Academic performance in adolescents born after ART-a nationwide registry-based cohort study

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.

Intelligence, motoric and psychological outcomes in children from different ART treatments: a systematic review and meta-analysis

BACKGROUND

Subtle abnormalities in children's intelligence, motor skills, and psychology from various assisted reproductive treatments (ARTs) might be underdiagnosed. Understanding the prognosis of intelligence, motor skills, and psychology in children from ART would provide parents with reasonable expectations and enable them to plan relevant support to achieve the optimum potential in ART children.

METHODS

We searched PubMed, EMBASE, Ovid, Google Scholar, and Scopus databases until April 13, 2021, to identify relevant studies. Thirty-four studies met the inclusion and exclusion criteria. The meta-analysis employed a standardized mean difference model. The outcome of this study is to compare intelligence quotient (IQ), motoric ability, and behavioral problems between all ARTs, in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) to naturally conceived (NC) children. Subdomains of intelligence based on the Cattell, Horn, and Carroll Model (CHC Model) of cognitive architecture, including fluid reasoning, short-term and working memory, processing speed, visual-spatial ability, long-term memory retrieval, and crystalized intelligence (knowledge), were evaluated and summarized in details. Motor skill was stratified into two domains: gross motoric and fine motoric. Behavioral problem was categorized as externalizing and internalizing behavior.

RESULTS

Meta-analysis showed that verbal intelligence score in IVF toddlers is significantly lower than NC toddlers (p = 0.02); conversely, ICSI toddlers scored significantly higher verbal intelligence score compared to NC toddlers (p = 0.005). Toddlers born after ART had significantly lower non-verbal intelligence score (p = 0.047). IVF toddlers scored significantly lower fine motor score (p = 0.01) compared to naturally conceived toddlers. Based on parent's CBCL, NC toddlers had higher total (p = 0.01) and externalizing behavior (p = 0.001) scores  compared to ART toddlers. Evaluation of full scale IQ and all domains of intelligence in preschool and primary school children revealed that no significant differences exist between ART and NC children. Based on preschool and primary school parents' CBCL, IVF children had significantly lower externalizing behavior score compared to NC children (p = 0.04). Meta-analyses of studies on young adolescents revealed that ART young adolescents scored higher academically than their NC counterparts, including on mathematics (p < 0.00001) and reading or language (p < 0.00001).

CONCLUSIONS

Despite differences in certain aspects, this finding suggests that ART is unlikely to cause negative impacts on children's neurodevelopment.

Adolescent Development and the Parent-Adolescent Relationship in Diverse Family Forms Created by Assisted Reproduction

Assisted reproduction techniques (ARTs) are employed by single individuals and couples who are not otherwise able to conceive spontaneously. While the use of ARTs is increasing, research is lacking on the attempts made by adolescent offspring conceived via ARTs to integrate their ART conception into their identity and negotiate a connection with, and autonomy from, their parents. The present article reviews studies investigating adolescent development and the parent-adolescent relationship in diverse family forms created by ARTs (mainly heterosexual and lesbian parent families), and discusses the results in light of attachment, identity development, and emotional distance regulation theories. Overall, the results indicate that the psychological adjustment of adolescents conceived via ARTs is not undermined by the manner of their conception, and that they enjoy positive relationships with their parents with no difference from those enjoyed by spontaneously conceived adolescents. However, it remains unknown whether the development of a reproductive identity in adolescence is likely to influence adolescents' interest in searching for or contacting their donors, surrogates, and/or donor siblings. The results suggest the relevance of considering the parent-adolescent relationship, disclosure, and identity formation issues when planning psychological counseling and support interventions with ART parents and their adolescent offspring, and emphasize the need to further investigate these aspects in diverse ART families, including single-, gay-, bisexual-, and trans*-parent families.

The Well-Being of Adolescents Conceived Through Medically Assisted Reproduction: A Population-Level and Within-Family Analysis

Medically assisted reproduction (MAR) plays an increasingly important role in the realization of fertility intentions in advanced societies, yet the evidence regarding MAR-conceived children's longer-term well-being remains inconclusive. Using register data on all Finnish children born in 1995-2000, we compared a range of social and mental health outcomes among MAR- and naturally conceived adolescents in population-averaged estimates, and within families who have conceived both through MAR and naturally. In baseline models, MAR-conceived adolescents had better school performance and the likelihood of school dropout, not being in education or employment, and early home-leaving were lower than among naturally conceived adolescents. No major differences were found in mental health and high-risk health behaviours. Adjustment for family sociodemographic characteristics attenuated MAR adolescents' advantage in social outcomes, while increasing the risk of mental disorders. The higher probability of mental disorders persisted when comparing MAR adolescents to their naturally conceived siblings. On average, MAR adolescents had similar or better outcomes than naturally conceived adolescents, largely due to their more advantaged family backgrounds, which underscores the importance of integrating a sociodemographic perspective in studies of MAR and its consequences.

Fetal neurosonography and infant neurobehavior following conception by assisted reproductive technology with fresh or frozen embryo transfer

OBJECTIVE

We aimed to explore fetal cortical brain development by neurosonography in fetuses conceived by assisted reproductive technology (ART), including frozen and fresh embryo transfer (ET), compared with those conceived spontaneously (SC), and to investigate its association with infant neurobehavior at 12 months of age.

