"Fertility and Pregnancy in Cystic fibrosis"

Maternal and fetal outcomes in multiparous women with Cystic Fibrosis

BACKGROUND

Quality of life and survival in Cystic Fibrosis (CF) have improved dramatically, making family planning a feasible option. Maternal and perinatal outcomes in women with CF (wwCF) are similar to those seen in the general population. However, the effect of undergoing multiple pregnancies is unknown.

METHODS

A multinational-multicenter retrospective cohort study. Data was obtained from 18 centers worldwide, anonymously, on wwCF 18-45 years old, including disease severity and outcome, as well as obstetric and newborn complications. Data were analyzed, within each individual patient to compare the outcomes of an initial pregnancy (1st or 2nd) with a multigravid pregnancy (≥3) as well as secondary analysis of grouped data to identify risk factors for disease progression or adverse neonatal outcomes. Three time periods were assessed - before, during, and after pregnancy.

RESULTS

The study population included 141 wwCF of whom 41 (29%) had ≥3 pregnancies, "multiparous". Data were collected on 246 pregnancies, between 1973 and 2020, 69 (28%) were multiparous. A greater decline in ppFEV1 was seen in multiparous women, primarily in pancreatic insufficient (PI) wwCF and those with two severe (class I-III) mutations. Multigravid pregnancies were shorter, especially in wwCF over 30 years old, who had high rates of prematurity and newborn complications. There was no effect on pulmonary exacerbations or disease-related complications.

CONCLUSIONS

Multiple pregnancies in wwCF are associated with accelerated respiratory deterioration and higher rates of preterm births. Therefore, strict follow-up by a multidisciplinary CF and obstetric team is needed in women who desire to carry multiple pregnancies.

[Cystic fibrosis in childhood and adulthood]

BACKGROUND

Cystic fibrosis (CF, or mucoviscidosis) is one of the rare diseases with a fatal course and with the highest prevalence. Formerly known as a purely childhood disease, this multisystemic disease follows an autosomal recessive inheritance pattern and results in a malfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, leading to the production of viscous secretions. The prognosis and outcome of CF are determined by the severity of the involvement of the lungs. Other typically affected organs include the pancreas, liver and intestines.

OBJECTIVE

This article reviews the clinical presentation and evolution of CF with a focus on the new era of the highly effective CFTR modulator treatment.

MATERIAL AND METHODS

An overview of the current state of knowledge on the care for CF patients is presented.

RESULTS AND DISCUSSION

The introduction of the CF newborn screening, the increased understanding of the disease and the development of novel treatment options have substantially increased the quality of life and life expectancy of people with CF. As a result, more than half of CF patients in Germany are now older than 18 years of age and the complications of a chronic disease as well as organ damage due to the intensive treatment are gaining in importance. The highly effective CFTR modulator treatment results in a significant improvement in CFTR function, lung function, body mass index and quality of life and is available to approximately 90% of patients in Germany, based on the genotype. Nevertheless, further research including the development of causal treatment, e.g., gene therapy, targeting the underlying defect in the remaining 10% of CF patients, is urgently needed. Even in adult patients, CF with a mild course or a CFTR-related disease should be considered, e.g., in cases of bronchiectasis and/or recurrent abdominal complaints.

Genome-wide analyses identify 21 infertility loci and over 400 reproductive hormone loci across the allele frequency spectrum

Genome-wide association studies (GWASs) may help inform treatments for infertility, whose causes remain unknown in many cases. Here we present GWAS meta-analyses across six cohorts for male and female infertility in up to 41,200 cases and 687,005 controls. We identified 21 genetic risk loci for infertility (P≤5E-08), of which 12 have not been reported for any reproductive condition. We found positive genetic correlations between endometriosis and all-cause female infertility (rg=0.585, P=8.98E-14), and between polycystic ovary syndrome and anovulatory infertility (rg=0.403, P=2.16E-03). The evolutionary persistence of female infertility-risk alleles in EBAG9 may be explained by recent directional selection. We additionally identified up to 269 genetic loci associated with follicle-stimulating hormone (FSH), luteinising hormone, oestradiol, and testosterone through sex-specific GWAS meta-analyses (N=6,095-246,862). While hormone-associated variants near FSHB and ARL14EP colocalised with signals for anovulatory infertility, we found no rg between female infertility and reproductive hormones (P>0.05). Exome sequencing analyses in the UK Biobank (N=197,340) revealed that women carrying testosterone-lowering rare variants in GPC2 were at higher risk of infertility (OR=2.63, P=1.25E-03). Taken together, our results suggest that while individual genes associated with hormone regulation may be relevant for fertility, there is limited genetic evidence for correlation between reproductive hormones and infertility at the population level. We provide the first comprehensive view of the genetic architecture of infertility across multiple diagnostic criteria in men and women, and characterise its relationship to other health conditions.

