Children born to subfertile couples, how are they doing? Evidence from research.

More than 10 million children have been born with assisted reproductive technology (ART) as we begin to enter the third generation of individuals conceived by ART. Here we summarise key messages from an enlarging body of literature regarding their health. Earlier research had pointed towards increases in perinatal, neonatal and neurological risks, such as preterm birth, low birth weight, congenital malformations and cerebral palsy. Many of these risks have continued to persist in most recent work but have shown reduction. Newer research proposes long-term cardiometabolic and endocrine concerns. Fortunately, most reports conclude there is little or no risk of increased childhood malignancy or abnormal neurodevelopment. Moving forward, new research may benefit from changes in comparator groups and a better understanding of infertility per se in ART, and the confounding role it probably plays in many of the known risk associations, to reliably scan the horizon for health threats for individuals born after ART.

National Trends in Preterm Infant Mortality in the United States by Race and Socioeconomic Status, 1995-2020.

Importance: Inequalities in preterm infant mortality exist between population subgroups within the United States. Objective: To characterize trends in preterm infant mortality by maternal race and socioeconomic status to assess how inequalities in preterm mortality rates have changed over time. Design, Setting, and Participants: This was a retrospective longitudinal descriptive study using the US National Center for Health Statistics birth infant/death data set for 12 256 303 preterm infant births over 26 years, between 1995 and 2020. Data were analyzed from December 2022 to March 2023. Exposures: Maternal characteristics including race, smoking status, educational attainment, antenatal care, and insurance status were used as reported on an infant's US birth certificate. Main Outcomes and Measures: Preterm infant mortality rate was calculated for each year from 1995 to 2020 for all subgroups, with a trend regression coefficient calculated to describe the rate of change in preterm mortality. Results: The average US preterm infant mortality rate (IMR) decreased from 33.71 (95% CI, 33.71 to 34.04) per 1000 preterm births per year between 1995-1997, to 23.32 (95% CI, 23.05 to 23.58) between 2018-2020. Black non-Hispanic infants were more likely to die following preterm births than White non-Hispanic infants (IMR, 31.09; 95% CI, 30.44 to 31.74, vs 21.81; 95% CI, 21.43 to 22.18, in 2018-2020); however, once born, extremely prematurely Black and Hispanic infants had a narrow survival advantage (IMR rate ratio, 0.87; 95% CI, 0.84 to 0.91, in 2018-2020). The rate of decrease in preterm IMR was higher in Black infants (-0.015) than in White (-0.013) and Hispanic infants (-0.010); however, the relative risk of preterm IMR among Black infants compared with White infants remained the same between 1995-1997 vs 2018-2020 (relative risk, 1.40; 95% CI, 1.38 to 1.44, vs 1.43; 95% CI, 1.39 to 1.46). The rate of decrease in preterm IMR was higher in nonsmokers compared with smokers (-0.015 vs -0.010, respectively), in those with high levels of education compared with those with intermediate or low (-0.016 vs - 0.010 or -0.011, respectively), and in those who had received adequate antenatal care compared with those who did not (-0.014 vs -0.012 for intermediate and -0.013 for inadequate antenatal care). Over time, the relative risk of preterm mortality widened within each of these subgroups. Conclusions and Relevance: This study found that between 1995 and 2020, US preterm infant mortality improved among all categories of prematurity. Inequalities in preterm infant mortality based on maternal race and ethnicity have remained constant while socioeconomic disparities have widened over time.

Population-based screening methods in biliary atresia: a systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to investigate tested methods of population-based biliary atresia (BA) screening. DESIGN: We searched 11 databases between 1 January 1975 and 12 September 2022. Data extraction was independently done by two investigators. MAIN OUTCOME MEASURES: Our primary outcomes were: sensitivity and specificity of screening method in BA detection, age at Kasai, BA associated morbidity and mortality, cost-effectiveness of screening. RESULTS: Six methods of BA screening were evaluated: stool colour charts (SCCs), conjugated bilirubin measurements, stool colour saturations (SCSs), measurements of urinary sulfated bile acids (USBAs), assessments of blood spot bile acids and blood carnitine measurements.In a meta-analysis, USBA was the most sensitive and specific, with a pooled sensitivity and specificity of 100.0% (95% CI 2.5% to 100.0%) and 99.5% (95% CI 98.9% to 99.8%) (based on one study). This was followed by conjugated bilirubin measurements: 100.0% (95% CI 0.0% to 100.0%) and 99.3% (95% CI 91.9% to 99.9%), SCS: 100.0% (95% CI 0.00% to 100.0%) and 92.4% (95% CI 83.4% to 96.7%), and SCC: 87.9% (95% CI 80.4% to 92.8%) and 99.9% (95% CI 99.9% to 99.9%).SCC reduced the age of Kasai to ~60 days, compared with 36 days for conjugated bilirubin. Both SCC and conjugated bilirubin improved overall and transplant-free survival. The use of SCC was considerably more cost-effective than conjugated bilirubin measurements. CONCLUSION: Conjugated bilirubin measurements and SCC are the most researched and demonstrate improved sensitivity and specificity in detecting BA. However, their use is expensive. Further research into conjugated bilirubin measurements, as well as alternative methods of population-based BA screening, is required. PROSPERO REGISTRATION NUMBER: CRD42021235133.

