Association Between Fertility Treatment and Cancer Risk in Children

Reproductive outcomes in fresh transfer cycles and antagonists with premature luteinizing and/or progesterone surge: a single center retrospective cohort study

Background

The optimal outcome of assisted reproductive technology is a successful live birth after fresh embryo transfer. However, the success pregnancy rate of fresh embryo transfer cycle in antagonist protocol is lower than that observed in other protocols. Despite the use of antagonists (GnRH-ant), the incidence of luteinizing hormone surge and elevated progesterone levels remain at approximately 5%-38%. Progesterone is widely recognized to exert adverse effects on fresh embryo transfer outcomes. This study aimed to investigate the impact of luteinizing hormone surge and progesterone levels on live birth rate following fresh embryo transfer and explore appropriate progesterone thresholds to enhance pregnancy outcomes.

Methods

This retrospective cohort study included a total of 1,177 antagonist protocol cycles with fresh embryo transfer. The patients were divided into four groups based on the presence of premature LH surge and progesterone level on trigger day>1.5ng/ml. Then, the relationship between the variables and the pregnancy outcome was analyzed and compared in each group.

Results

The transient rise of luteinizing hormone did not impact pregnancy outcomes (P=0.345; P=0.3; P=0.787), in contrast to progesterone levels on the day of hCG administration (P=0.047*; P=0.015*; P=0.021*). In cases with luteinizing hormone surge, elevated progesterone levels were correlated with higher antral follicle count (AFC), and as progesterone levels increased, a greater quantity of oocytes and embryos were obtained. However, there was no statistically significant difference in pregnancy outcomes. In cases without luteinizing hormone surge, elevated progesterone levels led to significantly poorer pregnancy outcomes. Furthermore, the curve-fitting and threshold-effect analysis revealed a notable decline in live birth rates when progesterone exceeded or equaled 1.10ng/ml (OR, 0.25; 95% CI, 0.09-0.66; P = 0.005*).

Conclusion

The GnRH-ant dosage addition should be carefully selected in flexible antagonist protocols. The presence of elevated progesterone levels may be associated with improved embryo quality when luteinizing hormone surge occurred. In the absence of a luteinizing hormone surge, progesterone levels showed a larger impact on the pregnancy outcome, and fresh embryo transfer should not be performed if the progesterone level on the day of hCG administration is higher than 1.10ng/ml.

Safety of embryo cryopreservation: insights from mid-term placental transcriptional changes

BACKGROUND

In recent years, with benefits from the continuous improvement of clinical technology and the advantage of fertility preservation, the application of embryo cryopreservation has been growing rapidly worldwide. However, amidst this growth, concerns about its safety persist. Numerous studies have highlighted the elevated risk of perinatal complications linked to frozen embryo transfer (FET), such as large for gestational age (LGA) and hypertensive disorders during pregnancy. Thus, it is imperative to explore the potential risk of embryo cryopreservation and its related mechanisms.

METHODS

Given the strict ethical constraints on clinical samples, we employed mouse models in this study. Three experimental groups were established: the naturally conceived (NC) group, the fresh embryo transfer (Fresh-ET) group, and the FET group. Blastocyst formation rates and implantation rates were calculated post-embryo cryopreservation. The impact of FET on fetal growth was evaluated upon fetal and placental weight. Placental RNA-seq was conducted, encompassing comprehensive analyses of various comparisons (Fresh-ET vs. NC, FET vs. NC, and FET vs. Fresh-ET).

RESULTS

Reduced rates of blastocyst formation and implantation were observed post-embryo cryopreservation. Fresh-ET resulted in a significant decrease in fetal weight compared to NC group, whereas FET reversed this decline. RNA-seq analysis indicated that the majority of the expression changes in FET were inherited from Fresh-ET, and alterations solely attributed to embryo cryopreservation were moderate. Unexpectedly, certain genes that showed alterations in Fresh-ET tended to be restored in FET. Further analysis suggested that this regression may underlie the improvement of fetal growth restriction in FET. The expression of imprinted genes was disrupted in both FET and Fresh-ET groups.

CONCLUSION

Based on our experimental data on mouse models, the impact of embryo cryopreservation is less pronounced than other in vitro manipulations in Fresh-ET. However, the impairment of the embryonic developmental potential and the gene alterations in placenta still suggested it to be a risky operation.

Association between frozen embryo transfer and childhood allergy: a retrospective cohort study

RESEARCH QUESTION

Does frozen embryo transfer (FET) increase the risk of allergic diseases in offspring?

DESIGN

This study followed up 653 singleton children: 166 born through FET and 487 born through natural conception. Demographic characteristics, perinatal information and allergic diseases of children and their parents were collected through clinical medical systems and questionnaires. Among these 653 children, allergen-specific immunoglobulin E (IgE) testing was performed using peripheral blood samples collected from 207 children: 145 in the FET group and 62 in the natural conception group. The prevalence of allergic diseases and positive rates of allergen-specific IgE testing were compared between the two groups with adjustments for confounding factors.

RESULTS

The prevalence of food allergy was significantly higher in children born through FET compared with children born through natural conception (adjusted OR = 3.154, 95% CI 1.895-5.250; P < 0.001). In addition, positive rates of food allergen sensitization were higher in children in the FET group compared with children in the natural conception group (adjusted OR = 5.769, 95% CI 2.859-11.751, P < 0.001). Children in the FET group had a higher positive sensitization rate to at least one allergen compared with children in the natural conception group (adjusted OR = 3.127, 95% CI 1.640-5.961, P < 0.001). No association was observed between FET and other allergic diseases, including asthma (P = 0.136), atopic dermatitis (P = 0.130) and allergic rhinitis (P = 0.922). Allergen sensitization IgE testing indicated no differences between the two groups in terms of positive sensitization rates of other common allergens, including animal and insect allergens (P = 0.627), inhaled outdoor allergens (P = 0.915) and inhaled outdoor allergens (P = 0.544).

CONCLUSION

This study suggests that children born through FET have increased risk of developing food allergy in early childhood.

Medically Assisted Reproduction and Risk of Cancer Among Offspring

Importance

Cancer is a leading cause of death among children worldwide. Treatments used for medically assisted reproduction (MAR) are suspected risk factors because of their potential for epigenetic disturbance and associated congenital malformations.

Objective

To assess the risk of cancer, overall and by cancer type, among children born after MAR compared with children conceived naturally.

Design, Setting, and Participants

For this cohort study, the French National Mother-Child Register (EPI-MERES) was searched for all live births that occurred in France between January 1, 2010, and December 31, 2021 (and followed up until June 30, 2022). The EPI-MERES was built from comprehensive data of the French National Health Data System. Data analysis was performed from December 1, 2021, to June 30, 2023.

Exposure

Use of assisted reproduction technologies (ART), such as fresh embryo transfer (ET) or frozen ET (FET), and artificial insemination (AI).

Main Outcomes and Measures

The risk of cancer was compared, overall and by cancer type, among children born after fresh ET, FET, or AI and children conceived naturally, using Cox proportional hazards regression models adjusted for maternal and child characteristics at birth.

Results

This study included 8 526 306 children with a mean (SD) age of 6.4 (3.4) years; 51.2% were boys, 96.4% were singletons, 12.1% were small for gestational age at birth, and 3.1% had a congenital malformation. There were 260 236 children (3.1%) born after MAR, including 133 965 (1.6%) after fresh ET, 66 165 (0.8%) after FET, and 60 106 (0.7%) after AI. A total of 9256 case patients with cancer were identified over a median follow-up of 6.7 (IQR, 3.7-9.6) years; 165, 57, and 70 were born after fresh ET, FET, and AI, respectively. The overall risk of cancer did not differ between children conceived naturally and those born after fresh ET (hazard ratio [HR], 1.12 [95% CI, 0.96 to 1.31]), FET (HR, 1.02 [95% CI, 0.78 to 1.32]), or AI (HR, 1.09 [95% CI, 0.86 to 1.38]). However, the risk of acute lymphoblastic leukemia was higher among children born after FET (20 case patients; HR 1.61 [95% CI, 1.04 to 2.50]; risk difference [RD], 23.2 [95% CI, 1.5 to 57.0] per million person-years) compared with children conceived naturally. Moreover, among children born between 2010 and 2015, the risk of leukemia was higher among children born after fresh ET (45 case patients; HR, 1.42 [95% CI, 1.06 to 1.92]; adjusted RD, 19.7 [95% CI, 2.8 to 43.2] per million person-years).

Conclusions and Relevance

The findings of this cohort study suggest that children born after FET or fresh ET had an increased risk of leukemia compared with children conceived naturally. This risk, although resulting in a limited number of cases, needs to be monitored in view of the continuous increase in the use of ART.

Assisted Reproductive Technologies: A New Player in the Foetal Programming of Childhood and Adult Diseases?

Assisted reproductive technology (ART) is an emerging field in medicine that incorporates complex procedures and has profound ethical, moral, social, religious, and economic implications not just for the individuals who have access to this method but also for society. In this narrative review, we summarise multiple aspects of ART procedures and the possible consequences on the mother and newborn. Moreover, we provide an overview of the possible long-term consequences of ART procedures on the health of newborns, although longitudinal evidence is particularly scant. Users should be informed that ART procedures are not risk-free to prepare them for the possible negative outcomes that may occur in the perinatal period or even in childhood and adulthood. Indeed, risk estimates point to increased liability for major nonchromosomal birth defects; cardiovascular, musculoskeletal, and urogenital (in male newborns) defects; and any other birth defects. Less certainty is present for the risk of neuropsychiatric sequelae in children conceived through ART. Thus, its application should be accompanied by adequate counselling and psychological support, possibly integrated into specific multidisciplinary clinical programmes.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

Frequency, morbidity and equity - the case for increased research on male fertility

Currently, most men with infertility cannot be given an aetiology, which reflects a lack of knowledge around gamete production and how it is affected by genetics and the environment. A failure to recognize the burden of male infertility and its potential as a biomarker for systemic illness exists. The absence of such knowledge results in patients generally being treated as a uniform group, for whom the strategy is to bypass the causality using medically assisted reproduction (MAR) techniques. In doing so, opportunities to prevent co-morbidity are missed and the burden of MAR is shifted to the woman. To advance understanding of men's reproductive health, longitudinal and multi-national centres for data and sample collection are essential. Such programmes must enable an integrated view of the consequences of genetics, epigenetics and environmental factors on fertility and offspring health. Definition and possible amelioration of the consequences of MAR for conceived children are needed. Inherent in this statement is the necessity to promote fertility restoration and/or use the least invasive MAR strategy available. To achieve this aim, protocols must be rigorously tested and the move towards personalized medicine encouraged. Equally, education of the public, governments and clinicians on the frequency and consequences of infertility is needed. Health options, including male contraceptives, must be expanded, and the opportunities encompassed in such investment understood. The pressing questions related to male reproductive health, spanning the spectrum of andrology are identified in the Expert Recommendation.