Potential systemic effects of acquired CFTR dysfunction in COPD

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, respiratory symptoms, inflammation of the airways, and systemic manifestations of the disease. Genetic susceptibility and environmental factors are important in the development of the disease, particularly exposure to cigarette smoke which is the most notable risk factor. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are the cause of cystic fibrosis (CF), which shares several pathophysiological pulmonary features with COPD, including airway obstruction, chronic airway inflammation and bacterial colonization; in addition, both diseases also present systemic defects leading to comorbidities such as pancreatic, gastrointestinal, and bone-related diseases. In patients with COPD, systemic CFTR dysfunction can be acquired by cigarette smoking, inflammation, and infection. This dysfunction is, on average, about half of that found in CF. Herein we review the literature focusing on acquired CFTR dysfunction and the potential role in the pathogenesis of comorbidities associated with COPD and chronic bronchitis.

The role of CFTR channel in female infertility

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated trans-membrane ATP gated anion channel present in most epithelia, which transports chloride and bicarbonate ions across the apical membrane. Mutations in the CFTR protein are known to result in defective expression or function, notably the inhibition of chloride and bicarbonate transport. This can result in cystic fibrosis (CF), a disorder characterised by thickness of the mucus lining of the epithelial cells of the alimentary and respiratory tracts, sweat ducts and reproductive organs. As a consequence, there is a reduction in fluid transport at the apical surface. While the most devastating effect of CF is mortality, about 98% of men with CF are infertile, consequent of early blockage of or failure to develop the mesonephrotic ducts as well as the vas deferens. The effect of CF of female fertility is less well-understood. This review highlights the genetics and pathophysiology as well as the mechanism of action of CF on female infertility.

The modern landscape of fertility, pregnancy, and parenthood in people with cystic fibrosis

PURPOSE OF REVIEW

With improved long-term survival and the expanding availability of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapies that treat the underlying genetic defect in cystic fibrosis, more people are interested in parenthood. Cystic fibrosis care centers and people with cystic fibrosis need more information to guide decisions related to parenting.

RECENT FINDINGS

Here we present currently available data on fertility, pregnancy, and parenthood in the modern era of cystic fibrosis care. Fertility may be improving in female individuals with cystic fibrosis with the use of CFTR modulator therapies, and there is an associated increase in annual pregnancies. Infertility in male individuals with cystic fibrosis remains approximately 97-98% and is unchanged with CFTR modulators in those already born with cystic fibrosis. As more female individuals with cystic fibrosis experience pregnancy, questions remain about the impact of pregnancy on their health and that of their child. Fortunately, there are multiple routes to becoming a parent; however, more work is needed to understand the impact of pregnancy and parenthood in the context of CF as some previous data suggests potential challenges to the health of parents with cystic fibrosis.

SUMMARY

We encourage cystic fibrosis care teams to have knowledge and resources available to support the reproductive goals of all individuals with cystic fibrosis.

Unplanned pregnancies following the introduction of elexacaftor/tezacaftor/ivacaftor therapy in women with cystic fibrosis

Cystic fibrosis (CF) causes infertility and subfertility due to various factors, including altered cervical mucus, delayed puberty, and hormonal imbalances. With the introduction of the CFTR modulator therapy elexacaftor-tezacaftor-ivacaftor, we have observed an increase in unplanned pregnancies among women undergoing ETI treatment in our CF center, despite repeated recommendations for strict fertility monitoring. It appears that these pregnancies are more likely attributed to reduced attention to the possibility of conception rather than contraceptive failure. The perception of subfertility developed by women with CF over time, before the era of modulators, can influence their long-term habits and lead to the underuse of contraceptive methods. While further research is needed to fully understand the effects of ETI on fertility, healthcare providers should be attentive to the fertility concerns of women with CF, particularly those treated with modulators in adulthood.