General health in a cohort of children conceived after assisted reproductive technology in the United Kingdom: a population-based record-linkage study.

BACKGROUND: Assisted reproductive technology use is increasing annually; however, data on long-term child health outcomes including hospital admissions are limited. OBJECTIVE: This study aimed to examine the potential effects of assisted reproductive technology on any and cause-specific hospital admissions unrelated to perinatal diagnoses. STUDY DESIGN: This was a population-based record-linkage study that included a previously established cohort of children born after assisted reproductive technology in the United Kingdom between 1997 and 2009 (n=63,877), their naturally conceived siblings (n=11,343), and matched naturally conceived population controls (n=127,544) linked to their postnatal health outcomes up to March 31, 2016 to provide robust risk estimates of the potential effects of assisted reproductive technology on any and cause-specific hospital admissions unrelated to perinatal diagnoses. In addition, comparison of hospital admissions by type of treatment was made. Cox regression was used to estimate the risk of hospital admission, and negative binomial regression was used to compare the number of hospital admissions per year. RESULTS: This study had 1.6 million person-years of follow-up (mean, 12.9 years; range, 0-19 years), and the mean age at the time of first hospital admission was 6.5 years (range, 0-19 years). Singletons born after assisted reproductive technology had increased risk of any hospital admission compared with naturally conceived population controls (hazard ratio, 1.08; 95% confidence interval, 1.05-1.10) but not naturally conceived siblings (hazard ratio, 1.01; 95% confidence interval, 0.94-1.09). We observed increased risk of diagnoses related to neoplasms and diseases of the respiratory, musculoskeletal, digestive, and genitourinary systems, and lower risk of injury, poisoning, and consequences of external causes compared with naturally conceived population controls. Children born after intracytoplasmic sperm injection had a lower risk of hospital admission compared with those born after in vitro fertilization, although no such differences were observed between children born after fresh embryo transfers and those born after frozen embryo transfers. CONCLUSION: Children born after assisted reproductive technology had greater numbers of hospital admissions compared with naturally conceived population controls. Attenuation of these differences in relation to their naturally conceived siblings suggested that this could be partially attributed to the influence of parental subfertility on child health, increased parental concerns, and an actual increase in morbidity in children born after assisted conception.

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.

Educational attainment in childhood cancer survivors: a meta-analysis.

OBJECTIVE: To assess differences across educational outcomes in survivors of childhood cancer (CCS) compared with peers. DESIGN: Systematic review and meta-analysis of observational studies. DATA SOURCES AND STUDY SELECTION: Medline, EMBASE, ERIC, CINAHL and PsycInfo from inception to 1st August 2018. Any peer reviewed, comparative study with a population of any survivor of childhood cancer, from high-economy countries, reporting outcomes on educational attainment, were selected. RESULTS: 26 studies representing 28 434 CCS, 17 814 matched controls, 6582 siblings and six population studies from 11 high-income countries, which have similar access to education and years of mandatory schooling as reported by the Organisation for Economic Cooperation and Development, were included. CCS were more likely to remain at compulsory level (OR 1.36, 95% CI 1.26 to 1.43) and less likely to complete secondary (OR 0.93, 95% CI 0.87 to 1.0) and tertiary level education (OR 0.87, 95% CI 0.78 to 0.98). They were more likely to require special educational needs (OR 2.47, 95% CI 1.91 to 3.20). Subgroup analyses revealed that survivors, irrespective of central nervous system (CNS) involvement, were less likely to progress onto secondary level compared with cancer-free peers (OR 1.77. 95% CI 1.46 to 2.15; OR 1.19, 95% CI 1.00 to 1.42, respectively). This, however, changed at tertiary level where those with CNS involvement continued to perform worse (OR 0.61, 95% CI 0.55 to 0.68) but those without appeared to perform similarly to their peers (OR 1.12, 95% CI 1.0 to 1.25). CONCLUSIONS: Compared with controls, we have elucidated significant differences in educational attainment in survivors. This is sustained across different countries, making it an international issue. CNS involvement plays a key role in educational achievement. Clinicians, teachers and policymakers should be made aware of differences and consider advocating for early educational support for survivors.