The adverse effects of vitrification on mouse embryo development and metabolic phenotype in offspring

Embryo vitrification is a standard procedure in assisted reproductive technology. Previous studies have shown that frozen embryo transfer is associated with an elevated risk of adverse maternal and neonatal outcomes. This study aimed to explore the effects of mouse blastocyst vitrification on the phenotype of vitrified-warmed blastocysts, their intrauterine and postnatal development, and the long-term metabolic health of the derived offspring. The vitrified-warmed blastocysts (IVF + VT group) exhibited reduced mitochondrial activity, increased apoptotic levels, and decreased cell numbers when compared to the fresh blastocysts (IVF group). Implantation rates, live pup rates, and crown-rump length at E18.5 were not different between the two groups. However, there was a significant decrease in fetal weight and fetal/placental weight ratio in the IVF + VT group. Furthermore, the offspring of the IVF + VT group at an age of 36 weeks had reduced whole energy consumption, impaired glucose and lipid metabolism when compared with the IVF group. Notably, RNA-seq results unveiled disturbed hepatic gene expression in the offspring from vitrified-warmed blastocysts. This study revealed the short-term negative impacts of vitrification on embryo and fetal development and the long-term influence on glucose and lipid metabolism that persist from the prenatal stage into adulthood in mice.

Planned Oocyte Cryopreservation: A Review of Current Evidence on Outcomes, Safety and Risks

Although oocyte cryopreservation was initially used as a fertility preservation strategy for medical indications, it is now is increasingly used to circumvent age-related infertility. Outcomes following planned oocyte vitrification, also known as elective egg freezing, are limited. Current studies show higher success rates for individuals undergoing fertility preservation treatment under age 35. Additionally, while freezing 20 oocytes is optimal to achieve pregnancy, freezing at least 8-10 oocytes is recommended. While fertility is not guaranteed, current evidence demonstrates that planned oocyte vitrification is an overall safe, low risk method of fertility preservation to reduce the risk for age-related infertility.

Polygenic embryo screening: are there potential maternal and fetal harms?

Polygenic embryo screening (PES) and its derivate the Embryo Health Score (EHS) have generated interest in both infertile and fertile populations due to their potential ability to select embryos with a reduced risk of disease and improved long-term health outcomes. Concerns have been raised regarding the potential harms of IVF itself, including possible epigenetic changes that may affect the health of the offspring in late adulthood, which are not fully captured in the EHS calculation. Knowledge of the potential impacts of the trophectoderm biopsy, which is a key component of the PES procedure, on the offsprings' health is limited by the heterogeneity of the population characteristics used in the published studies. Nonetheless, the literature suggests a possible increased risk of preterm delivery, birth defects and pre-eclampsia after trophectoderm biopsy. Overall, the risks of PES for prenatal and postnatal health remain uncertain, and further research is needed. Counselling patients regarding these risks before considering PES is important, to provide an understanding of the risks and benefits. This review aims to highlight some of these issues, the need for continued investigation in this area, and the importance of informed decision-making in the context of PES.

Investigating the relationship between breast and gynecological cancers and infertility and its treatments: a case-control study

OBJECTIVE

Due to the high prevalence of breast and gynecological cancers among women, it is crucial to identify the risk factors of these cancers. Thus, the present study aimed to evaluate the relationship between breast and gynecological cancers and infertility and its treatments in women suffering from these cancers.

METHODS

This case-control study was conducted with the participation of 400 people (200 women with breast and gynecological cancers and 200 healthy women without a history of cancer) in hospitals and health centers in Tabriz, Iran, in 2022. Data were collected using a four-part researcher-made questionnaire including sociodemographic characteristics, obstetric characteristics, information related to cancer, and information related to infertility and its treatments.

RESULT

s Based on the multivariable logistic regression model and by controlling sociodemographic and obstetric characteristics as possible confounding variables, women with cancer had an infertility history almost four times more than women who did not have a history of cancer (OR = 3.56; 95% CI: 1.36-9.33; P = 0.010). Women with breast cancer had an infertility history five times more than women without a history of breast cancer (OR = 5.11; 95% CI: 1.68-15.50; P = 0.004). The infertility history of women with gynecological cancer was more than three times that of the control group. However, there was no statistically significant difference between the two groups (OR = 3.36; 95% CI: 0.99-11.47; P = 0.053).

CONCLUSION

Infertility and its treatments may be involved in increasing the risk of breast and gynecological cancers.

Rhabdoid tumors in patients conceived following ART: is there an association?

STUDY QUESTION

In children affected by rhabdoid tumors (RT), are there clinical, therapeutic, and/or (epi-)genetic differences between those conceived following ART compared to those conceived without ART?

SUMMARY ANSWER

We detected a significantly elevated female predominance, and a lower median age at diagnosis, of children with RT conceived following ART (RT_ART) as compared to other children with RT.

WHAT IS KNOWN ALREADY

Anecdotal evidence suggests an association of ART with RT.

STUDY DESIGN, SIZE, DURATION

This was a multi-institutional retrospective survey. Children with RT conceived by ART were identified in our EU-RHAB database (n = 11/311 children diagnosed between January 2010 and January 2018) and outside the EU-RHAB database (n = 3) from nine different countries. A population-representative German EU-RHAB control cohort of children with RTs conceived without ART (n = 211) (EU-RHAB control cohort) during the same time period was used as a control cohort for clinical, therapeutic, and survival analyses. The median follow-up time was 11.5 months (range 0-120 months) for children with RT_ART and 18.5 months (range 0-153 months) for the EU-RHAB control cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analyzed 14 children with RT_ART diagnosed from January 2010 to January 2018. We examined tumors and matching blood samples for SMARCB1 mutations and copy number alterations using FISH, multiplex ligation-dependent probe amplification, and DNA sequencing. DNA methylation profiling of tumor and/or blood samples was performed using DNA methylation arrays and compared to respective control cohorts of similar age (n = 53 tumors of children with RT conceived without ART, and n = 38 blood samples of children with no tumor born small for gestational age).

MAIN RESULTS AND THE ROLE OF CHANCE

The median age at diagnosis of 14 individuals with RT_ART was 9 months (range 0-66 months), significantly lower than the median age of patients with RT (n = 211) in the EU-RHAB control cohort (16 months (range 0-253), P = 0.03). A significant female predominance was observed in the RT_ART cohort (M:F ratio: 2:12 versus 116:95 in EU-RHAB control cohort, P = 0.004). Eight of 14 RT_ART patients were diagnosed with atypical teratoid rhabdoid tumor, three with extracranial, extrarenal malignant rhabdoid tumor, one with rhabdoid tumor of the kidney and two with synchronous tumors. The location of primary tumors did not differ significantly in the EU-RHAB control cohort (P = 0.27). Six of 14 RT_ART patients presented with metastases at diagnosis. Metastatic stage was not significantly different from that within the EU-RHAB control cohort (6/14 vs 88/211, P = 1). The incidence of pathogenic germline variants was five of the 12 tested RT_ART patients and, thus, not significantly different from the EU-RHAB control cohort (5/12 versus 36/183 tested, P = 0.35). The 5-year overall survival (OS) and event free survival (EFS) rates of RT_ART patients were 42.9 ± 13.2% and 21.4 ± 11%, respectively, and thus comparable to the EU-RHAB control cohort (OS 41.1 ± 3.5% and EFS 32.1 ± 3.3). We did not find other clinical, therapeutic, outcome factors distinguishing patients with RT_ART from children with RTs conceived without ART (EU-RHAB control cohort). DNA methylation analyses of 10 tumors (atypical teratoid RT = 6, extracranial, extrarenal malignant RT = 4) and six blood samples from RT_ART patients showed neither evidence of a general DNA methylation difference nor underlying imprinting defects, respectively, when compared to a control group (n = 53 RT samples of patients without ART, P = 0.51, n = 38 blood samples of patients born small for gestational age, P = 0.1205).

LIMITATIONS, REASONS FOR CAUTION

RTs are very rare malignancies and our results are based on a small number of children with RT_ART.

WIDER IMPLICATIONS OF THE FINDINGS

This cohort of patients with RT_ART demonstrated a marked female predominance, and a rather low median age at diagnosis even for RTs. Other clinical, treatment, outcome, and molecular factors did not differ from those conceived without ART (EU-RHAB control cohort) or reported in other series, and there was no evidence for imprinting defects. Long-term survival is achievable even in cases with pathogenic germline variants, metastatic disease at diagnosis, or relapse. The female preponderance among RT_ART patients is not yet understood and needs to be evaluated, ideally in larger international series.

