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.

Adolescent attachment to parents and peers in singletons and twins born with assisted and natural conception

STUDY QUESTION

Does adolescent attachment to parents and peers differ between singletons and twins born with ART or natural conception (NC)?

SUMMARY ANSWER

Adolescent attachment anxiety with the father was higher among NC singletons than among ART and NC twins, whereas attachment avoidance with the father was higher in ART singletons than in NC singletons and NC twins. No differences were found in attachment to the mother, best friend or romantic partner.

WHAT IS KNOWN ALREADY

Most studies have not found differences between ART and NC singletons in parent–adolescent relationships, but twin relationships may be more at risk. No previous study has examined all four groups in the same study, or specifically looked at attachment relationships.

STUDY DESIGN, SIZE, DURATION

This was an 18-year, prospective and controlled longitudinal study with families of 496 ART singletons, 101 ART twin pairs, 476 NC singletons and 22 NC twin pairs. Families were recruited during the second trimester of pregnancy; the ART group was recruited from five infertility clinics in Finland and the control group was recruited from a hospital outpatient clinic during a routine visit.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mothers and fathers gave background information for this study during pregnancy, and during the child’s first year and early school age (7–8 years). For the ART group, infertility characteristics and prenatal medical information was also obtained from the patient registry of the infertility clinics. Children (originally 50% girls) filled in electronic questionnaires related to their attachment to mother, father, best friend and romantic partner (Experiences in Close Relationships—Relationship Structures) at 17–19 years of age.

MAIN RESULTS AND THE ROLE OF CHANCE

Adolescent attachment anxiety to father was higher in NC singletons than in ART twins, P = 0.004 and marginally higher than in NC twins, P = 0.06. Adolescent attachment avoidance to father was higher in ART singletons than in NC singletons, P = 0.006 and marginally higher than in NC twins, P = 0.055.

LIMITATIONS, REASONS FOR CAUTION

The sample size was small especially in the NC twin group and there was drop-out over the 18-year time period, especially among boys and families with lower parental education level. The study only included native Finnish-speaking families. The results could differ in a more diverse population. ART singletons were younger and had fewer siblings than ART twins and NC children, and ART and NC twins had more newborn health risks than ART and NC singletons.

WIDER IMPLICATIONS OF THE FINDINGS

The study adds to a growing body of evidence that neither ART treatments nor being a twin places mother–child relationships or peer relationships at long-term risk. However, in our study, which was the first to examine both ART and twinhood simultaneously, we found that there may be more problems in father–adolescent relationships, but only in ART singletons and only related to attachment avoidance. Our findings suggest that men, as well as women, should receive enough support in pre- and peri-natal health care during and after infertility treatments.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Academy of Finland (grant number 2501308988), the Juho Vainio Foundation and the Finnish Cultural Foundation. The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

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

Fertility Problems and Parenting Daily Hassles in Childhood: A 7-year Longitudinal Study of Adoptive Parents

Fertility problems are known to exert a negative impact on psychological health. Meanwhile, individuals with fertility challenges often view adoption as a positive healing experience. Yet, a dearth of work has examined the long-term impact that fertility problems have on adoptive parents and their childrearing stress. Here, we investigated how fertility problems related to parenting daily hassle (PDH) trajectories among adoptive mothers and fathers in the Early Growth and Development Study (N = 333). When adopted children were 9 months old, adoptive parents reported whether they had fertility problems prior to their decision to adopt and rated their PDH frequency and intensity on six occasions over the next 7 years. Multilevel models revealed inverse U-shaped curves for PDH among both fertile and infertile parents, such that PDH increased from child age 9 months until about 5 to 6 years and decreased thereafter. Mothers with fertility problems exhibited a steeper PDH incline from 9 months to the peak at child age 5 to 6, but also incurred a swifter subsequent decline. There were no significant differences in fathers' PDH trajectories based on fertility problems. We discuss why fertility problems appear to impact PDH trajectories for mothers rather than fathers.

