted from a maternal blood sample and, although it is not possible to separate the fetal from the maternal cfDNA, it has enabled non-invasive prenatal diagnosis (NIPD) without the associated miscarriage risk that accompanies invasive testing. NIPD for monogenic diseases was first reported in 2000 and since then there have been many proof of principle studies showing how analysis of cfDNA can provide a definitive diagnosis early in pregnancy for a wide range of single gene diseases. Testing for a number of these diseases has been available in the UK National Health Service (NHS) since 2012. This review highlights the main techniques that are being used for NIPD and discusses the technical limitations of the methods, as well as the advances that are being made to overcome some of the issues. NIPD is technologically challenging for a number of reasons. Firstly, because it requires the detection of low level fetal variants in a high maternal background. For de novo and paternally-inherited variants this has been achieved through the use of techniques such as next-generation sequencing (NGS) and digital PCR to detect variants in the cffDNA that are not present in the maternal cfDNA. However, for maternally-inherited variants this is much more challenging and relies on dosage-based techniques to detect small differences in the levels of mutant and wild-type alleles. Alongside the technical advances that are making NIPD more widely available in both the public healthcare and commercial settings, it is crucial that we continue to monitor the social and ethical impact to ensure that patients are being offered safe and accurate testing.

Sex selection and non-invasive prenatal testing: A review of current practices, evidence, and ethical issues

Non-invasive prenatal testing (NIPT) can determine the sex of the fetus very accurately and very early in gestation. There are concerns that the ease, timing, and accuracy of NIPT sex determination will facilitate sex-selective termination of pregnancy (TOP). Here, we review current practices, the evidence for a link between NIPT and sex-selective TOP, and associated ethical issues. Sex-selective TOP, usually motivated by son preference, has had serious demographic consequences in countries such as India and China. Currently, ultrasound is the primary method by which parents determine the sex of the fetus. The diffusion of ultrasound technology has had a direct impact on the rates of sex-selective TOP. Although NIPT is currently more costly, it is feasible that increased uptake of this technology could have a similar effect. Partly because NIPT is a relatively recent development in prenatal screening, there is little data on the impact of NIPT on sex selection practices. Evidence that NIPT is playing a role in sex-selective TOP remains largely anecdotal. Further research is required to assess and quantify TOP resulting from NIPT sex determination. The use of these technologies for sex selection raises a number of ethical issues, in addition to practical demographic consequences.