METHODS

This was a prospective cohort study of 210 singleton pregnancies, including 70 SC pregnancies, 70 conceived by in-vitro fertilization (IVF) following frozen ET and 70 conceived by IVF after fresh ET. Fetal neurosonography was performed at 32 ± 2 gestational weeks to assess cortical development. Sulci depths were measured offline and normalized by biparietal diameter (BPD). Ages and Stages Questionnaires (ASQ) were completed postnatally, at 12 ± 1 months of corrected age. Neurosonographic findings were adjusted by regression analysis for maternal age, ethnicity, parity, fetal sex and fetal-weight centile and gestational age at scan, and ASQ scores were adjusted for maternal age, ethnicity, parity, educational level and employment status, gestational age at birth, breastfeeding, infant sex and infant age at the ASQ evaluation.

RESULTS

Overall, in comparison to the SC fetuses, fetuses conceived by ART showed statistically significant differences in cortical development, with reduced parieto-occipital sulci depth adjusted for BPD (mean ± SD: fresh ET, 12.5 ± 2.5 vs frozen ET, 13.4 ± 2.6 vs SC, 13.4 ± 2.6, P < 0.001), cingulate sulci depth adjusted for BPD (median (interquartile range (IQR)): fresh ET, 5.8 (4.2-7.4) vs frozen ET, 5.8 (4.1-7.5) vs SC, 6.5 (4.8-7.8), P = 0.001) and calcarine sulci depth adjusted for BPD (median (IQR): fresh ET, 13.5 (10.1-16.1) vs frozen ET, 14.5 (12.1-15.8) vs SC, 16.4 (14.3-17.9), P < 0.001), together with lower Sylvian fissure grading score. Changes in cortical development were more pronounced in the fresh ET than in the frozen ET group. ART infants showed lower ASQ scores as compared to SC infants, particularly in the fresh ET group (mean ± SD global ASQ Z-score: fresh ET, -0.3 ± 0.4 vs frozen ET, -0.2 ± 0.4 vs SC, 0 ± 0.4, P < 0.001).

CONCLUSIONS

Fetuses conceived by ART show a distinctive pattern of cortical development and suboptimal infant neurodevelopment, with more pronounced changes in those conceived following fresh ET. These findings support the existence of in-utero brain reorganization associated with ART and warrant follow-up studies to assess its long-term persistence. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The neurodevelopmental morbidity of children born after assisted reproductive technology: a Nordic register study from the Committee of Nordic Assisted Reproductive Technology and Safety group

OBJECTIVE

To assess the risk of neurodevelopmental disorders in singletons born after the use of assisted reproductive technology (ART) compared with singletons born without the use of ART.

DESIGN

Nordic register-based study.

SETTING

Cross-linked data from Medical Birth Registers and National ART and Patient Registers; liveborn singletons in 1995-2014 in Denmark and Finland, 2005-2015 in Norway, and 1995-2015 in Sweden with follow-up to 2014 (Denmark and Finland) or 2015 (Norway and Sweden).

PATIENTS

A total of 5,076,444 singletons: 116,909 (2.3%) born with and 4,959,535 (97.7%) born without the use of ART (non-ART).

INTERVENTIONS

In vitro fertilization, intracytoplasmic sperm injection, and fresh and frozen embryo transfer.

MAIN OUTCOME MEASURES

The primary outcomes (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes) were learning and motor functioning disorders (F80-F83), autism spectrum disorder (F84), attention-deficit/hyperactivity disorder and conduct disorders (F90-F92), and tic disorders (F95). Crude hazard ratios (HRs) and adjusted hazard ratios (aHRs) with 95% confidence intervals were calculated.

RESULTS

Singletons in the ART cohort had a higher adjusted risk of learning and motor functioning disorders (HR, 1.01 [0.96-1.07]; aHR, 1.17 [1.11-1.24]) and a tendency toward a higher risk of autism spectrum disorder (HR, 1.12 [1.04-1.21]; aHR, 1.07 [0.98-1.16]) and attention-deficit/hyperactivity disorder and conduct disorders (HR, 0.82 [0.77-0.86]; aHR, 1.17 [0.99-1.12]) but not of tic disorders (HR, 1.21 [1.06-1.38]; aHR, 1.17 [0.96-1.27]). No differences in risk were found between children born after in vitro fertilization and intracytoplasmic sperm injection or after fresh and frozen embryo transfer.

CONCLUSIONS

Our findings of only small differences in neurodevelopment between ART and non-ART singletons are reassuring and in line with previous studies.

Academic Performance in Adolescents Born to Mothers With Gestational Diabetes-A National Danish Cohort Study

CONTEXT

The prevalence of gestational diabetes mellitus (GDM) is increasing, and intrauterine hyperglycemia is suspected to affect offspring cognitive function.

OBJECTIVE

We assessed academic performance by grade point average (GPA) in children aged 15 to 16 years at compulsory school graduation, comparing offspring exposed to GDM (O-GDM) with offspring from the background population (O-BP).

METHODS

This register-based, cohort study comprised all singletons born in Denmark between 1994 and 2001 (O-GDM: n = 4286; O-BP: n = 501 045). Standardized and internationally comparable GPAs were compared in univariate and multivariable linear models. Main outcome measures included the adjusted mean difference in GPA. We also analyzed the probability of having a high GPA, a GPA below passing, and no GPA registered.

RESULTS

O-GDM had a GPA of 6.29 (SD 2.52), whereas O-BP had a GPA of 6.78 (SD 2.50). The adjusted mean difference was -0.36 (95% CI, -0.44 to -0.29), corresponding to a Cohen's D of 0.14. O-GDM had a lower probability of obtaining a high GPA (adjusted odds ratio [aOR] 0.68; 95% CI, 0.59 to 0.79), while their risk of obtaining a GPA below passing was similar to O-BP (aOR 1.20; 95% CI, 0.96 to 1.50). O-GDM had a higher risk of not having a GPA registered (aOR 1.38; 95% CI, 1.24 to 1.53).