STUDY FUNDING/COMPETING INTEREST(S)

M.C.F. is supported by the 'Deutsche Kinderkrebsstiftung' DKS 2020.10, by the 'Deutsche Forschungsgemeinschaft' DFG FR 1516/4-1 and by the Deutsche Krebshilfe 70113981. R.S. received grant support by Deutsche Krebshilfe 70114040 and for infrastructure by the KinderKrebsInitiative Buchholz/Holm-Seppensen. P.D.J. is supported by the Else-Kroener-Fresenius Stiftung and receives a Max-Eder scholarship from the Deutsche Krebshilfe. M.H. is supported by DFG (HA 3060/8-1) and IZKF Münster (Ha3/017/20). BB is supported by the 'Deutsche Kinderkrebsstiftung' DKS 2020.05. We declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Alterations in the expression pattern of some epigenetic-related genes and microRNAs subsequent to oocyte cryopreservation

MicroRNAs (miRNAs) are small non-encoding RNAs that actively regulate biological and physiological processes, and play an important role in regulating gene expression in all cells, especially in most animal cells, including oocytes and embryos. The expression of miRNAs at the right time and place is crucial for the oocyte's maturation and the embryo's subsequent development. Although assisted reproductive techniques (ART) have helped to solve many infertility problems, they cause changes in the expression of miRNA and genes in oocytes and preimplantation embryos, and the effect of these changes on the future of offspring is unknown, and has caused concerns. The relevant genomic alterations commonly imposed on embryos during cryopreservation may have potential epigenetic risks. Understanding the biological functions of miRNAs in frozen maturated oocytes may provide a better understanding of embryonic development and a comparison of fertility conservation in female mammals. With the development of new techniques for genomic evaluation of preimplantation embryos, it has been possible to better understand the effects of ART. The results of various articles have shown that freezing of oocytes and the cryopreservation method are effective for the expression of miRNAs and, in some cases, cause changes in the expression of miRNAs and epigenetic changes in the resulting embryo. This literature review study aimed to investigate the effects of oocyte cryopreservation in both pre-maturation and post-maturation stages, the cryopreservation method and the type of cryoprotectants (CPA) used on the expression of some epigenetic-related genes and miRNAs.

Long-term outcomes for children conceived by assisted reproductive technology

Worldwide, more than 10 million children have been born after assisted reproduction technology (ART), comprising up to 7.9% of children born in Europe and up to 5.1 % of children born in the US in 2018. The short-term outcome for children born after ART is well-known from numerous publications, with higher rates of preterm birth and low birth weight in children born after fresh embryo transfer and higher rates of large for gestational age and high birth weight in children born after frozen embryo transfer compared with children born after spontaneous conception. Higher rates of birth defects in children born after ART have also been shown consistently over time. Studies on long-term health outcomes after ART are scarcer but suggest an increased risk of altered blood pressure and cardiovascular function in children born after ART. In this review, we summarize long-term health outcomes in children born after ART and discuss whether the increased health risks are associated with intrinsic maternal or paternal factors related to subfertility or ART treatments per se. Finally, we speculate where the future will bring us regarding ART treatment strategies and the safety of the mother and child.

Long-Term Effects of ART on the Health of the Offspring

Assisted reproductive technologies (ART) significantly increase the chance of successful pregnancy and live birth in infertile couples. The different procedures for ART, including in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), intrauterine insemination (IUI), and gamete intrafallopian tube transfer (GIFT), are widely used to overcome infertility-related problems. In spite of its inarguable usefulness, concerns about the health consequences of ART-conceived babies have been raised. There are reports about the association of ART with birth defects and health complications, e.g., malignancies, high blood pressure, generalized vascular functional disorders, asthma and metabolic disorders in later life. It has been suggested that hormonal treatment of the mother, and the artificial environment during the manipulation of gametes and embryos may cause genomic and epigenetic alterations and subsequent complications in the health status of ART-conceived babies. In the current study, we aimed to review the possible long-term consequences of different ART procedures on the subsequent health status of ART-conceived offspring, considering the confounding factors that might account for/contribute to the long-term consequences.

Vitrification with Dimethyl Sulfoxide Induces Transcriptomic Alteration of Gene and Transposable Element Expression in Immature Human Oocytes

Despite substantial advancements in the field of cryobiology, oocyte and embryo cryopreservation still compromise developmental competence. Furthermore, dimethyl sulfoxide (DMSO), one of the most commonly used cryoprotectants, has been found to exert potent effects on the epigenetic landscape of cultured human cells, as well as mouse oocytes and embryos. Little is known about its impact on human oocytes. Additionally, few studies investigate the effects of DMSO on transposable elements (TE), the control of which is essential for the maintenance of genomic instability. The objective of this study was to investigate the impact of vitrification with DMSO-containing cryoprotectant on the transcriptome, including on TEs, of human oocytes. Twenty-four oocytes at the GV stage were donated by four healthy women undergoing elective oocyte cryopreservation. Oocytes were paired such that half from each patient were vitrified with DMSO-containing cryoprotectant (Vitrified Cohort), while the other half were snap frozen in phosphate buffer, unexposed to DMSO (Non-Vitrified Cohort). All oocytes underwent RNA sequencing via a method with high fidelity for single cell analysis, and which allows for the analysis of TE expression through Switching Mechanism at the 5'-end of the RNA Transcript sequencing 2 (SMARTseq2), followed by functional enrichment analysis. Of the 27,837 genes identified by SMARTseq2, 7331 (26.3%) were differentially expressed (p < 0.05). There was a significant dysregulation of genes involved in chromatin and histone modification. Mitochondrial function, as well as the Wnt, insulin, mTOR, HIPPO, and MAPK signaling pathways were also altered. The expression of TEs was positively correlated with the expression of PIWIL2, DNMT3A, and DNMT3B, and negatively correlated with age. These findings suggest that the current standard process of oocyte vitrification, involving DMSO-containing cryoprotectant, induces significant transcriptome changes, including those involving TEs.

Cancer risk in children, adolescents, and young adults conceived by ART in 1983-2011

STUDY QUESTION

Do children, adolescents, and young adults born after ART, including IVF, ICSI and frozen-thawed embryo transfer (FET), have an increased risk of cancer compared with children born to subfertile couples not conceived by ART and children from the general population?

SUMMARY ANSWER

After a median follow-up of 18 years, the overall cancer risk was not increased in children conceived by ART, but a slight risk increase was observed in children conceived after ICSI.

WHAT IS KNOWN ALREADY

There is growing evidence that ART procedures could perturb epigenetic processes during the pre-implantation period and influence long-term health. Recent studies showed (non-)significantly increased cancer risks after ICSI and FET, but not after IVF.

STUDY DESIGN SIZE DURATION

A nationwide historical cohort study with prospective follow-up was carried out, including all live-born offspring from women treated with ART between 1983 and 2011 and subfertile women not treated with ART in one of the 13 Dutch IVF clinics and two fertility centers.

PARTICIPANTS/MATERIALS SETTING METHODS

Children were identified through the mothers' records in the Personal Records Database. Information on the conception method of each child was collected through the mother's medical record. In total, the cohort comprises 89 249 live-born children of subfertile couples, of whom 51 417 were conceived using ART and 37 832 were not (i.e. conceived naturally, through ovulation induction, or after IUI). Cancer incidence was ascertained through linkage with the Netherlands Cancer Registry for the period 1989-2019. Cancer risk in children conceived using ART was compared with risk in children born to subfertile couples but not conceived by ART (hazard ratio (HR)) and children from the general population (standardized incidence ratios (SIRs)).

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 358 cancers were observed after a median follow-up of 18 years. Overall cancer risk was not increased in children conceived using ART, when compared with the general population (SIR = 0.96, 95% CI = 0.81-1.12) or with children from subfertile couples not conceived by ART (HR = 1.06, 95% CI = 0.84-1.33). Compared with children from subfertile couples not conceived by ART, the use of IVF or FET was not associated with increased cancer risk, but ICSI was associated with a slight risk increase (HR = 1.58, 95% CI = 1.08-2.31). Risk of cancer after ART did not increase at older ages (≥18 years, HR = 1.26, 95% CI = 0.88-1.81) compared to cancer risk in children not conceived by ART.

LIMITATIONS REASONS FOR CAUTION

The observed increased risk among children conceived using ICSI must be interpreted with caution owing to the small number of cases.

WIDER IMPLICATIONS OF THE FINDINGS

After a median follow-up of 18 years, children conceived using ART do not have an increased overall cancer risk. Many large studies with prolonged follow-up are needed to investigate cancer risk in (young) adults conceived by different types of ART. In addition, international pooling of studies is recommended to provide sufficient power to study risk of specific cancer sites after ART.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by The Dutch Cancer Society (NKI 2006-3631) that funded the OMEGA-women's cohort, Children Cancer Free (KIKA; 147) that funded the OMEGA-I-II offspring cohort. The OMEGA-III offspring cohort was supported by a Postdoc Stipend of Amsterdam Reproduction & Development, and the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health under Award Number R01HD088393. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Assisted reproductive technology and neurodevelopmental outcomes in offspring: a prospective birth cohort study in East China

RESEARCH QUESTION

Is ART associated with adverse neurodevelopmental outcome in 12-month-old offspring compared with those conceived through natural conception?

DESIGN

In this prospective cohort study, 488 infertile women undergoing ART and 1397 women with natural conception were recruited and followed until their offspring were 12 months old. The primary outcome was the neurodevelopment in the offspring. The association between exposure to ART and Gesell developmental scale scores was investigated using multiple linear regression models after adjusting for confounders. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were used to verify the results.

RESULTS

In total, 18 (3.7%) and 40 (2.9%) children in the ART and natural conception groups, respectively, had been diagnosed with neurodevelopmental delay at 12 months of age. It was found that gross motor, adaptive behaviour, language and total development quotient scores were comparable between the groups. Following multivariate linear regression and IPTW, social behaviour development quotient scores were found to be slightly higher in the ART group than the natural conception group. Higher social behaviour development quotient scores in the ART group were also observed in the male and the singleton subgroups.

CONCLUSIONS

At 12 months, offspring born after ART appeared to have similar motor, language and adaptive behaviour skills, and total development quotient scores, to those born after natural conception. However, social behaviour development in 12-month-old infants was slightly higher in those conceived using ART than in naturally conceived offspring, especially in male or singleton infants. These findings may provide new information in evaluating the potential benefits and risks of ART.

Study protocol for a Developmental Epidemiological Study of Children born through Reproductive Technologies (DESCRT)

STUDY QUESTIONS

The primary objective of this study is to determine what parental factors or specific ART may influence the risk for adverse cardiometabolic outcomes among children so conceived and their parents. The secondary objective of this study is to prospectively examine the effects of infertility or ART on the intrauterine environment, obstetric and neonatal outcomes.

WHAT IS KNOWN ALREADY

Pregnancies conceived with ART are at an increased risk of being affected by adverse obstetric and neonatal outcomes when compared to spontaneously conceived (SC) pregnancies among fertile women. Small cohort studies have suggested ART-conceived children may have a higher risk of long-term cardiometabolic disturbances as well. Currently, few studies have compared long-term cardiometabolic outcomes among ART-conceived children and non-IVF treated (NIFT) children, to children conceived spontaneously to parents with infertility (subfertile parents).