Understanding and addressing the needs of people with cystic fibrosis in the era of CFTR modulator therapy

Cystic fibrosis is a multiorgan disease caused by impaired function of the cystic fibrosis transmembrane conductance regulator (CFTR). Since the introduction of the CFTR modulator combination elexacaftor-tezacaftor-ivacaftor (ETI), which acts directly on mutant CFTR to enhance its activity, most people with cystic fibrosis (pwCF) have seen pronounced reductions in symptoms, and studies project marked increases in life expectancy for pwCF who are eligible for ETI. However, modulator therapy has not cured cystic fibrosis and the success of CFTR modulators has resulted in immediate questions about the new state of cystic fibrosis disease and clinical challenges in the care of pwCF. In this Series paper, we summarise key questions about cystic fibrosis disease in the era of modulator therapy, highlighting state-of-the-art research and clinical practices, knowledge gaps, new challenges faced by pwCF and the potential for future health-care challenges, and the pressing need for additional therapies to treat the underlying genetic or molecular causes of cystic fibrosis.

Association between unplanned pregnancies and maternal exacerbations in cystic fibrosis

INTRODUCTION

Following availability of the highly effective cystic fibrosis (CF) transmembrane conductance regulator modulator, elexacaftor/tezacaftor/ivacaftor, there was a near doubling of pregnancies reported in the United States (US) in people with CF. We sought to determine health impacts of planned (PP) versus unplanned pregnancies (UP).

METHODS

We collected retrospective pregnancy data from January 2010-December 2020 from 11 US CF centers. After adjusting for potential confounding effects, we conducted multivariable, multilevel longitudinal regression analysis using mixed effect modeling to assess whether changes in percent predicted forced expiratory volume in one second (ppFEV1), body mass index (BMI), and pulmonary exacerbations (PEx) 1-year-pre- to 1-year-post-pregnancy were associated with pregnancy planning.

RESULTS

Our analysis included 163 people with 226 pregnancies; the cohort had a mean age at conception of 29.6 years, mean pre-pregnancy ppFEV1 of 75.4 and BMI of 22.5 kg/m2. PpFEV1 declined in both PP (adjusted decline of -2.5 (95% CI: -3.8, -1.2)) and UP (adjusted decline of -3.0 (95% CI: -4.6, -1.4)) groups, they did not differ from each other (p = 0.625). We observed a difference in change in the annual number of PEx pre- to post-pregnancy (PP: 0.8 (0.7, 1.1); UP: 1.3 (1.0, 1.7); interaction effect p = 0.029). In a subset of people with available infant data, infants resulting from UP had more preterm births, lower APGAR scores, and more intensive care unit stays.

CONCLUSIONS

Following UP, there is an increased trajectory for PEx and potentially for infant complications compared to PP. Clinicians should consider increased surveillance in the setting of UP.

Sexual and Reproductive Health Among Men With Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Due to the distribution of the CFTR protein, CF presents with a heterogeneous phenotype. Men with CF may present with infertility due to congenital abnormalities of the vas deferens. In addition, they may experience testosterone deficiency. Today, they can father biological children with assisted reproductive technologies. We reviewed the current literature on the pathophysiology of these conditions, describe interventions that allow men with CF to conceive biological children, and provide recommendations for management of CF patients with reproductive health concerns.

Cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by variants in the gene encoding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CFTR dysfunction results in abnormal chloride and bicarbonate transport in epithelial cells, leading to a multiorgan disease dominated by respiratory and digestive manifestations. The respiratory disease, which is characterized by airway mucus plugging, chronic bacterial infection and progressive development of bronchiectasis, may lead to chronic respiratory failure, which is the main cause of premature death in people with CF. Over the past 50 years, major progress has been obtained by implementing multidisciplinary care, including nutritional support, airway clearance techniques and antibiotics in specialized CF centers. The past 10 years have further seen the progressive development of oral medications, called CFTR modulators, that partially restore ion transport and lead to a major improvement in clinical manifestations and lung function, presumably resulting in longer survival. Although an increasing proportion of people with CF are being treated with CFTR modulators, challenges remain regarding access to CFTR modulators due to their high cost, and their lack of marketing approval and/or effectiveness in people with rare CFTR variants. The anticipated increase in the number of adults with CF and their aging also challenge the current organization of CF care. The purpose of this review article is to describe current status and future perspective of CF disease and care.

Ovarian reserve in women with cystic fibrosis: is this a cause of sub-fertility?