CONCLUSION

Academic performance in O-GDM was marginally lower than in O-BP. However, this difference is unlikely to be of clinical importance.

Assisted Reproductive Techniques, ADHD, and School Performance

OBJECTIVES

To examine the long-term impact of assisted reproductive techniques (ART) on offspring neurodevelopment, accounting for parental factors and the role of infertility.

METHODS

Linkage of national registers allowed follow-up of >2.4 million children born in Sweden 1986-2012. Information on ART was retrieved from fertility clinics, medical records, and maternal self-report. Attention-deficit/hyperactivity disorder (ADHD) was identified from specialist diagnosis and/or use of medication through 2018. School performance was assessed from records of ninth year final grade averages (0-20) and eligibility for upper secondary school through 2017.

RESULTS

Children conceived with ART had lower risk of ADHD (hazard ratio 0.83; 95% confidence interval [CI]: 0.80 to 0.87) and did better in school (grade mean difference 1.15; 95% CI: 1.09 to 1.21 and eligibility odds ratio 1.53; 95% CI: 1.45 to 1.63) compared with all other children. Differences in parental characteristics explained and even reversed associations, whereas no disadvantage was seen when the comparison was restricted to children of couples with known infertility (adjusted hazard ratio 0.95; 95% CI: 0.90 to 1.00, adjusted mean difference 0.05; 95% CI: -0.01 to 0.11, and adjusted odds ratio 1.03; 95% CI: 0.96 to 1.10). Among children conceived with ART, there was furthermore no indication that intracytoplasmic sperm injection (compared with standard in vitro fertilization) or frozen (compared with fresh) embryo transfer had any adverse influence.

CONCLUSIONS

With this nationwide, long-term follow-up, we provide additional reassurance concerning offspring neurodevelopment after use of ART, finding no indication for concern about risk of ADHD or school performance in adolescence.

Medically assisted reproduction and parent-child relationships during adolescence: evidence from the UK Millennium Cohort Study

STUDY QUESTION

Do the parent–child relationships of adolescents born after medically assisted reproduction (MAR) using the parents’ own gametes differ from those of adolescents born after natural conception (NC)?

SUMMARY ANSWER

MAR and NC families have similar parent–child relationships in terms of closeness and conflict frequency, except that MAR mothers report being closer to their children than NC mothers.

WHAT IS KNOWN ALREADY

Prior work on parent–child relationships during childhood has reported mixed findings. While some studies have documented no differences between MAR and NC families, others have shown that MAR families have greater levels of warmth and positive feelings than NC families. Evidence on parent–child relationships during the adolescent period is generally positive but is limited because of the small number of existing studies and the reliance on small samples.

STUDY DESIGN, SIZE, DURATION

This work is based on the UK Millennium Cohort Study, whose study members were born in 2000–2002. The analyses focused on Sweep 6 which was collected when cohort members were around 14 years old. We also relied on variables collected in Sweep 1, when cohort members were aged around 9 months, to account for characteristics that could confound or mediate the relationship between MAR and our outcomes. The attrition rate between Sweeps 1 and 6 was 36.7%.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The final sample consisted of 10 233 cohort members, 320 of whom were conceived with the help of MAR (3.1%). A total of six dependent variables were used to measure, when the cohort members were around 14 years old, levels of parent–child closeness and conflict, reported separately by the mother, the father and the cohort member. Linear models were used to analyse the association between parent–child relationships before and after adjustment for socio-demographic characteristics and mental health.

MAIN RESULTS AND THE ROLE OF CHANCE

Sweep 6 achieved a response rate of 76.3% of the eligible sample. The results show that, on average, MAR and NC families had similar parent–child relationships in terms of closeness and conflict frequency. The only difference was that MAR mothers reported being closer to their children than NC mothers both before (β = 0.149, P < 0.05) and after (β = 0.102, P < 0.1) adjustment for family socio-demographic characteristics and mental health.

LIMITATIONS, REASONS FOR CAUTION

The outcome variables are self-reported by each of the respondents and could be subject to social desirability bias. Second, some parents may have not reported they conceived through donor insemination, which could result in the analytical sample including a small subset of children who were not genetically related to their parents. Third, the data did not include information about whether the children were aware of their conception mode, since the Millennium Cohort Study did not collect information on MAR disclosure. Moreover, they did not allow us to study other aspects of parent–child relationships. Finally, as we observed parent–child relationships at only one moment in time; we were unable to test whether they changed over time.

WIDER IMPLICATIONS OF THE FINDINGS

The results suggest that the difficulties and the stress parents underwent to conceive through MAR did not translate into more difficult parent–child relationships during adolescence. Given the increasing number of children conceived via MAR, the finding that MAR and NC families had similar parent–child relationships in terms of closeness and conflict frequency is reassuring.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by European Research Council agreement n. 803959 (MARTE to A.G.). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

n/a

School performance in children born after ICSI

STUDY QUESTION

Do children conceived after ICSI have similar school performance as children born after IVF?

SUMMARY ANSWER

Children born after ICSI have similar school performance compared to children born after IVF.

WHAT IS KNOWN ALREADY

Studies concerning the cognitive skills of children born after ICSI have shown diverging results.

