Cost-effectiveness analysis of carrier and prenatal genetic testing for X-linked hemophilia

Complication rates after chorionic villus sampling and midtrimester amniocentesis: A 7-year national registry study

PURPOSE

To assess the complication rates following chorionic villus sampling (CVS) and midtrimester amniocentesis in Taiwan.

METHODS

This is a national registry-based cohort study from Taiwan. We included all women with singleton pregnancies who received either CVS (n = 1409) or midtrimester amniocentesis (n = 250,566) during 2006-2012. We assessed preterm premature rupture of membranes (PPROM), intrauterine fetal demise (IUFD), infection and spontaneous abortion (SA) that occurred within fourteen days after the procedures. We also assessed the risks of preterm delivery and miscarriage before 24 gestational weeks after amniocentesis. These complications were collected from the Genetic Disease Database of the Ministry of Health and Welfare, Taiwan National Birth Certificate Registry, and the Taiwan National Health Insurance Database. Pearson χ² tests were used to compare the distributions between groups.

RESULTS

For patients who underwent midtrimester amniocentesis, the rates of PPROM, IUFD, infection and SA within fourteen days were 0.24%, 0.11%, 0.05%, and 0.05%, respectively. Women with a normal fetal karyotype had a preterm birth rate (<37 gestational weeks) of 9.38%. The miscarriage rate (<24 gestational weeks) was 0.68%, which was 0.22% higher than those who did not receive the invasive procedures (p < 0.0001). After CVS, the IUFD rate was 1.68%, and the SA rate within fourteen days was 0.77%.

CONCLUSION

The use of our large cohort demonstrated that the procedure-related complication rates were comparable to recent review or meta-analysis. This dataset might facilitate counselling in women who consider invasive genetic diagnostic procedures.

Preventing lives affected by hemophilia: A mixed methods study of the views of adults with hemophilia and their families toward genetic screening

Background

Genomic sequencing technologies have made the possibility of population screening for whole panels of genetic disorders more feasible than ever before. As one of the most common single gene disorders affecting the UK population, hemophilia is an attractive candidate to include on such screening panels. However, very little is known about views toward genetic screening amongst people with hemophilia or their family members, despite the potential for a wide range of impacts on them.

Methods

Twenty‐two in‐depth qualitative interviews were undertaken to explore the views of adults with hemophilia and their family members, recruited through the Haemophilia Society UK. These interviews were used to develop a survey, the Haemophilia Screening Survey (UK), which was distributed in paper and online format through the support group, receiving 327 returns between January and June 2018.

Results

Fifty‐seven per cent of the sample supported preconception carrier screening of the population for hemophilia, and 59% supported prenatal carrier screening. Key reasons for support included a desire to reduce pregnancy terminations and increase awareness of hemophilia. Despite support for screening however, 90% of the sample disagreed with pregnancy terminations for hemophilia.

Conclusions

Families and adults living with hemophilia are more supportive of screening for information and preparation purposes than to prevent boys with hemophilia from being born. A distinction was made between preventing the disease and preventing the lives of people with it, with support shown for the use of screening to achieve the former, but not at the expense of the latter.

Newborn screening for haemophilia: The views of families and adults living with haemophilia in the UK

INTRODUCTION

As genomic sequencing become more efficient and cost-effective, the number of conditions identified through newborn screening globally is set to dramatically increase. Haemophilia is a candidate condition; however, very little is known about the attitudes of the haemophilia community towards screening.

AIM

This study aimed to outline the perspectives of adults with haemophilia and their families towards newborn screening.

METHODS

A paper and online survey on screening were distributed to every family known to the Haemophilia Society UK. Data collection occurred between January and June 2018. In total, 327 participants completed the survey: 76% were a relative of a person with haemophilia and 24% had haemophilia themselves; 83% were living with haemophilia A and 17% with haemophilia B.

RESULTS

The vast majority supported newborn screening (77%) and preferred it to other forms of screening (preconception or prenatal). Participants supported newborn screening primarily because they viewed it as a means to facilitate early support and treatment, facilitate informed decisions about future pregnancies and prevent the "diagnostic odyssey." The 23% who did not support the screen did not associate these particular benefits with newborn screening.

CONCLUSION

Haemophilia emerged from this analysis as a condition that the vast majority of participants considered a "liveable" disability and one best suited to newborn screening programmes that could improve support to affected families rather than reduce the birth rate of affected children.

Prenatal diagnosis for haemophilia: the Thai experience

BACKGROUND

Haemophilia is a lifelong X-linked recessive inherited bleeding disorder. Since the haemophilia management in economically less-developed countries is inadequately provided, prevention of new cases of haemophilia is essentially required.

SUBJECTS AND METHODS

A total of 42 pregnancies in 37 women at risk for severe and moderate haemophilia (A = 33, B = 4) were enrolled. The prenatal diagnostic (PND) procedure was performed in 32 women, while 10 women refused further PND procedure after knowing their foetuses were female (n = 8) and male (n = 2). The foetal specimen was obtained through chorionic villus sampling (n = 14), amniocentesis (n = 1) and cordocentesis (n = 17). The status of haemophilia was determined using informative RFLP markers and inversion of intron 22 of the F8 gene, and/or foetal FVIII:C or FIX:C.

RESULTS

The final diagnosis revealed normal males (n = 18), haemophilia A males (n = 9), normal females (n = 3) and haemophilia A carrier females (n = 2). All women with affected haemophilia sons requested to terminate their pregnancies except one woman. One of 32 pregnancies (3.1%) had spontaneous abortion. At follow-up after birth, the PND was accurately confirmed in one haemophilia A male, three normal females and two carrier females by laboratory testing, and 18 unaffected normal males by history taking of no bleeding manifestations. However, 10 women who continued their pregnancies after knowing foetal sex turned out to have two haemophilia A males, one normal female, one haemophilia A carrier female and six normal or carrier females.

CONCLUSION

The PND of haemophilia could be accurately determined but it was not well accepted by all couples at risk.