BACKGROUND

Over the past two decades, increasing number of people with cystic fibrosis (CF) survive into adulthood. Compared to the general population, sub-fertility is an obstacle for many women with CF (wwCF). Decreased ovarian reserve has been proposed as a possible cause, but limited data is available to support this. The aim of this study was to evaluate the ovarian reserve in wwCF and to correlate this with patients' demographic and clinical data.

METHODS

Reproductive-aged wwCF were enrolled during their routine medical appointments. Assessment included Anti-Mullerian hormone (AMH) levels, routine blood tests and antral follicular count (AFC) evaluation. Additionally, demographic, and clinical information were collected.

RESULTS

A total of wenty-three wwCF were enrolled, with ages ranging from 19 to 40 years (median 27 years). Among the fourteen wwCF who were considering pregnancy, five (35.7%) disclosed undergoing an infertility assessment and receiving fertility treatments. All but one patient had an Anti-Mullerian hormone (AMH) level between the 5th and 95th % for age. Measurement of the antral follicular count (AFC) was possible in 12 of the 23 patients and was ranging 8-40 with a median of 17. The proportion of wwCF presenting below median AMH values was not different in sub-fertile as compared to fertile wwCF (P value 0.54). There were no correlations between AMH levels and disease severity parameters. AMH seemed to be relatively higher in wwCF with mild class mutations, but this was not shown to have statistical significance.

CONCLUSIONS

Our results, in contrast with the limited available published data, do not support the hypothesis that decreased ovarian reserve plays a major role in infertility in wwCF.

Role of innate immunity and systemic inflammation in cystic fibrosis disease progression

Pathophysiological manifestations of cystic fibrosis (CF) result from a functional defect in the cystic fibrosis transmembrane conductance regulator (CFTR) paving way for mucus obstruction and pathogen colonization. The role of CFTR in modulating immune cell function and vascular integrity, irrespective of mucus thickening, in determining the host cell response to pathogens/allergens and causing systemic inflammation is least appreciated. Since CFTR plays a key role in the conductance of anions like Cl^-, loss of CFTR function could affect various basic cellular processes, such as cellular homeostasis, lysosome acidification, and redox balance. CFTR aids in endotoxin tolerance by regulating Toll-like receptor-mediated signaling resulting in uncontrolled activation of innate immune cells. Although leukocytes of CF patients are hyperactivated, they exhibit compromised phagosome activity thus favouring the orchestration of sepsis from defective pathogen clearance. This review will emphasize the importance of innate immunity and systemic inflammatory response in the development of CF and other CFTR-associated pathologies.

A FOETUS WITH CYSTIC FIBROSIS – TO TREAT OR NOT TO TREAT?

BACKGROUND

Cystic fibrosis (CF) is an autosomal recessive health condition caused by gene mutations causing quantitative and or qualitative defect in the cystic-fibrosis transmembrane conductance regulator (CFTR) protein. CFTR defects lead to abnormal ion transport affecting multiple body systems. In CF thick secretions accumulate causing impairment in the pancreas, whole airways, gut and reproductive organs.

CFTR MODULATORS AND PREGNANCY

CFTR modulators have improved the quantity and quality of life of CF patients. There is limited literature on CFTR modulator use in pregnancy and its impact on foetal health. A recent case report described a child with CF being born with pancreatic sufficiency following in-utero CFTR modulator exposure. We review the potential impact of in-utero exposure to CFTR modulators, focusing on pancreatic function and future fertility of unborn individuals with CF.

CONCLUSION

CFTR modulator exposure in-utero is a new concept, therefore the consequences on foetal health remain uncertain. Foetal exposure to modulators could prevent pancreatic damage and infertility.

The Impact of Highly Effective Cystic Fibrosis Transmembrane Conductance Regulator Modulators on the Health of Female Subjects With CF

Cystic fibrosis (CF) is a genetic disorder that occurs in people of all genetic ancestries. CF is caused by variants in the CF transmembrane conductance regulator (CFTR) gene that result in decreased, absent, or nonfunctional CFTR protein at the cell surface of the mucous membranes. Clinical manifestations include chronic respiratory disease, malabsorption, and decreased fertility. Historically, therapies for CF were focused on the signs and symptoms of the disease. However, more recently, CFTR modulators, therapies directed at the basic defect, are improving the quality and duration of the lives of people with CF. The predicted survival of people with CF in the United States is now 53 years of age. With the hope of longer, healthier lives, female individuals with CF (fwCF) are expressing the desire to discuss fertility, pregnancy, and parenthood. Furthermore, pregnancy rates are increasing substantially. Understanding the impact of use or discontinuation of highly effective modulator therapy on the reproductive health of fwCF is critical. Finally, fwCF and their providers must consider preventative cancer screening. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