STUDY DESIGN SIZE DURATION

The Developmental Epidemiological Study of Children born through Reproductive Technologies (DESCRT) is a prospective cohort study that aims to: establish a biobank and epidemiological cohort of children born to subfertile or infertile parents who either conceived spontaneously (without assistance) or used reproductive technologies to conceive (all offspring were from couples assessed and/or treated in the same institute); prospectively examine the effects of infertility or ART on the intrauterine environment, obstetric and neonatal outcomes; and determine what parental factors or ART may influence the cardiometabolic risk of children so conceived. Pregnancies and resultant children will be compared by mode of conception, namely offspring that were conceived without medical assistance or SC or following NIFT, IVF with fresh embryo transfer or frozen embryo transfer (FET), and by fertilization method (conventional versus ICSI). DESCRT has a Child group evaluating long-term outcomes of children as well as a Pregnancy group that will compare obstetric and neonatal outcomes of children conceived since the commencement of the study. Recruitment started in May of 2017 and is ongoing. When the study began, we estimated that ∼4000 children would be eligible for enrollment.

PARTICIPANTS/MATERIALS SETTING METHODS

Eligible participants are first-trimester pregnancies (Pregnancy group) or children (Child group) born to parents who were evaluated at an infertility center in the University of California, San Francisco, CA, USA who were SC or conceived after reproductive treatments (NIFT, IVF ± ICSI, FET). Children in the Child group were conceived at UCSF and born from 2001 onwards. In the Pregnancy group, enrollment began in November of 2017.The primary outcome is the cardiometabolic health of offspring in the Child group, as measured by blood pressure and laboratory data (homeostatic model assessment for insulin resistance (HOMA-IR), oral glucose disposition). There are several secondary outcome measures, including: outcomes from parental survey response (assessing parent/child medical history since delivery-incidence of cardiometabolic adverse events), anthropomorphic measurements (BMI, waist circumference, skinfold thickness), and laboratory data (liver enzymes, lipid panel, metabolomic profiles). In the Pregnancy group, outcomes include laboratory assessments (bhCG, maternal serum analytes, soluble fms-like tyrosine kinase-1 (sFLT-1), and placental growth factor (PlGF)) and placental assessments (placental volume in the second and third trimester and placental weight at delivery). Importantly, aliquots of blood and urine are stored from parents and offspring as part of a biobank. The DESCRT cohort is unique in two ways. First, there is an extensive amount of clinical and laboratory treatment data: parental medical history and physical examination at the time of treatment, along with ovarian reserve and infertility diagnosis; and treatment specifics: for example, fertilization method, culture O₂ status, embryo quality linked to each participant. These reproductive data will aid in identifying explanatory variables that may influence the primary cardiometabolic outcomes of the offspring-and their parents. Second, the DESCRT control group includes pregnancies and children SC from parents with subfertility, which may help to assess when infertility, as opposed to reproductive treatments, may be affecting offspring cardiometabolic health.

STUDY FUNDING/COMPETING INTERESTS

This study is funded by the National Institutes of Health NICHD (1R01HD084380-01A1). A.J.A. is a shareholder in Carrot and consultant for Flo Health. The other authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

NCT03799107.

TRIAL REGISTRATION DATE

10 January 2019.

DATE OF FIRST PATIENT’S ENROLLMENT

10 May 2017.

Assisted reproductive technology and association with childhood cancer subtypes

OBJECTIVES

To investigate the association between assisted reproductive technology (ART) use and childhood cancer subtype.

STUDY DESIGN

We deployed a cross-sectional survey of 1701 parents of children with cancer about their ART use, demographics, and gestational and perinatal factors. Multivariable logistic regression modeled the association between ART use, birthweight and multiple gestation status with childhood cancer, by subtype.

RESULTS

ART use was highest among children with osteosarcoma relative to children with other cancer types, and this association was statistically significant in multivariable models (OR = 4.4; 95% CI = 1.7-11.3; p = 0.0020). ART use was also elevated among children with hepatoblastoma, but this relationship appeared to be due to the strong associations between ART use and lower birthweight in our sample. No specific ART modality appeared to drive these associations. In univariate models, multiple gestation was associated with a 2.7-fold increased odds of hepatoblastoma (OR = 2.71; 95% CI = 1.14-6.42; p = 0.02) and a 1.6-fold increased odds of neuroblastoma (OR = 1.62; 95% CI = 1.03-2.54; p = 0.03), but these associations were not retained in multivariable models.

CONCLUSIONS

Associations between ART use and hepatoblastoma risk may be attributable to birthweight, a known hepatoblastoma risk factor. ART use may also be associated with osteosarcoma, independent of birthweight, an association not previously observed in studies limited to cancers diagnosed before adolescence. Evaluating long-term health outcomes in children conceived by ART, throughout adolescence and potentially into adulthood, appears warranted.

Risk of genetic and epigenetic alteration in children conceived following ART: Is it time to return to nature whenever possible?

Assisted reproductive technology may influence epigenetic signature as the procedures coincide with the extensive epigenetic modification occurring from fertilization to embryo implantation. However, it is still unclear to what extent ART alters the embryo epigenome. In vivo fertilization occurs in the fallopian tube, where a specific and natural environment enables the embryo's healthy development. During this dynamic period, major waves of epigenetic reprogramming, crucial for the normal fate of the embryo, take place. Over the past decade, concerns relating to the raised incidence of epigenetic anomalies and imprinting following ART have been raised by several authors. Epigenetic reprogramming is particularly susceptible to environmental conditions during the periconceptional period; therefore, unphysiological conditions, including ovarian stimulation, in vitro fertilization, embryo culture, cryopreservation of gametes and embryos, parental lifestyle, and underlying infertility, have the potential to contribute to epigenetic dysregulation independently or collectively. This review critically appraises the evidence relating to the association between ART and genetic and epigenetic modifications that may be transmitted to the offspring.

Assisted reproductive technology: Short- and long-term outcomes

Assisted reproductive technology (ART) includes fertility treatment in which either eggs or embryos are handled outside a female's body to promote successful pregnancies and healthy offspring. Current ART procedures encompass in vitro fertilization with or without intracytoplasmic sperm injection. The most common complication of ART is related to the consequences of multiple pregnancy, which can be prevented or minimized by reducing the number of embryos transferred to the uterus, commonly single embryo transfer. ART has been shown to be variably associated with adverse short- and long-term perinatal outcomes, including cerebral palsy, autism, neurodevelopmental imprinting disorders, and cancer. However, there is uncertainty as to whether reported problems are related to the ART procedure itself, to factors related to infertility, to other medical and environmental factors, or a combination thereof. From a pathophysiological perspective, whether ART alters epigenetic mechanisms of gene expression, leading to later developmental, medical, and behavioral disorders, is an area of active investigation. With the meticulously conducted short- and long-term outcome studies completed so far, overall, and after controlling for multiple gestations and preterm delivery, the results suggest that ART is a safe procedure, offering hope to many parent(s) wishing for a healthy child. This paper highlights ART methods and the risk factors and confounders in the interpretation of short- and long-term outcome data, providing the reader with a means to evaluate findings and conclusions of outcome studies. WHAT THIS PAPER ADDS: Assisted reproductive technology (ART) is a relatively safe procedure. Single embryo implantation optimizes outcome. Informed consent, including the risks and benefits of ART, should be required. Ongoing longitudinal studies are necessary to fully understand ART outcomes.

Current status and reflections on fertility preservation in China

PURPOSE

With the progress of medical technology and renovated conception of fertility, the prospective studies and practice of fertility preservation are drawing more and more attention from medical workers. With the largest population of over 1.4 billion, China makes the experience accumulated in fertility preservation efforts even more relevant. This article summarizes China's experience and shares it with the world to promote the healthy development of fertility preservation.

METHODS

This study was based on multiple Chinese expert consensuses on fertility preservation issued in 2021 and the current national regulations and principles, compared with the latest advice and guidelines issued by global reproductive authorities such as the ASRM and ESHRE. Summarize the experience and reflection of Chinese scholars in the process of fertility preservation.

RESULTS

This study reports on the current situation of fertility preservation in China, sharing the Chinese experience gained in the process of development, and offering Chinese reflections on worrying issues.

CONCLUSION

Fertility preservation is a medical and social issue of reproductive health security, which is conducive to the sound development of the world population and social production.

An examination of mediation by DNA methylation on birthweight differences induced by assisted reproductive technologies

BACKGROUND

Children born after assisted reproductive technologies (ART) differ in birthweight from those naturally conceived. It has been hypothesized that this might be explained by epigenetic mechanisms. We examined whether cord blood DNA methylation mediated the birthweight difference between 890 newborns conceived by ART (764 by fresh embryo transfer and 126 frozen thawed embryo transfer) and 983 naturally conceived newborns from the Norwegian Mother, Father, and Child Cohort Study (MoBa). DNA methylation was measured by the Illumina Infinium MethylationEPIC array. We conducted mediation analyses to assess whether differentially methylated CpGs mediated the differences in birthweight observed between: (1) fresh embryo transfer and natural conception and (2) frozen and fresh embryo transfer.

RESULTS

We observed a difference in birthweight between fresh embryo transfer and naturally conceived offspring of - 120 g. 44% (95% confidence interval [CI] 26% to 81%) of this difference in birthweight between fresh embryo transfer and naturally conceived offspring was explained by differences in methylation levels at four CpGs near LOXL1, CDH20, and DRC1. DNA methylation differences at two CpGs near PTGS1 and RASGRP4 jointly mediated 22% (95% CI 8.1% to 50.3%) of the birthweight differences between fresh and frozen embryo transfer.

CONCLUSION

Our findings suggest that DNA methylation is an important mechanism in explaining birthweight differences according to the mode of conception. Further research should examine how gene regulation at these loci influences fetal growth.

The risks of birth defects and childhood cancer with conception by assisted reproductive technology

STUDY QUESTION

Is there an association between fertility status, method of conception and the risks of birth defects and childhood cancer?

SUMMARY ANSWER

The risk of childhood cancer had two independent components: (i) method of conception and (ii) presence, type and number of birth defects.