STUDY DESIGN, SIZE, DURATION

This nationwide, register-based cohort study included all singleton children born after ICSI (n = 6953), IVF (n = 11 713) or spontaneous conception (SC) (n = 2 022 995), in Sweden between 1985 and 2006.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Singleton children born after ICSI were identified in national IVF registers, cross-linked with the Medical Birth Register (MBR), the National Patient Register (NPR) and the Swedish Cause of Death Register (CDR) for characteristics and medical outcomes. Data on school performance, parental education and other parental characteristics were obtained through cross-linking to the National School Registry and to Statistics Sweden. The main control group, which consisted of children born after IVF, was identified in the national IVF registries while the second control group, consisting of children born after SC, was identified from the MBR. Simple and multivariable linear regression was used for analysis of continuous variables, and logistic regression was used for the analysis of binary outcomes. Adjustments were made for sex, year of birth, maternal smoking during pregnancy, parental age, parity, parental region of birth, parental level of education and frozen embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

In the adjusted analyses, there was no significant difference between ICSI and IVF children for total score (adjusted odds ratios (AORs) 1.03; 95% CI −0.22 to 2.28; P = 0.11), specific subjects, qualifying for secondary school (AOR 1.02; 95% CI 0.82–1.26; P = 0.87) or poor school performance (AOR 0.92; 95% CI 0.75−1.14; P = 0.47). In the third grade, children born after ICSI had a significantly lower chance of passing all of the subtests in Mathematics (AOR 0.89; 0.83–0.96; P = 0.002) and Swedish (AOR 0.92; 0.85–0.99; P = 0.02) compared to children born after SC. When cross-linking children with missing data on school performances (2.1% for ICSI, 2.0% for IVF and 2.3% for SC) with the Cerebral Palsy Follow-up Register (CPUP) for cerebral palsy, 2.7% of ICSI children, 5.7% of IVF children and 1.7% of SC children without registered education were found. When cross-linking children with missing data on school performances with the NPR for mental retardation, 29.9% of ICSI children, 32.6% of IVF children and 35.0% of SC children with missing data were registered under such a diagnosis.

LIMITATIONS, REASONS FOR CAUTION

The main limitation was that test scores were missing in a small percentage in both ICSI and IVF children. Although we were able to cross-link this subpopulation with the CPUP and the NPR, these diagnoses only partly explained the missing scores. Other limitations were unmeasured and unknown possible confounders, such as information about infertility diagnoses and indication for ICSI, were not available.

WIDER IMPLICATIONS OF THE FINDINGS

These findings are important to most countries where IVF and ICSI are used since there may be differences in choice of procedure. In recent years, there has been an increasing trend towards using ICSI not only for treatment of male infertility but also when the sperm quality is normal. Our results indicate that the school performance of children born after ICSI is reassuring.

STUDY FUNDING/COMPETING INTEREST(S)

Financial support was received through Sahlgrenska University Hospital (ALFGBG – 70 940), Hjalmar Svensson Research Foundation and Nordforsk, project number 71 450. None of the authors declare any conflict of interest.

TRIAL REGISTRATION NUMBER

N/A

Sixth grade academic achievement among children conceived with IVF: a population-based study in Texas, USA

PURPOSE

To compare academic achievement in reading and mathematics at the end of sixth grade and progress from third to sixth grade by children conceived with in vitro fertilization (IVF) to those conceived naturally.

METHODS

This was a retrospective population-based cohort study of IVF-conceived singleton and twin children who took the 3rd grade and 6th grade public school standardized reading and mathematics testing in Texas.

RESULTS

There were 6623 children with reading scores in both the third and sixth grades and 6374 children with mathematics scores in both the third and sixth grades. Mean (± SE) scaled test scores for IVF and control singleton children for reading were 1544.6 ± 3.4 and 1527.7 ± 1.9, respectively, in third grade and 1701.2 ± 3.6 and 1681.0 ± 2.0, respectively, in sixth grade; for mathematics, the scores were 1564.4 ± 3.7 and 1548.9 ± 2.1, respectively, in third grade and 1774.0 ± 4.2 and 1752.0 ± 2.3, respectively, in sixth grade. In multivariate models, singleton IVF children scored significantly higher than control children in reading and mathematics, averaging 17.7 ± 4.0 points and 20.1 ± 4.1 points higher, respectively, in reading in third and sixth grades and 17.8 ± 4.4 points and 25.0 ± 4.8 points higher, respectively, in mathematics in third and sixth grades.

CONCLUSIONS

Children conceived with IVF and aged 8-9 years and aged 10-12 years performed as well on third and sixth grade reading and mathematics assessments as their counterparts conceived naturally.

Ninth-grade school achievement in Danish children conceived following fertility treatment: a population-based cohort study

OBJECTIVE

To assess whether academic achievement among children conceived following fertility treatment is different from that of children born to fertile women while also considering the underlying infertility.

DESIGN

Population-based cohort study.

SETTING

Denmark.

PATIENT(S)

The study population consisted of all 154,536 firstborn, live-born, singleton children in Denmark between 1995 and 2000 who completed their ninth grade with an examination.

INTERVENTION(S)

The Danish Infertility Cohort was used to identify children conceived after fertility treatment (n = 10,099), and information on mean school marks was obtained from Statistics Denmark.

MAIN OUTCOME MEASURE(S)

Linear regression models were used to estimate mean differences (MDs) and 95% confidence intervals (CIs). Multiple logistic regression models were used to estimate odds ratios (OR) and 95% CI of not passing the ninth-grade examination.