Pregnancy in Cystic Fibrosis-Past, Present, and Future

The introduction of mutation-specific therapy led to a revolution in cystic fibrosis (CF) care. These advances in CF therapies have changed the disease profile from a severe incurable disease with limited survival to a treatable disease with improved quality of life and survival into adulthood. CF patients are now able to plan their future, including marriage and parenthood. Side by side with the optimism, new issues and concerns are arising, including fertility and preparation for pregnancy, maternal and fetal care during pregnancy, and post-partum care. While cystic fibrosis transmembrane regulator (CFTR) modulators show promising results for improving CF lung disease, data on their safety in pregnancy are still limited. We performed a literature review on pregnancy in CF from the past, with the first described pregnancy in 1960, through the current fascinating changes in the era of CFTR modulators, to ongoing studies and future directions. Current advances in knowledge give hope for improved outcomes of pregnancy, towards the best possible prognosis for the mother and for the baby.

Sex and Gender in Lung Diseases and Sleep Disorders: A State-of-the-Art Review: Part 2

There is now ample evidence that differences in sex and gender contribute to the incidence, susceptibility, presentation, diagnosis, and clinical course of many lung diseases. Some conditions are more prevalent in women, such as pulmonary arterial hypertension and sarcoidosis. Some life stages-such as pregnancy-are unique to women and can affect the onset and course of lung disease. Clinical presentation may differ as well, such as the higher number of exacerbations experienced by women with cystic fibrosis (CF), more fatigue in women with sarcoidosis, and more difficulty in achieving smoking cessation. Outcomes such as mortality may be different as well, as indicated by the higher mortality in women with CF. In addition, response to therapy and medication safety may also differ by sex, and yet, pharmacogenomic factors are often not adequately addressed in clinical trials. Various aspects of lung/sleep biology and pathobiology are impacted by female sex and female reproductive transitions. Differential gene expression or organ development can be impacted by these biological differences. Understanding these differences is the first step in moving toward precision medicine for all patients. This article is the second part of a state-of-the-art review of specific effects of sex and gender focused on epidemiology, disease presentation, risk factors, and management of selected lung diseases. We review the more recent literature and focus on guidelines incorporating sex and gender differences in pulmonary hypertension, CF and non-CF bronchiectasis, sarcoidosis, restless legs syndrome and insomnia, and critical illness. We also provide a summary of the effects of pregnancy on lung diseases and discuss the impact of sex and gender on tobacco use and treatment of nicotine use disorder.

Clinical features of the course of cystic fibrosis during pregnancy and childbirth

Cystic fibrosis is one of the urgent medical and social problems of health care systems in most countries due to fairly high prevalence, development of multi-organ lesions, and poor outcomes.

Due to modern advances in the diagnosis and treatment of cystic fibrosis, not only has the average life expectancy of patients increased, but their quality of life has also improved, and it has become possible to maintain pregnancy and childbearing. Since cystic fibrosis can adversely affect the course of pregnancy, childbirth, and health of both mother and child, proper management of women with cystic fibrosis during pregnancy and childbirth is of particular relevance. The presented clinical case is an example of competent supervision at all stages of monitoring of a patient with cystic fibrosis during pregnancy and childbirth.

Standards of care for CFTR variant-specific therapy (including modulators) for people with cystic fibrosis

Cystic fibrosis (CF) has entered the era of variant-specific therapy, tailored to the genetic variants in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. CFTR modulators, the first variant-specific therapy available, have transformed the management of CF. The latest standards of care from the European CF Society (2018) did not include guidance on variant-specific therapy, as CFTR modulators were becoming established as a novel therapy. We have produced interim standards to guide healthcare professionals in the provision of variant-specific therapy for people with CF. Here we provide evidence-based guidance covering the spectrum of care, established using evidence from systematic reviews and expert opinion. Statements were reviewed by key stakeholders using Delphi methodology, with agreement (≥80%) achieved for all statements after one round of consultation. Issues around accessibility are discussed and there is clear consensus that all eligible people with CF should have access to variant-specific therapy.