WHAT IS KNOWN ALREADY

The rarity of the co-occurrence of birth defects, cancer and ART makes studying their association challenging. Prior studies have indicated that infertility and ART are associated with an increased risk of birth defects or cancer but have been limited by small sample size and inadequate statistical power, failure to adjust for or include plurality, differences in definitions and/or methods of ascertainment, lack of information on ART treatment parameters or study periods spanning decades resulting in a substantial historical bias as ART techniques have improved.

STUDY DESIGN, SIZE, DURATION

This was a population-based cohort study linking ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 1 January 2004 to 31 December 2017 that resulted in live births in 2004-2018 in Massachusetts and North Carolina and live births in 2004-2017 in Texas and New York. A 10:1 sample of non-ART births were chosen within the same time period as the ART birth. Non-ART siblings were identified through the ART mother's information. Children from non-ART births were classified as being born to women who conceived with ovulation induction or IUI (OI/IUI) when there was an indication of infertility treatment on the birth certificate, and the woman did not link to the SART CORS; all others were classified as being naturally conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population included 165 125 ART children, 31 524 non-ART siblings, 12 451 children born to OI/IUI-treated women and 1 353 440 naturally conceived children. All study children were linked to their respective State birth defect registries to identify major defects diagnosed within the first year of life. We classified children with major defects as either chromosomal (i.e. presence of a chromosomal defect with or without any other major defect) or nonchromosomal (i.e. presence of a major defect but having no chromosomal defect), or all major defects (chromosomal and nonchromosomal), and calculated rates per 1000 children. Logistic regression models were used to generate adjusted odds ratios (AORs) and 95% CIs of the risk of birth defects by conception group (OI/IUI, non-ART sibling and ART by oocyte source and embryo state) with naturally conceived children as the reference, adjusted for paternal and maternal ages; maternal race and ethnicity, education, BMI, parity, diabetes, hypertension; and for plurality, infant sex and State and year of birth. All study children were also linked to their respective State cancer registries. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs of cancer by birth defect status (including presence of a defect, type and number of defects), and conception group.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 29 571 singleton children (2.0%) and 3753 twin children (3.5%) had a major birth defect (chromosomal or nonchromosomal). Children conceived with ART from autologous oocytes had increased risks for nonchromosomal defects, including blastogenesis, cardiovascular, gastrointestinal and, for males only, genitourinary defects, with AORs ranging from 1.22 to 1.85; children in the autologous-fresh group also had increased risks for musculoskeletal (AOR 1.28, 95% CI 1.13, 1.45) and orofacial defects (AOR 1.40, 95% CI 1.17, 1.68). Within the donor oocyte group, the children conceived from fresh embryos did not have increased risks in any birth defect category, whereas children conceived from thawed embryos had increased risks for nonchromosomal defects (AOR 1.20, 95% CI 1.03, 1.40) and blastogenesis defects (AOR 1.74, 95% CI 1.14, 2.65). The risk of cancer was increased among ART children in the autologous-fresh group (HR 1.31, 95% CI 1.08, 1.59) and non-ART siblings (1.34, 95% CI 1.02, 1.76). The risk of leukemia was increased among children in the OI/IUI group (HR 2.15, 95% CI 1.04, 4.47) and non-ART siblings (HR 1.63, 95% CI 1.02, 2.61). The risk of central nervous system tumors was increased among ART children in the autologous-fresh group (HR 1.68, 95% CI 1.14, 2.48), donor-fresh group (HR 2.57, 95% CI 1.04, 6.32) and non-ART siblings (HR 1.84, 95% CI 1.12, 3.03). ART children in the autologous-fresh group were also at increased risk for solid tumors (HR 1.39, 95% CI 1.09, 1.77). A total of 127 children had both major birth defects and cancer, of which 53 children (42%) had leukemia. The risk of cancer had two independent components: (i) method of conception (described above) and (ii) presence, type and number of birth defects. The presence of nonchromosomal defects increased the cancer risk, greater for two or more defects versus one defect, for all cancers and each type evaluated. The presence of chromosomal defects was strongly associated with cancer risk (HR 8.70 for all cancers and HR 21.90 for leukemia), further elevated in the presence of both chromosomal and nonchromosomal defects (HR 21.29 for all cancers, HR 64.83 for leukemia and HR 4.71 for embryonal tumors). Among the 83 946 children born from ART in the USA in 2019 compared to their naturally conceived counterparts, these risks translate into an estimated excess of 761 children with major birth defects, 31 children with cancer and 11 children with both major birth defects and cancer.

LIMITATIONS, REASONS FOR CAUTION

In the SART CORS database, it was not possible to differentiate method of embryo freezing (slow freezing versus vitrification), and data on ICSI were only available in the fresh embryo ART group. In the OI/IUI group, it was not possible to differentiate type of non-ART treatment utilized, and in both the ART and OI/IUI groups, data were unavailable on duration of infertility. Since OI/IUI is underreported on the birth certificate, some OI/IUI children were likely included among the naturally conceived children, which will decrease the difference between all the groups and the naturally conceived children.

WIDER IMPLICATIONS OF THE FINDINGS

The use of ART is associated with increased risks of major nonchromosomal birth defects. The presence of birth defects is associated with greater risks for cancer, which adds to the baseline risk in the ART group. Although this study does not show causality, these findings indicate that children conceived with ART, non-ART siblings, and all children with birth defects should be monitored more closely for the subsequent development of cancer.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by grant R01 HD084377 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development, or the National Institutes of Health, nor any of the State Departments of Health which contributed data. M.L.E. reports consultancy for Ro, Hannah, Dadi, Sandstone and Underdog; presidency of SSMR; and SMRU board member. The remaining authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Impact of assisted reproduction techniques on the neuro-psycho-motor outcome of newborns: a critical appraisal

Subfertility and infertility are common problems among couples of reproductive age, and they increasingly require the use of assisted reproductive techniques (ART). Understandably, doubts about the safety of such methods are increasing among future parents. The purpose of this review is to analyse the real impact of ART, such as in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), on the health of the unborn baby; in particular, this work is focussed on the problems related to the neuro-psycho-motor area. Twenty-four studies were reviewed and outcomes investigated were: risk of the onset of neurodevelopmental diseases, worsening of school cognitive performance and risk of developing infantile cerebral palsy (CP) or neurological sequelae. For the first two outcomes, we did not find a correlation with ART; nevertheless, the results of the included studies about risk of CP are discordant and influenced by various confounding factors, such as pre-term birth and multiple pregnancies.IMPACT STATEMENTWhat is already known on this subject? Assisted reproductive techniques (ART) are the main answer for achieving pregnancy in infertile couples. However, a wide number of studies have tried to focus on possible different outcomes in terms of maternal and foetal/new-born health. Regarding this scenario, a peculiar importance is given to diseases affecting the neuro-psycho-motor area of the new-born. Since this group of detrimental pathologies could heavily affect the new-born's quality of life and require costly social facilities, different studies have tried to focus on possible outcomes after ART.What do the results of this study add? This manuscript provides a review of the literature regarding ART procedures and neuro-psycho-motor implication. A review is strongly required due to the importance of collecting evidence from studies with different methodologies.What are the implications of these findings for clinical practice and/or further research? This manuscript provides evidence about the need for wider and more congruent studies regarding neurodevelopment disorders in new-borns after ART procedures. Data are prone to suggest a slight correlation, but several confounding factors can heavily hamper the possibility to draw a firm conclusion about the topic.

Cancer in children born after frozen-thawed embryo transfer: A cohort study

BACKGROUND

The aim was to investigate whether children born after assisted reproduction technology (ART), particularly after frozen-thawed embryo transfer (FET), are at higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception.

METHODS AND FINDINGS

We performed a registry-based cohort study using data from the 4 Nordic countries: Denmark, Finland, Norway, and Sweden. The study included 7,944,248 children, out of whom 171,774 children were born after use of ART (2.2%) and 7,772,474 children were born after spontaneous conception, representing all children born between the years 1994 to 2014 in Denmark, 1990 to 2014 in Finland, 1984 to 2015 in Norway, and 1985 to 2015 in Sweden. Rates for any cancer and specific cancer groups in children born after each conception method were determined by cross-linking national ART registry data with national cancer and health data registries and population registries. We used Cox proportional hazards models to estimate the risk of any cancer, with age as the time scale. After a mean follow-up of 9.9 and 12.5 years, the incidence rate (IR) of cancer before age 18 years was 19.3/100,000 person-years for children born after ART (329 cases) and 16.7/100,000 person-years for children born after spontaneous conception (16,184 cases). Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96 to 1.21, p = 0.18. Adjustment was performed for sex, plurality, year of birth, country of birth, maternal age at birth, and parity. Children born after FET had a higher risk of cancer (48 cases; IR 30.1/100,000 person-years) compared to both fresh embryo transfer (IR 18.8/100,000 person-years), aHR 1.59, 95% CI 1.15 to 2.20, p = 0.005, and spontaneous conception, aHR 1.65, 95% CI 1.24 to 2.19, p = 0.001. Adjustment either for macrosomia, birth weight, or major birth defects attenuated the association marginally. Higher risks of epithelial tumors and melanoma after any assisted reproductive method and of leukemia after FET were observed. The main limitation of this study is the small number of children with cancer in the FET group.

CONCLUSIONS

Children born after FET had a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. The results should be interpreted cautiously based on the small number of children with cancer, but the findings raise concerns considering the increasing use of FET, in particular freeze-all strategies without clear medical indications.

TRIAL REGISTRATION

Trial registration number: ISRCTN 11780826.

Assisted Reproductive Technology and Risk of Childhood Cancers

IMPORTANCE

The number of children born through the use of assisted reproductive technology (ART) has been increasing. These children may have higher risks for epigenetic alteration and adverse perinatal outcomes, which may be associated with childhood cancers.

OBJECTIVE

To determine the associations between different modes of conception and childhood cancers and potential mediation by preterm birth and low birth weight.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide, population-based cohort study included registry data from 2 308 016 eligible parents-child triads in Taiwan from January 1, 2004, to December 31, 2017. A total of 1880 children with incident childhood cancer were identified. Data were analyzed between September 1, 2020, and June 30, 2022.

EXPOSURE

Mode of conception, defined as (1) natural conception, (2) subfertility and non-ART (ie, infertility diagnosis but no ART-facilitated conception), or (3) ART (ie, infertility diagnosis and ART-facilitated conception).