RESULTS

The crude overall mean marks for children conceived after the various fertility treatment procedures were in general higher than in children born to fertile women. However, after adjustment for potential confounders, the overall mean marks were statistically significantly lower for children conceived after the various fertility treatment procedures (e.g., any fertility treatment: MD -0.13; 95% CI -0.18, -0.08) compared with children born to fertile women. Further, children conceived after any fertility treatment had a statistically significant lower crude likelihood of not passing the ninth-grade examination (OR 0.66; 95% CI 0.53, 0.81) compared with children born to fertile women, whereas no difference was observed in the confounder adjusted analyses (OR 1.15; 95% CI 0.89, 1.49). When children born to women requiring fertility assistance but without fertility treatment in the index pregnancy were used as a reference group, no differences in the adjusted overall mean marks and the likelihood of not passing the ninth grade with an examination were observed.

CONCLUSION

Our findings indicate that fertility treatment per se is not associated with lower school marks and the likelihood of not passing the ninth grade with an examination. Hence, we suggest that factors related to both fertility problems and cognitive development may more likely explain the slightly lower academic performance (i.e., modest lower mean marks) among children conceived after fertility treatment.

Is Intracytoplasmic Sperm Injection the Solution for all in Unexplained Infertility?

Intracytoplasmic sperm injection (ICSI) was first introduced as a supplemental method to conventional in vitro fertilization (c-IVF) for couples with severe male factor infertility to overcome the poor fertilization rate, while its indications expanded in current clinical practice and gained worldwide popularity. However, ICSI is invasive and crosses all natural barriers, raising several unresolved concerns regarding procedure-dependent and procedure-independent risks, as well as the characteristic of being labor-intensive and more expensive than c-IVF. This review is aimed to draw readers' attention, to the widespread use of ICSI worldwide, with its effectiveness in different indications of infertility, especially in those with unexplained infertility, as well as the cost-effectiveness of the ICSI-for-all strategy. Also, we covered current evidence on the short- and long-term safety of children born thanks to ICSI-aided conception. Further well-designed, adequately powered, and randomized controlled clinical trials are absolutely needed to arrive at a consensus on the use of ICSI over c-IVF in different populations.

Cognitive and behavioural outcome of children born after IVF at age 9 years

STUDY QUESTION

Do ovarian stimulation (OS) and the in vitro laboratory procedures affect offsprings' cognitive and behavioural outcome at 9 years?

SUMMARY ANSWER

OS and the in vitro laboratory procedures or the combination of both were not associated with cognitive and behavioural outcome at age 9 years.

WHAT IS KNOWN ALREADY

ART is not associated with an adverse short-term developmental outcome of the offspring, but limited knowledge is available on the offspring's long-term neurodevelopmental condition.

STUDY DESIGN, SIZE, DURATION

A 9-year longitudinal, assessor-blinded, prospective follow-up study of 169 out of 215 singletons (79%) born between March 2005 and December 2006 was performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Singletons born following IVF or ICSI with OS (n = 57), born after modified natural cycle IVF/ICSI (MNC-IVF/ICSI; n = 46) and born after natural conception to subfertile couples (Sub-NC; n = 66), were assessed at 9 years. This study design, with two ART groups and a subfertile reference group, allows for disentangling the effects of OS and ART procedures on developmental outcome. Cognitive outcome was evaluated with the Wechsler abbreviated scale of intelligence and the NEPSY-II. Behaviour was assessed with the child behaviour checklist (CBCL) and teacher report form (TRF). Univariable analyses and multiple linear regression models were used.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant difference in intelligence quotient (IQ) scores between ART groups (mean IQ (95% CI): OS 114.8 (83.2-142.6); MNC 114.0 (90.2-140.8); Sub-NC 115.4 (87.9-141.2), P = 0.746). Multivariable analyses did not reveal a statistically significant association between ART group and total, verbal and performance IQ. CBCL and TRF scores did not differ significantly between ART groups (P = 0.090 and 0.507, respectively). Multivariable analyses did not demonstrate a statistically significant association between ART group and CBCL and TRF total, or internalising and externalising T-scores. No significant correlations between time to pregnancy (TTP)-a proxy for the severity of parental subfertility-and outcome measures were found (Spearman rho between -0.050 and 0.049, NS), which was confirmed with multivariable analyses.

LIMITATIONS, REASONS FOR CAUTION

The attrition rate of 21% may be considered as a limitation of the study; however, after a follow-up period of 9 years, this rate is generally considered acceptable, and there were no significant differences in background characteristics between children with and without follow-up, making an attrition-related selection bias less likely. Another limitation of the study is the relatively small sample size, which could contribute to selection bias, hamper generalizability to the ART population and lead to false negative findings as a result of underpowering. An a priori power analysis on total IQ indicated that the OS-IVF/ICSI and Sub-NC groups should contain 64 children, confirming that our study including 57 and 66 children, respectively, was slightly underpowered.

WIDER IMPLICATIONS OF THE FINDINGS

Our study indicated that OS and the in vitro laboratory procedures or the combination of both and TTP were not associated with cognitive and behavioural outcome at 9 years. These are reassuring results for both parents and clinicians involved in ART.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financially supported by the University Medical Center Groningen (UMCG), two graduate schools of the UMCG (BCN and SHARE) and the Cornelia Stichting. The sponsors of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare.

Fathers of children conceived using ART have higher cognitive ability scores than fathers of naturally conceived children

STUDY QUESTION

Does paternal cognitive ability differ for children conceived with and without assisted reproductive technology (ART)?

SUMMARY ANSWER

Young fathers of ART conceived children tend to score cognitively below their same-age natural conception (NC) counterparts and older (above 35) fathers of ART conceived children tend to score above.