Risks of ovarian, breast, and corpus uteri cancer in women treated with assisted reproductive technology in Great Britain, 1991-2010: data linkage study including 2.2 million person years of observation.

OBJECTIVE: To investigate the risks of ovarian, breast, and corpus uteri cancer in women who have had assisted reproduction. DESIGN: Large, population based, data linkage cohort study. SETTING AND PARTICIPANTS: All women who had assisted reproduction in Great Britain, 1991-2010, as recorded by the Human Fertilisation and Embryology Authority (HFEA). INTERVENTIONS: HFEA fertility records for cohort members were linked to national cancer registrations. MAIN OUTCOME MEASURES: Observed first diagnosis of ovarian, breast, and corpus uteri cancer in cohort members were compared with age, sex, and period specific expectation. Standardised incidence ratios (SIRs) were calculated by use of age, sex, and period specific national incidence rates. RESULTS: 255 786 women contributed 2 257 789 person years' follow-up. No significant increased risk of corpus uteri cancer (164 cancers observed v 146.9 cancers expected; SIR 1.12, 95% confidence interval 0.95 to 1.30) was found during an average of 8.8 years' follow-up. This study found no significantly increased risks of breast cancer overall (2578 v 2641.2; SIR 0.98, 0.94 to 1.01) or invasive breast cancer (2272 v 2371.4; SIR 0.96, 0.92 to 1.00). An increased risk of in situ breast cancer (291 v 253.5; SIR 1.15, 1.02 to 1.29; absolute excess risk (AER) 1.7 cases per 100 000 person years, 95% confidence interval 0.2 to 3.2) was detected, associated with an increasing number of treatment cycles (P=0.03). There was an increased risk of ovarian cancer (405 v 291.82; SIR 1.39, 1.26 to 1.53; AER 5.0 cases per 100 000 person years, 3.3 to 6.9), both invasive (264 v 188.1; SIR 1.40, 1.24 to 1.58; AER 3.4 cases per 100 000 person years, 2.0 to 4.9) and borderline (141 v 103.7; SIR 1.36, 1.15 to 1.60; AER 1.7 cases per 100 000 person years, 0.7 to 2.8). Increased risks of ovarian tumours were limited to women with endometriosis, low parity, or both. This study found no increased risk of any ovarian tumour in women treated because of only male factor or unexplained infertility. CONCLUSIONS: No increased risk of corpus uteri or invasive breast cancer was detected in women who had had assisted reproduction, but increased risks of in situ breast cancer and invasive and borderline ovarian tumours were found in this study. Our results suggest that ovarian tumour risks could be due to patient characteristics, rather than assisted reproduction itself, although both surveillance bias and the effect of treatment are also possibilities. Ongoing monitoring of this population is essential.

Health and disease in children born after assistive reproductive therapies (ART.

In vitro fertilisation (IVF) and other assisted reproductive therapies (ART) offer hope to subfertile couples worldwide. At least 5 million ART children have been born to date. Their health is an issue that is increasingly relevant: first, to those children and young adults themselves; second, to couples considering fertility treatment; and third, to the general population as ART has progressed from experimental treatment to routine practice. Many concerns about the potential risks to these children have been voiced with varying degrees of supportive evidence. This article summarises some key long-term data. Current evidence suggests that ART does increase risk of: higher order pregnancy (with its inherent pre- and perinatal risks); prematurity and low birth weight; congenital malformations in particular of the male urogenital system; imprinting disorders. Reassuringly, evidence points away from an increased overall cancer risk or differences in neurodevelopmental outcomes. Many unknowns remain, including future fertility and cardiovascular risks and risk of cerebral palsy.

Cancer risk among children born after assisted conception.