MAIN OUTCOMES AND MEASURES

Diagnosis of childhood cancer according to the International Classification of Childhood Cancers, Third Edition.

RESULTS

The mean (SD) paternal and maternal ages were 33.28 (5.07) and 30.83 (4.56) years, respectively. Of the 2 308 016 children, 52.06% were boys, 8.16% were born preterm, and 7.38% had low birth weight. During 14.9 million person-years of follow-up (median, 6 years [IQR, 3-10 years]), ART conception was associated with an increased risk of any type of childhood cancers compared with natural conception (hazard ratio, 1.58; 95% CI, 1.17-2.12) and subfertility with non-ART conception (hazard ratio, 1.42; 95% CI, 1.04-1.95). The increased cancer risk of children conceived with ART was mainly owing to leukemia and hepatic tumor. The increased cancer risk associated with ART conception was not mediated by preterm birth or low birth weight.

CONCLUSIONS AND RELEVANCE

In this cohort study, children conceived via ART had a higher risk of childhood cancers than those conceived naturally and those born to parents with an infertility diagnosis did not use ART. The increased risk could not be explained by preterm birth or low birth weight.

Assisted reproductive technology and childhood morbidity: a longitudinal cohort study

OBJECTIVE

To evaluate the association between assisted reproductive technology (ART) and offspring morbidity in the first decade of life.

DESIGN

Longitudinal cohort study.

SETTING

Provincial health registry in Quebec, Canada.

PATIENT(S)

A total of 797,654 singleton children born between 2008 and 2019, followed up to 2020.

INTERVENTION(S)

Retrospective, noninterventional study of any ART procedure vs. no ART.

MAIN OUTCOME MEASURE(S)

Childhood morbidity, including hospitalization for infectious, allergic, malignant, and other diseases, assessed using adjusted Cox proportional hazards regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the association with ART. We controlled for unmeasured family-level confounders that were shared among siblings through stratified Cox regression. To do so, we restricted the analysis to 10,097 siblings with discordant exposure to ART and compared the risk of outcomes in exposed vs. unexposed siblings.

RESULT(S)

Compared with no ART, ART was associated with 1.23 times the risk of any hospitalization (95% CI 1.19-1.27), 1.25 times the risk of infectious disease hospitalization (95% CI 1.21-1.29), and 1.25 times the risk of allergy hospitalization (95% CI 1.14-1.38). When we used a sibling design to control for shared genetic and environmental confounders, ART was not associated with a greater risk of childhood hospitalization (HR 0.92, 95% CI 0.78-1.08).

CONCLUSION(S)

ART is associated with an elevated risk of hospitalization up to 11 years of age, but discordant sibling analysis suggests that the association may be due to genetic, environmental, or other shared familial confounders.

Update Knowledge Assessment and Influencing Predictor of Female Fertility Preservation in Oncologists

OBJECTIVE

This study aims to offer an update assessment of the knowledge of Chinese oncologists on female fertility preservation, and identify the determinants that influence the implementation of fertility preservation.

METHODS

A total of 713 Chinese oncologists with different specialties completed the online self-report questionnaire to assess their understanding of fertility risks in cancer treatment, knowledge on female fertility preservation, and perceptions on the barriers in referring patients for fertility preservation.

RESULTS

Although most oncologists were familiar with fertility risk in cancer treatment, half of them lacked the knowledge for reproduction and preservation methods. In the multivariable model, oncologists in a hospital with a specialized reproductive institution, positive precaution for fertility risk, and fertility preservation discussion with patients were significantly correlated with the possibility of fertility preservation referral.

CONCLUSIONS

The intervention targets based on the update evaluation and identified influencing determinants will be helpful for all the oncofertility researchers, oncologists and institutions in future efforts for well-established female fertility preservation services.

Update on the Epigenomic Implication of Embryo Cryopreservation Methods Applied in Assisted Reproductive Technologies With Potential Long-Term Health Effects

Cryopreservation of embryos has become an efficient method in Assisted Reproductive Technologies (ART) and these methods are currently performed at nearly all fertility centers around the globe. Cryopreservation of supernumerary embryos has contributed to an increase in cumulative pregnancy rates and as a consequence, an increasing number of children are being born through these techniques worldwide. However, long-term follow-up studies of children born through ART are scarce, and concerns about the long-term health effects on individuals conceived through ART have been raised. The relevant genomic transformations that occur at the time cryopreservation is usually applied to embryos may have potential epigenetic risks. With advances in multi-omic single cell technologies, new ways to assess the (epi)genomic status during early embryo development have now become feasible. These novel strategies could provide a revolutionary opportunity to understand the actual impact of ART, but also may help future developments aiming at increase both their efficiency and safety. Here we outline insights in current knowledge and research on the impact of cryopreservation on embryos, the possible consequences at epigenetic level and how emerging new high-throughput technologies can be used for their assessment.

Effects of early maternal cancer and fertility treatment on the risk of adverse birth outcomes

BACKGROUND

Early maternal cancer and fertility treatment each increase the risk for adverse birth outcomes, but the joint effect of these outcomes has not yet been reported. Thus, the aim was to assess the individual and joint effect of maternal cancer and fertility treatment on the risk for adverse birth outcomes.

METHODS

This population-based cohort study included 5487 live-born singletons identified in the Danish Medical Birth Register (1994-2016) of mothers with previous cancer (<40 years) recorded in the Danish Cancer Registry (1955-2014). We randomly selected 80,262 live-born singletons of mothers with no cancer <40 years matched to mothers with cancer by birth year and month. We calculated odds ratios (ORs) for preterm birth, low birth weight (LBW) (<2500 g) and small for gestational age (SGA), mean differences in birth weight in grams, and additional cases of preterm birth (gestational age<259 days) per 100,000 person-years. Multiplicative and additive interaction of maternal cancer and fertility treatment was compared with outcomes of children conceived naturally to mothers with no maternal cancer (reference group).

FINDINGS

Among 84,332 live-born singletons, increased ORs for preterm birth were observed among children born to mothers with previous cancer (1·48, 95% confidence interval [CI] 1·33-1.65) or after fertility treatment (1·43, 95% 1·28-1-61), with 22 additional cases of preterm birth among both group of children (95% CI 15-29; 95% CI 14-30). In the joint analyses, the OR for SGA for children born after fertility treatment to mothers with previous cancer was similar to that of the reference group (OR 1·02, 95% CI 0·72-1·44, P for interaction=0·52). Children with both exposures had increased ORs for LBW (1·86, 95% CI 1·17-2·96, P for interaction=0·06) and preterm birth (2·31, 955 CI 1·66-3·20, P for interaction = 0·56), with 61 additional cases of preterm birth (95% CI 27-95, P for interaction=0.26) over that of children in the reference group. The mean birth weight was also lower in children born to mothers with both exposures (-140 g, 95% CI -215; -65) (P for interaction=0.06) but decreased to -22 g (95% CI -76; 31) after adjustment for GA.

INTERPRETATION

Although we did not find any statistically significant additive interaction between maternal cancer and fertility treatment, children born after fertility treatment of mothers with previous cancer were at increased risk for adverse birth outcomes. Thus, pregnant women with both exposures need close follow-up during pregnancy.

FUNDING

The Danish Cancer Society and the Danish Childhood Cancer Foundation.

Association of adverse birth outcomes with in vitro fertilization after controlling infertility factors based on a singleton live birth cohort

Infants conceived with in vitro fertilization (IVF) are exposed to underlying infertility and the IVF process. High risks of adverse birth outcomes (ABOs) were observed among these infants, including preterm birth, low birth weight, macrosomia, being large/small for gestational age (LGA/SGA). It is unclear whether the specific etiology of the rise of ABOs among IVF infants is IVF technology itself or underlying infertility. A total of 9,480 singletons conceived with IVF and 1,952,419 singletons from the general population were obtained in this study. Multivariable logistic regression model was used to assess variations in risk of ABOs according to causes of infertility. Poisson distributions were applied to calculate standardized risk ratios of IVF infants vs. general population after controlling the causes of infertility. Higher risk of preterm birth and low birth weight were observed among parents with polycystic ovary syndrome, endometriosis, uterine and semen abnormalities. Compared to the general population, after excluding the influence of infertility causes, singletons conceived with IVF were at higher risk of macrosomia (SRR = 1.28, 95% CI 1.14-1.44) and LGA (SRR = 1.25, 95% CI 1.15-1.35). The higher risk of ABOs in IVF was driven by both IVF treatments and infertility, which is important for improving IVF treatments and the managing pregnancies and child development.

Fertility trends and comparisons in a historical cohort of US women with primary infertility

BACKGROUND

There is growing interest in long-term outcomes following infertility and infertility treatment. However, there are few detailed longitudinal cohorts available for this work. This study aimed to assemble a historical cohort of women with primary infertility and age-matched controls to evaluate fertility trends, sequelae, and sociodemographic differences. Described here are cohort group characteristics and associated reproductive trends over time.

METHODS

A population-based historical cohort was created using the Rochester Epidemiology Project (REP) record-linkage system (Olmsted County, MN). The cohort included women aged 18-50 with a diagnosis of primary infertility between January 1, 1980, and December 31, 1999. As part of a case-control study, we identified 1:1 age-matched female controls from the same community and era.

RESULTS

A total of 1001 women with primary infertility and 1001 age-matched controls were identified. The women with primary infertility were significantly more likely to be married, college educated, use barrier contraception, and non-smokers compared to age-matched controls. The incidence of primary infertility increased from 14 to 20 per 10,000 person years from 1980-1985 to 1995-1999. Ovulatory dysfunction and unexplained infertility were the most common causes of primary infertility and clomiphene was the most widely used fertility medication. Rates of in vitro fertilization (IVF) increased from 1.8% during 1980-1985 to 26.0% during 1995-1999.

CONCLUSION

Women with primary infertility were found to have unique sociodemographic characteristics compared to age-matched control women, which is consistent with previous research. The incidence of diagnosed primary infertility increased from 1980 to 1999, as did use of IVF.