WHAT IS KNOWN ALREADY

Cognitive ability is a genetically and socially transmitted trait, and If ART and NC children have parents with different levels of this trait, then this would in itself predict systematic differences in child cognitive outcomes. Research comparing cognitive outcomes of children with different modes of conception finds conflicting results, and studies may be influenced by selection and confounding.

STUDY DESIGN, SIZE, DURATION

This is a population-based study based on Norwegian data, combining information from the Medical Birth Registry (births through 2012), military conscription tests (birth cohorts 1955–1977) and the population registry. These data allow us to compare the cognitive ability scores of men registered as the father of an ART-conceived child to the cognitive abilities of other fathers and to average scores in the paternal birth cohorts.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

The population level study included 18 566 births after ART (5810 after ICSI, 12 756 after IVF), and 1 048 138 NC births. It included all Norwegian men who received a cognitive ability score after attending military conscription between 1973 and 1995. This constituted 614 827 men (89.4% of the male birth cohorts involved). An additional 77 650 unscored males were included in sensitivity analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Paternal cognitive level was assessed using intelligence quotients (IQ) converted from stanine scores on a three-part cognitive ability test with items measuring numeracy, vocabulary and abstract thought (Raven-like matrices). ART fathers averaged 1.95 IQ points above the average of their own birth cohort (P-value &lt; 0.0005) and 1.83 IQ points above NC fathers in their own birth cohort (P &lt; 0.0005). Comparisons of the IQ of ART fathers to those of NC fathers of similar age and whose children were born in the same year, however, found average scores to be more similar (point estimate 0.24, P = 0.023). These low average differences were found to differ substantially by age of fatherhood, with young ART fathers scoring below their NC counterparts and older ART fathers scoring above their NC counterparts.

LIMITATIONS, REASONS FOR CAUTION

We do not have information on maternal cognition. We also lack information on unsuccessful infertility treatments that did not result in a live birth.

WIDER IMPLICATIONS OF THE FINDINGS

Paternal cognitive ability of ART children differs from that of NC children, and this difference varies systematically with paternal age at child birth. Selection effects into ART may help explain differences between ART and NC children and need to be adequately controlled for when assessing causal effects of ART treatment on child outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

This research has also been supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 262700 (Centre for Fertility and Health). It has also been supported by the Research Council of Norway’s Project 236992 (Egalitarianism under pressure? New perspectives on inequality and social cohesion). There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A

The demographics of assisted reproductive technology births in a Nordic country

STUDY QUESTION

What are the socio-demographic characteristics of families in Norway who have children after assisted reproductive technology (ART), and have these characteristics changed over time?

SUMMARY ANSWER

Parents who conceive through ART in Norway tend to be advantaged families, and their socio-demographic profile has not changed considerably over the period 1985-2014.

WHAT IS KNOWN ALREADY

A small number of studies show that couples who conceive through ART tend to be socio-economically advantaged.

STUDY DESIGN, SIZE, DURATION

Norwegian Population Register, the Medical Birth Register and the national data bases were linked to study all live births in Norway between 1985 and 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The sample consisted of 1 757 768 live births. Simple bivariate analyses were performed to describe the socio-demographic characteristics of parents who conceived through ART and changes in these characteristics over the time period 1985-2014. We used linear probability models to estimate the association between parental income and giving birth after ART from 2000 to 2014, before and after adjustment for maternal age at delivery, education and area of residence.

MAIN RESULTS AND THE ROLE OF CHANCE

Parents conceiving through ART were more likely to be older, with the highest levels of income and education, and married. Their socio-demographic profiles did not change considerably during the period 1985-2014. In the unadjusted model, parents belonging to the top income quartile were 4.2 percentage points more likely (95% CI: 4.1 to 4.3) to have conceived through ART than parents who belonged to the bottom income quartile. Adjustment for maternal age only partially reduced the income disparities (for the top income quartile by 35% (β = 2.7 with 95% CI: 2.5 to 2.8)). Additional adjustment for maternal education, marital status and area of residence did not further attenuate the associations.

LIMITATIONS, REASONS FOR CAUTION

The data does not enable us to tell whether the lower numbers of children conceived through ART amongst more disadvantaged individuals is caused by lower success rates with ART treatment, lower demand of ART services or barriers faced in access to ART. The study focuses on Norway, a context characterised by high subsidisation of ART services.

WIDER IMPLICATIONS OF THE FINDINGS

Even though in Norway access to ART services is highly subsidised, the results highlight important and persisting social inequities in use of ART. The results also indicate that children born after ART grow up in resourceful environments, which will benefit their development and well-being.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by European Research Council agreement n. 803959 (to A.G.), by Economic and Social Research Council grant ES/M001660/1 and by the Research Council of Norway through its Centres of Excellence funding scheme, project number 262700. The authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Third grade academic achievement among children conceived with the use of in vitro fertilization: a population-based study in Texas

OBJECTIVE

To evaluate if there are differences in standardized testing results at the end of third grade between children conceived with the use of in vitro fertilization (IVF) and those conceived spontaneously.

DESIGN

Retrospective population-based cohort.

SETTING

Texas public school system.

PATIENT(S)

Singleton and twin children 8-9 years of age who took the third-grade public school standardized testing in Texas from 2012 to 2018.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Standardized testing in reading and mathematics.

RESULT(S)

After exclusions, there were 6,970 IVF and 12,690 non-IVF children with reading scores and 6,973 IVF and 12,729 non-IVF children with mathematics scores. IVF children scored significantly higher in reading (singletons: 1,543 ± 2 vs. 1,525 ± 1; twins: 1,534 ± 2 vs. 1,504 ± 5 [mean ± SE]), and mathematics (singletons: 1,566 ± 2 vs. 1,550 ± 1; twins: 1,557 ± 2 vs. 1,529 ± 5). Children of mothers ≥30 years of age scored consistently higher than children of mothers 18-29 years of age. The differences were of similar magnitude between IVF and control children for older ages, but not significant for IVF. Within the IVF group, there were no significant differences between children born from fresh versus froze-thawed embryos.