BACKGROUND: Accurate population-based data are needed on the incidence of cancer in children born after assisted conception. METHODS: We linked data on all children born in Britain between 1992 and 2008 after assisted conception without donor involvement with data from the United Kingdom National Registry of Childhood Tumours to determine the number of children in whom cancer developed before 15 years of age. Cohort cancer rates were compared with population-based rates in Britain over the same period, with stratification for potential mediating and moderating factors, including sex, age at diagnosis, birth weight, singleton versus multiple birth, parity, parental age, type of assisted conception, and cause of parental infertility. RESULTS: The cohort consisted of 106,013 children born after assisted conception (700,705 person-years of observation). The average duration of follow-up was 6.6 years. Overall, 108 cancers were identified, as compared with 109.7 expected cancers (standardized incidence ratio, 0.98; 95% confidence interval [CI], 0.81 to 1.19; P=0.87). Assisted conception was not associated with an increased risk of leukemia, neuroblastoma, retinoblastoma, central nervous system tumors, or renal or germ-cell tumors. It was associated with an increased risk of hepatoblastoma (standardized incidence ratio, 3.64; 95% CI, 1.34 to 7.93; P=0.02; absolute excess risk, 6.21 cases per 1 million person-years) and rhabdomyosarcoma (standardized incidence ratio, 2.62; 95% CI, 1.26 to 4.82; P=0.02; absolute excess risk, 8.82 cases per 1 million person-years), with hepatoblastoma developing in 6 children and rhabdomyosarcoma in 10 children. The excess risk of hepatoblastoma was associated with low birth weight. CONCLUSIONS: There was no increase in the overall risk of cancer among British children born after assisted conception during the 17-year study period. Increased risks of hepatoblastoma and rhabdomyosarcoma were detected, but the absolute risks were small. (Funded by Cancer Research UK and others.).

Unlicensed use of metformin in children and adolescents in the UK.

AIM: Metformin is the most commonly prescribed oral anti-diabetic drug in young people. It is also prescribed for polycystic ovarian syndrome (PCOS) and obesity treatment in adults in an unlicensed fashion. Little is known as to the extent metformin has been used in young people. We investigated the use of metformin in children and adolescents aged 0-18 years in the UK. METHODS: Population-based prescribing data were obtained from the UK IMS Disease Analyzer between January 2000 and December 2010. RESULTS: A total of 2674 metformin prescriptions were issued to 337 patients (80% female) between 2000 and 2010. The prevalence of metformin prescribing increased from 0.03 per 1000 person-years [95% confidence interval (CI) 0.02, 0.05] to 0.16 per 1000 person-years (95% CI 0.12, 0.20) (P= 0.001). There was a steady increase in metformin prescribing in girls aged 16-18 years. There were 290 metformin treated patients (81% female; n= 235) who had at least one diagnosis of diabetes, PCOS or obesity. Among these patients, PCOS was the most common indication for metformin prescribing in girls (n= 120) followed by diabetes. There were 22 patients (7.6%) who received metformin for obesity treatment only. CONCLUSIONS: Prescribing of metformin increased between 2000 and 2010, in particular amongst girls aged 16-18 years. The main indication for metformin prescribing was PCOS. At present, metformin is not licensed for PCOS and obesity treatment in adults or children. As there is a steady increase in the prescribing of metformin in young people, further studies are required to investigate the efficacy and safety of these prescriptions.

Physical health at 5.5 years of age of term-born singletons after intracytoplasmic sperm injection: results of a prospective, controlled, single-blinded study.

OBJECTIVE: To study the health of children born after ICSI and of spontaneously conceived control children at the age of 4-6 years. DESIGN: Prospective, controlled, blinded study. SETTING: Tertiary-care center. PATIENT(S): Two hundred seventy-six term-born singletons conceived by ICSI and 273 matched spontaneously conceived singletons at the age of 5.5 years. INTERVENTION(S): Detailed physical examination, interview of the parents, and collection of data from each child's examination booklet. MAIN OUTCOME MEASURE(S): Biometrical data; current health status; acute, chronic and childhood illnesses; hospitalizations; and surgeries. RESULT(S): Detailed physical examination did not reveal any relevant differences between ICSI and spontaneously conceived children. There were no relevant differences regarding the incidence of childhood illnesses, acute or chronic illnesses, accidents, and surgeries up to the age of 5.5 years. However, a history of undescended testicles was found significantly more often in boys born after ICSI (5.4% vs. 0.7%), with the consequence that they had significantly more urogenital surgery (19.2% vs. 8.9%). Significantly more ICSI children had been hospitalized (37.6% vs. 27.2%), although we did not find any specific reason for the increased hospitalization rate. CONCLUSION(S): Other than an increased risk of undescended testicles and therefore an increase in urogenital surgeries in ICSI boys, the physical health of ICSI children was comparable to that of spontaneously conceived children at the age of 5.5 years.