Preserving Oocytes in Oncofertility†

The prodigious rise of cancer survival rates enables many cancer survivors to live long lives. Therefore, the side effects of cancer treatments as well as the long-term quality of life after cancer have become more relevant. Ovarian toxicity is a major off-target effect of anticancer agents for childhood and young adult female cancer patients. Both chemotherapy and irradiation have been demonstrated to damage the ovary and increase the risks of premature ovarian failure (POF), early menopause, ovarian endocrine disorders, and sub- or infertility. Oncofertility is an emerging and multidisciplinary research and medical field that focuses on providing cancer patients with fertility preservation options. Oocyte quality and quantity are one of the most important factors to determine women's fertility success; therefore, preserving oocytes is paramount for maintaining the ability of young female cancer patients' reproduction after their recovery. This review summarizes peer-reviewed literature on current oocyte preservation options in oncofertility. We describe in-depth oocyte and embryo cryopreservation, ovarian suppression, ovarian tissue cryopreservation, in vitro maturation, ovarian transposition, and adjuvant therapy. Further, we discuss current guidelines and practices of female fertility preservation that cover preserving oocytes.

Reproductive fluids, added to the culture media, contribute to minimizing phenotypical differences between in vitro-derived and artificial insemination-derived piglets

The addition of reproductive fluids (RF) to the culture media has shown benefits in different embryonic traits but its long-term effects on the offspring phenotype are still unknown. We aimed to describe such effects in pigs. Blood samples and growth parameters were collected from piglets derived from in vitro-produced embryos (IVP) with or without RF added in the culture media versus those artificially inseminated (AI), from day 0 to month 6 of life. An oral glucose tolerance test was performed on day 45 of life. We show here the first comparative data of the growth of animals produced through different assisted reproductive techniques, demonstrating differences between groups. Overall, there was a tendency to have a larger size at birth and faster growth in animals derived from in vitro fertilization and embryo culture versus AI, although this trend was diminished by the addition of RFs to the culture media. Similarly, small differences in hematological indices and glucose tolerance between animals derived from AI and those derived from IVP, with a sex-dependent effect, tended to fade in the presence of RF. The addition of RF to the culture media could contribute to minimizing the phenotypical differences between the in vitro-derived and AI offspring, particularly in males.

The Impact of Two Embryo Culture Media, Synthetic Oviduct Fluid and Commercial BO, on pre-and post-Implantation Development of Cloned SAANEN Goat Embryos

BACKGROUND

Somatic cell nuclear transfer (SCNT) is an approach for the propagation of elite animals. In vitro condition, especially the composition of culture media has a profound effect on the developmental competency of in vitro derived e mbryos. There are limited studies evaluating the effect of culture media on SCNT outcomes. To address this gap, we compare the effect of two culture media synthetic oviduct fluid (SOF) vs. commercial bracket-oliphant (BO) on developmental comptenecy.

MATERIALS AND METHODS

In this experimental study, embryos derived from in vitro fertilized (IVF) and SCNT were cultured in both BO and SOF media for 7 days. In addition to the assessment of cleavage and blastocyst on day 3, and 7, the quantitative expression of 16 genes in theresultant blastocysts were assessed. The resultant SCNT blastocysts from SOF and BO groups were also transferred to the synchronized recipient for developmental competency to term.

RESULTS

The blastocyst rate in the BO medium was significantly higher than that of the SOF medium in the SCNT group (P<0.05). All of the examined genes showed increased expression levels in SCNT blastocyst in both media compared to IVF Blastocyst. In the IVF group, Oct4, Bmpr1, and Gcn5 showed significantly higher expression in the SOF medium compared to the BO medium while Akt, Fgfr4, Sox2 showed significantly lower expression in the SOF medium compared to the BO medium. In the SCNT group, Fgfr4, Gcn5, Fzd, Ctnnb, Bmpr1, and Fgfr4 showed significantly higher expression in SOF compared to BO derived blastocyst.

CONCLUSION

It appears that in SCNT blastocysts, gene regulation is less controlled compared to IVF ones, irrespective of the type of medium. In addition, there are differences regarding certain genes expressions between IVF and SCNT derived blastocysts between SOF and BO, reiterating that culture composition affects developmental competency and gene expression.

OUP accepted manuscript

BACKGROUND

Oocyte activation deficiency (OAD) is attributed to the majority of cases underlying failure of ICSI cycles, the standard treatment for male factor infertility. Oocyte activation encompasses a series of concerted events, triggered by sperm-specific phospholipase C zeta (PLCζ), which elicits increases in free cytoplasmic calcium (Ca²⁺) in spatially and temporally specific oscillations. Defects in this specific pattern of Ca²⁺ release are directly attributable to most cases of OAD. Ca²⁺ release can be clinically mediated via assisted oocyte activation (AOA), a combination of mechanical, electrical and/or chemical stimuli which artificially promote an increase in the levels of intra-cytoplasmic Ca²⁺. However, concerns regarding safety and efficacy underlie potential risks that must be addressed before such methods can be safely widely used.

OBJECTIVE AND RATIONALE

Recent advances in current AOA techniques warrant a review of the safety and efficacy of these practices, to determine the extent to which AOA may be implemented in the clinic. Importantly, the primary challenges to obtaining data on the safety and efficacy of AOA must be determined. Such questions require urgent attention before widespread clinical utilization of such protocols can be advocated.

SEARCH METHODS

A literature review was performed using databases including PubMed, Web of Science, Medline, etc. using AOA, OAD, calcium ionophores, ICSI, PLCζ, oocyte activation, failed fertilization and fertilization failure as keywords. Relevant articles published until June 2019 were analysed and included in the review, with an emphasis on studies assessing large-scale efficacy and safety.

OUTCOMES

Contradictory studies on the safety and efficacy of AOA do not yet allow for the establishment of AOA as standard practice in the clinic. Heterogeneity in study methodology, inconsistent sample inclusion criteria, non-standardized outcome assessments, restricted sample size and animal model limitations render AOA strictly experimental. The main scientific concern impeding AOA utilization in the clinic is the non-physiological method of Ca²⁺ release mediated by most AOA agents, coupled with a lack of holistic understanding regarding the physiological mechanism(s) underlying Ca²⁺ release at oocyte activation.

LIMITATIONS, REASONS FOR CAUTION

The number of studies with clinical relevance using AOA remains significantly low. A much wider range of studies examining outcomes using multiple AOA agents are required.

WIDER IMPLICATIONS

In addition to addressing the five main challenges of studies assessing AOA safety and efficacy, more standardized, large-scale, multi-centre studies of AOA, as well as long-term follow-up studies of children born from AOA, would provide evidence for establishing AOA as a treatment for infertility. The delivery of an activating agent that can more accurately recapitulate physiological fertilization, such as recombinant PLCζ, is a promising prospect for the future of AOA. Further to PLCζ, many other avenues of physiological oocyte activation also require urgent investigation to assess other potential physiological avenues of AOA.

STUDY FUNDING/COMPETING INTERESTS

D.G. was supported by Stanford University’s Bing Overseas Study Program. J.K. was supported by a Healthcare Research Fellowship Award (HF-14-16) made by Health and Care Research Wales (HCRW), alongside a National Science, Technology, and Innovation plan (NSTIP) project grant (15-MED4186-20) awarded by the King Abdulaziz City for Science and Technology (KACST). The authors have no competing interests to declare.

The altered immunological status of children conceived by assisted reproductive technology

BACKGROUND

With the increased use of assisted reproductive technology (ART), assessing the potential health risks of children conceived on ART important to public health. Most research in this area has focused on the effects of ART on perinatal, metabolic, and oncological risks in children. Although an increased risk of immune-related diseases has been reported in children born after ART, there are no studies on the immunological status of these children. This study aimed to evaluate the impact of different embryo transfer methods and fertilization strategies on the immune status of the offspring.

METHODS

A total of 69 children born to women treated with ART and a matched control group of 17 naturally conceived (NC) children, all aged from 3 to 6 years, were recruited in the reproductive hospital affiliated to Shandong University. The frequency of immune cells in the peripheral blood was assayed using flow cytometry; plasma cytokine levels were determined by multiplex cytokine immunoassay with human cytokine magnetic beads.

RESULTS

Compared to children born after natural conception, children born after ART had elevated interferon-γ (IFN-γ) levels, regardless of embryo transfer and fertilization strategies. Children in the fresh-embryo transfer group had significantly higher IL-4 levels and a lower ratio of IFN-γ to IL-4 than those in the NC group ((P = 0.004, 10.41 ± 5.76 pg/mL vs 18.40 ± 7.01 pg/mL, P = 0.023, 1.00 ± 0.48 vs 0.67 ± 0.32, respectively). Similar results were shown in either the in vitro fertilization (IVF) group or the intra-cytoplasmic sperm injection (ICSI) group (P < 0.05 and P = 0.08 for IVF; P < 0.05 and P < 0.05 for ICSI, respectively). These alterations in IL-4 concentrations and the ratio of IFN-γ to IL-4 were statistically significantly correlated with supra-physical E₂ (estradiol) levels on the day of hCG administration (R = 0.502, P = 0.017; R = - 0.537, P = 0.010, respectively). Consistently, the frozen embryo transfer did not result in alterations of these immune indicators in the offspring. Overall, there were no significant differences between the ART group and NC group in the frequencies of T cells, B cells, natural killer (NK) cells, CD4⁺T cells, CD8⁺T cells, T helper (T_H)1 cells, T_H17 cells, and regulatory T (T_reg) cells and cytokine levels of IL-10 and IL-17a (all P > 0.05).

CONCLUSIONS

Immunological alterations existed in children born after the use of ART. The elevated E₂ levels before embryo implantation contributed to the increased IL-4 levels in children conceived by fresh embryo transfer. The assessment of immunological alteration is of importance to children conceived by ART for early monitoring and intervention.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer. We conducted a systematic search in the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to June 8, 2020. Altogether, 112 studies were identified. The reviewed studies were heterogeneous in study design, exposure, and outcome classification. In 21 studies (19%), the outcome was any childhood cancer. Of the 91 papers that reported on specific types of cancer, 62% did not report the cancer classification system. The most frequently investigated medication groups were sex hormones (46 studies, excluding fertility medications), and antiinfectives (37 studies). Suggestions for strengthening future pharmacoepidemiologic studies on maternal medication use and childhood cancer relate to choice of cancer classification system, exposure windows, and methods for identification of, and control for, potential confounders.

Polycystic ovary syndrome and offspring risk of congenital heart defects: a nationwide cohort study

STUDY QUESTION

Is maternal polycystic ovary syndrome (PCOS) associated with increased offspring risk of congenital heart defects?