CONCLUSION(S)

Children of ages 8-9 years who were conceived with the use of IVF performed as well on third-grade reading and math assessments as their counterparts who were conceived spontaneously. We also found consistent racial and ethnic differences, gender differences, and beneficial effects of older maternal age. Because we were not able to adjust adequately for socioeconomic status and other confounding factors, which may explain some of the observed differences, we conclude that there is no negative effect of IVF conception on academic achievement in third grade.

Long-term health of children conceived after assisted reproductive technology

The aim of this narrative review is to summarize the present knowledge on long-term outcome of children born after assisted reproductive technologies (ART). The main outcomes covered are neurodevelopment including cerebral palsy, cognitive development, attention deficit hyperactivity disorder and autism spectrum disease, growth, cardiovascular function, diabetes type 1, asthma, malignancies, and reproductive health. Results have mainly been obtained from systematic reviews/meta-analyses and large registry studies. It has been shown that children born after ART, when restricted to singletons, have a similar outcome for many health conditions as their spontaneously conceived peers. For some outcomes, particularly cardiovascular function and diabetes, studies show some higher risk for ART singletons or subgroup of ART singletons. The fast introduction of new ART techniques emphasizes the importance of continuous surveillance of children born after ART.

Intracytoplasmic sperm injection for male infertility and consequences for offspring

Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

Fertility treatment among women with asthma: a case-control study of 3689 women with live births

Asthma has been linked with prolonged time to pregnancy. Our aim was to explore a possible association between asthma and need for fertility treatment among women with live births.All women enrolled in the Management of Asthma during Pregnancy (MAP) programme at Hvidovre Hospital, Denmark were each matched with the next three consecutive women giving birth at Hvidovre Hospital. Information from the Danish National Assisted Reproductive Technology (ART) registry was cross-linked with the Danish Medical Birth registry to identify live births. The primary outcome of interest was births following fertility treatment.Our sample comprised pregnancies from asthmatic mothers (n=932, described as "cases") and non-asthmatic mothers (n=2757, described as "controls"), with 12% (n=114) and 8% (n=212), respectively, having had fertility treatment (OR 1.67, 95% CI 1.32-2.13; p<0.001). This association remained statistically significant after adjusting for confounders, including body mass index (OR 1.31, 95% CI 1.00-1.70; p=0.047). In women ≥35 years, 25% of cases (n=63) and 13% of controls (n=82) received fertility treatment (OR 2.12, 95% CI 1.47-3.07; p<0.001), which also remained statistically significant after adjusting for confounders (OR 1.65, 95% CI 1.11-2.46; p=0.013).A higher proportion of the births from asthmatic mothers involved fertility treatment compared to non-asthmatic mothers, not least among women aged ≥35 years.

Academic performance in adolescents aged 15-16 years born after frozen embryo transfer compared with fresh embryo transfer: a nationwide registry-based cohort study

OBJECTIVE

To assess academic performance in singletons aged 15-16 years conceived after frozen embryo transfer (FET) compared with singletons born after fresh embryo transfer (ET) in Danish cohorts born from 1995 to 2001.

DESIGN

Danish national registry-based cohort study.

SETTING

Danish national registries.

POPULATION

All 6495 singletons conceived after assisted reproductive technology (ART) treatment in Denmark from 1995 to 2001 [FET (n) = 423; fresh ET (n) = 6072].

METHODS

Mean test scores on a national standardised and international comparable grading-scale. Comparisons of test score were first made in univariate analysis (Model 1) and secondly in a multivariate linear model (Model 2) adjusting for relevant reproductive and socio-demographic covariates such as the occupational and educational level of the parents. Sensitivity analyses on FET-IVF (in vitro fertilisation) versus fresh ET-IVF and FET-ICSI (intracytoplasmic sperm injection) versus fresh ET-ICSI were made. Linear mixed models were used to account for the correlation in test scores of siblings for continuous outcome.

MAIN OUTCOME MEASURES

Mean overall test score and test score in Danish, mathematics, English, and physics/chemistry.

RESULTS

Crude and adjusted mean test scores were similar for adolescents conceived after FET compared with fresh ET. The crude mean difference was +0.11 (95% CI -0.11; 0.34), and the adjusted mean difference was +0.12 (95% CI -0.09; 0.34).

CONCLUSIONS

Adolescents conceived after FET had similar academic performance at 15-16 of years of age compared with children conceived after fresh ET.

TWEETABLE ABSTRACT

Using frozen embryos in fertility treatment does not affect school performance in Danish adolescents aged 15-16 years.

No effect of IVF culture medium on cognitive development of 9-year-old children

STUDY QUESTION

Do embryo culture media used during an IVF/ICSI treatment have an effect on cognitive development of singleton IVF children at 9 years of age?

SUMMARY ANSWER

Cognitive development of children born after culture in two different embryo culture media is comparable.

WHAT IS KNOWN ALREADY

Previously, we have shown that the culture medium used in an IVF/ICSI treatment affects birthweight and weight at 2 years of age after alternating assignment to embryo culture in either K-SCICM (Cook) or G1™ Version 3 (Vitrolife). Children with low birthweight are known to have an increased risk for learning disabilities. Data on cognitive development in general of children born after ART are still conflicting, and the only study reporting on the effects of culture medium on cognitive development shows significant differences in cognitive development between two culture medium groups.