Serum kisspeptin and proopiomelanocortin in cystic fibrosis: a single study

The determination of hormonal biomarkers is of increasing interest in many diseases, including cystic fibrosis (CF). Hormones that have not been estimated and described so far in CF include kisspeptin (KISS) and proopiomelanocortin (POMC), which are involved in the regulation of many processes, including appetite and fertility. Therefore, the aim of our study was to estimate the level of KISS and POMC in sera from CF patients and to determine the correlation between these hormones and clinical parameters. For this purpose, we estimated the levels of KISS and POMC in 38 CF patients and 16 healthy participants with enzyme-linked immunosorbent assay. We found significantly reduced levels of KISS and POMC in people with CF compared to healthy subjects (1.76 ± 0.46 vs. 2.27 ± 0.56 ng/mL, p < 0.05 and 6.25 ± 4.36 vs. 14.74 ± 6.24 ng/mL, p < 0.001, respectively). Furthermore, the level of both hormones was negatively correlated with age. The hormones studied did not correlate with the results of spirometry and each other. Thus, decreased KISS and POMC levels may be associated with lower body weight and delayed puberty in patients with CF.

Pregnancy experience in the setting of cystic fibrosis: A systematic review and thematic synthesis

AIMS

To synthesize qualitative studies of subjective experience of pregnancy in people with cystic fibrosis.

DESIGN

Thematic synthesis of qualitative studies.

DATA SOURCES

We searched PUBMED, CINAHL, EMBASE. PsicINFO and Social Sciences Citation Index for qualitative studies published in English, which reported on pregnancy in people with cystic fibrosis. Searches were carried out in March 2021, updated in June 2022.

REVIEW METHODS

Studies that met the inclusion criteria were appraised for quality using the Critical Appraisal Skills Programme (CASP) for qualitative research. Data were extracted from the studies, analyse and synthesise using thematic synthesis approach.

RESULTS

Thirteen studies were included in the review and 'Walking on a wire' framework was conceptualized. We found three analytical themes: (1) desire for information related to pregnancy in cystic fibrosis, (2) factors at play in decision-making related to pregnancy for people with cystic fibrosis and (3) pregnancy experience and eight descriptive themes: (1) information topics, (2) CF healthcare team/PwCF as a provider of reproductive health information, (3) information timing, (4) barriers to information delivery, (5) barriers to decision-making and stresses relating to the process of trying to conceive, (6) environmental factors, (7) coping with challenges, and (8) moving towards parenthood.

CONCLUSION

For people with cystic fibrosis, pregnancy is a complex pathway: the amount of knowledge about cystic fibrosis and sexual and reproductive health, barriers to pregnancy and environmental factors provides the background to decision-making. Moreover, coping with pregnancy is a challenging experience, where they have to mediate between the physical and emotional implications of planning a pregnancy and the limitations imposed by the chronic health conditions.

IMPACT

Understanding the psychological experiences of people with cystic fibrosis (PwCF) will improve future research and practice. Education about sexual and reproductive health and psychosocial care programmes are necessary to help PwCF deal with the challenges related to pregnancy. Hospitals should enhance the development of specific programmes to promote the well-being of individuals with CF who are planning a pregnancy.

Identification and selection of healthy spermatozoa in heterozygous carriers of the Phe508del-variant of the CFTR-gene in assisted reproduction

The pathogenic variant Phe508del of the CFTR-gene is the most frequent cause of cystic fibrosis (CF). Whereas male CF-patients are infertile due to bilateral agenesis of the efferent ducts, the fertility status of male heterozygous carriers is uncertain. We aimed at demonstrating the involvement of the CFTR-ion channel during sperm capacitation and to potentially select variant-free spermatozoa in heterozygous carriers of the CFTR-variant using flow cytometry (FC). Using FC and sorting, single cell polymerase chain reaction, immuno-fluorescent staining an experimental study was performed on nine fertile semen donors and three heterozygous infertile men carrying the Phe508del gene variant. Chemical inhibition of CFTR interfered with sperm capacitation. Most viable spermatozoa of heterozygous carriers of the Phe508del variant of the CFTR-gene show immune-fluorescent CFTR. Sperm capacitation in Phe508del carriers was similar to that in healthy semen donors. Distribution of the Phe508del allele in trio data of CF-affected families corresponded to the expected recessive inheritance pattern. Infertility in Phe508del heterozygous men is unlikely to be caused by the pathogenic variant although some contribution cannot be excluded. Normal sperm capacitation in carriers of pathogenic variants of the Phe508del-gene may in part explain the high prevalence of a potentially lethal recessive disorder.