SUMMARY ANSWER

This study does not support a strong association between PCOS and an increased risk of congenital heart defects.

WHAT IS KNOWN ALREADY

In addition to affecting reproductive health, PCOS may involve insulin resistance. Maternal pregestational diabetes is associated with an increased risk of congenital heart defects and therefore PCOS may increase the risk of congenital heart defects in the offspring.

STUDY DESIGN, SIZE, DURATION

In this nationwide cohort study, we used data from Danish health registers collected from 1995 to 2018. The study included 1 302 648 offspring and their mothers.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were live singleton offspring born during the study period. Information on maternal PCOS and offspring congenital heart defects was obtained from the National Patient Register. Logistic regression analysis was used to compute prevalence (odds) ratio (PR) of the association between PCOS and offspring congenital heart defects.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 1 302 648 live-born singletons, 11 804 had a mother with PCOS. Of these, 143 offspring had a congenital heart defect (prevalence 121 per 10 000) as compared with 12 832 among mothers without PCOS (prevalence 99 per 10 000). The adjusted PR was 1.22, 95% CI 1.03-1.44 comparing prevalence of congenital heart defects in offspring of women with PCOS with offspring of women without. After adjusting for the potentially mediating effect of pregestational diabetes, the PR was 1.16, 95% CI 0.98-1.37.

LIMITATIONS, REASONS FOR CAUTION

PCOS may be underdetected in the National Patient Register. However, we expect that the mothers that we identified with PCOS truly had PCOS, thus, the estimated associations are not likely to be affected by this misclassification. The study does not provide evidence to rule out a moderate or weak association.

WIDER IMPLICATIONS OF THE FINDINGS

These findings provide reassurance to clinicians counselling pregnant women with PCOS that the disease does not pose a markedly increased risk of offspring congenital heart defects.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Novo Nordisk Foundation. M.L. reports personal fees from Dansk Lægemiddel Information A/S outside the submitted work. The remaining authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

A review of the types of childhood cancer associated with a medical X-ray examination of the pregnant mother

PURPOSE

For 65 years the interpretation of the statistical association between the risk of cancer in a child and a prior diagnostic X-ray examination of the abdomen of the pregnant mother has been debated. The objections to a direct cause-and-effect explanation of the association vary in their strength, but one of the most notable grounds for controversy is the finding from the first and largest case-control study reporting the association, the Oxford Survey of Childhood Cancers (OSCC), of an almost uniformly raised relative risk (RR) for nearly all of the types of cancer that are most frequent in children. Here we compare the antenatal X-ray associations found in the OSCC for different types of childhood cancer with the results of all other case-control and case-cohort studies appropriately combined in meta-analyses, and we also review the findings of the few cohort studies that have been conducted.

CONCLUSIONS

From the case-control/case-cohort studies other than the OSCC there are consistent and clear elevations of risk for all types of childhood cancer combined, all leukemia, and all cancers except leukemia combined. This compatibility of the findings of the OSCC with those of the combined other studies is less clear, or effectively absent, when some categories containing smaller numbers of incident cases/deaths are considered, but lack of precision of risk estimates due to sparse data presents inferential challenges, although there is a consistent absence of an association for bone tumors. Further, more recent studies almost certainly address lower intrauterine doses, with an anticipated decrease in estimated risks, which could be misleading when comparisons involve a limited number of studies that are mainly from later years, and a similar problem arises when having to employ all types of antenatal X-ray exposures for a study because data for abdominal exposures are absent. The problem of low statistical power is greater for cohort studies, and this, together with other shortcomings identified in the studies, limits the interpretational value of results. The findings of non-medical intrauterine exposure studies are constrained by sparse data and make a limited contribution to an understanding of the association. Certain aspects of the various studies require a need for caution in interpretation, but overall, the appropriate combination of all case-control/case-cohort studies other than the OSCC lends support to the inference that low-level exposure to radiation in utero proportionally increases the risk of the typical cancers of childhood to around the same level.

Possible association between in vitro fertilization technologies and offspring neoplasm

OBJECTIVE

To study the association among fertility treatments, treatment protocol, and offspring neoplasm risk up to the age of 18 years.

DESIGN

A population-based retrospective cohort.

SETTING

Soroka University Medical Center (SUMC), the single tertiary medical center and in vitro fertilization (IVF) unit in southern Israel.

PATIENT(S)

All offspring born at the SUMC between the years 1995 and 2018 after IVF treatment (the exposed group) and offspring conceived spontaneously (the unexposed group).

INTERVENTION(S)

The study was performed at the SUMC, the single tertiary medical center and IVF unit in southern Israel. The exposed and unexposed were matched with a ratio of 1:4, based on maternal age and calendar month of delivery. Data collection included a summary of the couple's medical records, delivery data, and offspring neoplasm diagnoses.

MAIN OUTCOME MEASURE(S)

Offspring neoplasm of any kind and time to diagnosis in each of the groups.

RESULT(S)

A total of 1,583 exposed and 5,874 offspring were included in the study. The incidences of offspring benign neoplasm were 14 (0.9%) versus 21 (0.4%), and the incidences of malignancies were 17 (1.1%) versus 29 (0.5%) among offspring of the IVF and spontaneous groups, respectively. The association between mode of conception and offspring neoplasm risk remained significant after adjusting for confounders, including mode of delivery and pregnancy complications such as hypertensive disorder, gestational diabetes mellitus, and preterm delivery compared with spontaneously conceived offspring. Among the IVF group, the increased risk for neoplasm was found among offspring who were transferred as fresh embryos, at an earlier stage of development (cleavage stage), or after three or more aspirated oocytes.

CONCLUSION(S)

IVF treatment is associated with offspring neoplasm risk; specifically, the risk was greater among offspring who were returned as fresh embryos, at an earlier embryotic stage (cleavage stage), or after three or more aspirated oocytes.

Abnormal Glucose Metabolism in Male Mice Offspring Conceived by in vitro Fertilization and Frozen-Thawed Embryo Transfer

Frozen and thawed embryo transfer (FET) is currently widely applied in routine assisted reproductive technology (ART) procedure. It is of great necessity to assess the safety of FET and investigate the long-term effect including glucose metabolism on FET-conceived offspring. The mouse model is a highly efficient method to figure out the relationship between the process of FET and offspring health. In this study, we obtained mouse offspring of natural conception (NC), in vitro fertilization (IVF), and FET. Glucose and insulin tolerance test (GTT/ITT) were performed on both chow fed or high fat diet (HFD) fed offspring to examine the glucose metabolism status. We detected hepatic PI3K/AKT pathway by western blotting and transcriptome status by RNA-sequencing. Impaired glucose tolerance (IGT) and decreased insulin tolerance were occurred in FET conceived male offspring. After challenged with the HFD-fed, male offspring in FET group performed earlier and severer IGT than IVF group. Furthermore, higher HOMA-IR index and higher serum insulin level post glucose injected in FET-chow group suggested the insulin resistance status. The PI3K/AKT signaling pathway, the major pathway of insulin in the liver, were also disrupted in FET group. Transcriptomics of the liver reveals significantly downregulated in glucose metabolic process and insulin resistance in the FET-chow group. In our study, FET-conceived male mouse offspring presented glucose metabolism dysfunction mainly manifesting insulin resistance. The hepatic insulin signaling pathway were in concordance with reduced glycogen synthesis, increased glycolysis and enhanced gluconeogenesis status in FET-conceived male offspring.

Advanced sperm testing

PURPOSE OF REVIEW

The sensitivity of semen analysis for detection of infertility remains low. Many factors not measured in traditional semen analysis may contribute to male factor infertility. DNA fragmentation, oxidative stress, and sperm aneuploidy are three factors that may contribute further information to the evaluation when semen analysis is inconclusive.

RECENT FINDINGS

DNA fragmentation measures the destruction of and failure to repair damage to DNA. Increased DNA fragmentation has been used as a marker for oxidative stress as well as toxic exposure. The oxidative stress adduct measures DNA aberrations, which sperm cannot repair and has been used to support use of antioxidants. Lastly, the aneuploid sperm frequency is a quantitative measure of deviation from the normal chromosomal complement. Although elevated sperm aneuploid frequency has been associated with recurrent pregnancy loss and implantation failures, barriers remain to its routine use.

SUMMARY

We identified these three adjunctive tests, which have the potential to alter either management or counseling of patients with regards to male factor infertility. Elevated DNA fragmentation or significant sperm aneuploidy may suggest the need for further investigation or further preimplantation genetic testing prior to IVF. The oxidative stress adduct may lend further explanation and improved counseling of the infertile patient.

Modified endometriosis fertility index is more accurate to predict the non-ART pregnancy rate following surgery: a cohort of Chinese women

OBJECTIVE

To examine whether a modified endometriosis fertility index (EFI) can better predict the rate of pregnancy without assisted reproductive technologies (ART) after laparoscopic surgery in infertile Chinese women with endometriosis.

METHODS

564 infertile women undergoing laparoscopy for endometriosis were retrospectively collected from January 2014 to December 2018. 472 patients were used to modify the EFI based on new, optimal cutoffs for its predictor variables. The predictive accuracy of the modified EFI was examined in the other 92 patients.

RESULTS

Among the patients for the EFI modification, the multivariable Cox regression results showed that historical factors made more contribution in predicting non-ART pregnancy rate than surgical factors both in modified EFI (C-index: historical factors 0.617 vs surgical factors 0.558) and original EFI (C-index: historical factors 0.600 vs surgical factors 0.549). No significant relationship between the prior pregnancy and post-operative non-ART pregnancy rates was detected by both modified EFI and original EFI (p = 0.530 and 0.802, respectively). To assess the predictive effect of modified EFI, the two versions of modified EFI not only had higher predictive accuracy (C-index: 0.627 and 0.632) for non-ART pregnancy rates than that of the original EFI (C-index: 0.602) in the patients undergoing surgery during 2014-2017, but also higher than that of the original EFI (C-index: 0.638 and 0.612 vs 0.560) in the externally validated population in 2018.

CONCLUSIONS

A modified EFI based on population-specific optimal cutoffs and weights might be more suitable for estimating the rate of non-ART pregnancy after laparoscopic surgery in infertile women with endometriosis.