STUDY DESIGN SIZE DURATION

In this observational cohort follow-up study (MEDIUM-KIDS), parents of all singletons from our abovementioned study were approached after the ninth birthday of their child to participate in an additional follow-up study. Of the 294 eligible children included in the original study, 119 children (70 Vitrolife and 49 Cook) participated in the current study.

PARTICIPANTS/MATERIALS SETTING METHODS

All follow-up measurements were performed between March 2014 and December 2016. CITO (Dutch Central Institute for Test Development) developed the Dutch pupil monitoring system, which involves nationwide independent, standardized, academic achievement score tests to monitor the child's school performance twice a year at fixed time points from third grade onward. The tests include language skills (vocabulary and orthography), mathematics and reading capability and comprehension. Results from the tests performed between third and sixth grades, expressed as ability scores, were obtained from the school. To investigate school performance development over the years, we used a mixed effects multilevel model. The least complex model with the best fit was selected to analyze whether culture medium affects cognitive development in our cohort. The study had enough power to detect a difference in ability score that reflects at least one performance category between the two groups.

MAIN RESULTS AND THE ROLE OF CHANCE

No differences were seen in baseline characteristics between participants and non-participants (both parental and children characteristics). For all domains, the random intercept model was used. All analyses showed comparable results for the two culture medium groups. No significant differences were observed for any of the cognitive development domains, even after correction for potential confounders. Parental level of education was higher in the IVF group (45%) if compared to the national average level of education (35%), which most likely explains the higher CITO scores for the IVF children if compared to the National ability scores.

LIMITATIONS REASONS FOR CAUTION

A limitation of the study was its pseudo-randomized design and the relatively low participation rate of 40.5%. This and the number of missing data prevent us from drawing robust causal conclusions. However, as this is the first and therewith oldest cohort of children where culture medium was allocated alternatingly and used in a blinded setting, in the same period, with all other conditions identical this study gives up until now the best available evidence.

WIDER IMPLICATIONS OF THE FINDINGS

Our study analyzes the effects of culture medium on school performance of children born after IVF/ICSI in a prospective cohort study. Although further research on long-term academic skills and also on behavior is essential, our results are reassuring and should make parents of children born after IVF/ICSI feel comfortable with their children's cognitive development.

STUDY FUNDING/COMPETING INTERESTS

The study was financially supported by the March of Dimes (Grant no. #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NTR4220.

Cognitive development in children up to age 11 years born after ART-a longitudinal cohort study

STUDY QUESTION

How does the cognitive development of children conceived after ART (IVF and ICSI) - measured as cognitive skills at age 3, 5, 7 and 11 years - differ over time from those born after natural conception (NC)?

SUMMARY ANSWER

Improved measures of cognitive development up to age 5 years were recorded in children conceived with ART compared to NC, which attenuates by 11 years, with ART children still scoring slightly better than NC children.

WHAT IS KNOWN ALREADY

Results on the cognitive outcomes of children conceived after ART have been highly contradictory. Some have shown that ART children have an impaired behavioural, socio-emotional and cognitive development and higher risk of mental disorders. Others have reported no increased risk or difference. Cognitive development has not been previously examined using latent growth curve models from ages 3 to 11 years, also including appropriate attention to confounding parental characteristics.

STUDY DESIGN, SIZE, DURATION

Longitudinal data for the first five waves (2000-2012) of the UK Millennium Cohort Study were used, which is a two-stage sample of all infants born in 2000-2001 and resident in the UK at 9 months of age, drawn from the Department of Social Security Child Benefit Registers. A final sample of N = 15 218 children (125 IVF and 61 ICSI), from 14 816 families was used. Information was available for all waves for 8298 children. Four additional follow-up surveys were conducted in 2003, 2005, 2007 and 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our sample includes children born within a union (married or cohabiting parents) and where information on cognitive scores was available for at least two measurement points. Cognitive development was assessed with the British Ability Scales. At age 3 and 5 years (wave 2 and 3), children completed the naming vocabulary component, which measures expressive verbal ability. At age 7 years (wave 4), verbal cognitive abilities were assessed through the word reading test, and at age 11 years (wave 5) through a verbal similarity test. Two-tailed Student's t-tests examined differences between ART and NC groups. Growth curve models (random-coefficient, latent trajectory models) were used to study the effect of ART, confounding parental characteristics and health outcomes at birth, both at a baseline level of cognitive ability at age 3 years and on its growth rate.

MAIN RESULTS AND THE ROLE OF CHANCE

At age 3 and 5 years, children conceived with the aid of ART have higher verbal cognitive abilities than NC children (P < 0.001) but this consistently decreases over time and diminishes by age 11 years. Parental environment and resources are pivotal in children's cognitive development.

LIMITATIONS, REASON FOR CAUTION

The sample size of the ART cohort of children is small across each time period (N = 150-180) in comparison with NC children (N = 10 496-11 955). Owing to a limited sample size, we are also unable to compare IVF versus ICSI treatment.

WIDER IMPLICATIONS OF THE FINDINGS

With the increasing use of IVF and ICSI, these results indicate that there are no detrimental effects on children's early cognitive outcomes up to age 11 years, and highlight the importance of parental characteristics.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for this project was provided by the European Union's Seventh Framework Program (FP7 2007-2013) (No. 320116 Families and Societies), ESRC/NCRM SOCGEN Grant (ES/N0011856/1) and the SOCIOGENOME ERC Consolidator Grant (ERC-2013-CoG-615603) (to M.C.M.). The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.