Conversation Orientation Moderates the Relationship between Information Sharing of Medically Assisted Reproduction and Child Adjustment

Parents who experienced infertility have increasingly used medically assisted reproduction (MAR) to add children to their families over the past few decades. These parents will need to decide if they will tell their children about being conceived using MAR. Although MAR information sharing operates within family contexts, little is known about the role of conversation orientation-one family contextual factor-in child outcomes associated with MAR information sharing in middle childhood. Derived from the Family Communication Patterns Theory, this study proposes that conversation orientation moderates the associations between MAR information sharing and children's psychosocial adjustment. This proposal was tested using a sample of 81 6- to 12-year-old MAR-conceived children from 55 families and a structured observational measure of conversation orientation. Multiple regression analyses showed that MAR information sharing interacted with conversation orientation to influence children's behavioral and attention problems but not emotional problems. In families with high conversation orientation, MAR information sharing was not significantly associated with children's behavioral and attention problems. In families with low conversation orientation, MAR information sharing was significantly associated with an increase in children's behavioral and attention problems. Results of this exploratory study demonstrate the potential significance of general communication orientation in understanding child outcomes of MAR information sharing and highlight the needed family context nuances in MAR research.

The psychosocial health of children born after medically assisted reproduction: Evidence from the UK Millennium Cohort Study

The increasing number of children conceived through medically assisted reproduction (MAR, including IVF/ICSI, intrauterine insemination and ovulation induction) has led to concerns about the potential negative effects of fertility treatments on children’s psychosocial health. Some studies suggest that MAR children might be at higher risk of developing psychosocial problems when they enter adolescence. However, very few studies have examined the development of MAR children after childhood. Moreover, even though parental socio-economic characteristics are known to be highly correlated with children’s psychosocial development, most existing studies on the outcomes of MAR children did not take into account the selective characteristics of the couples who accessed fertility treatments. Using data from waves 1–6 of the UK Millennium Cohort Study, we compare the psychosocial health, as measured by the Strengths and Difficulties Questionnaire, of MAR children to that of naturally-conceived (NC) children, up to and including the age of 14. We control for a wide range of time-constant child and parental characteristics that might confound the association between MAR and the psychosocial health of children. Results from multilevel random intercept models that do not account for parental characteristics show that MAR children have a lower incidence of psychosocial problems than NC children. In models that control for parental characteristics, MAR children are found to have a higher incidence of psychosocial problems than NC children at age three, which suggests that high parental resource levels both explain the advantage of MAR children in unadjusted models, and mask the potentially adverse effects of MAR at young ages. However, in the fully adjusted models in which MAR children have more psychosocial problems at young age, the differences with respect to NC children decrease with age and become statistically and substantively negligible by end of follow-up at age 14. This result suggests that the use of MAR does not increase children’s risk of having psychosocial problems at the onset of adolescence.

•

We compare Medically Assisted Reproduction (MAR) and naturally conceived children.

•

MAR children experience lower levels of psychosocial problems than NC children at all ages from 3 to 14.

•

The selective characteristics of MAR parents explain the observed difference.

•

Net of parental characteristics, young MAR children have higher levels of psychosocial problems, but the gap decrease and eventually converges by age 14.

Experiences and outcomes of organ-sparing surgery for testicular tumour with benign tendency

INTRODUCTION

We retrospectively investigated and summarized our experiences and the outcomes of organ-sparing surgery (OSS) for testicular tumour with benign tendency.

METHODS

From April 2000 to March 2012, 11 selected patients with testicular tumour underwent OSS. Preoperative and postoperative organ functional and oncologic indexes were analyzed and compared.

RESULTS

All operations were completed without conversion to radical orchiectomy. Intraoperative frozen section and routine postoperative pathology showed tumours with benign tendency. The normal appearance of the scrotum and functional integrity of the testis were preserved. Preoperative and postoperative serum sex hormone levels, international index of erectile function (IIEF-5) scores, and semen quality were not significantly different. Tumour recurrence or metastasis did not occur during follow-up.

CONCLUSIONS

Our results showed the feasibility and safety of OSS to treat testicular tumour with benign tendency. With careful selection and rigorous follow-up, some testis tumor can be treated with OSS to maximally maintain normal appearance and function of the testis. The retrospective single-centre study and small sample size are main limitations. More evidence is needed to establish the large-scale application of OSS.

First childbirth and motherhood at post natural fertile age: a persistent and intergenerational experience of personal and social anomaly?

This study was aimed at understanding long-term psychosocial implications of first childbirth at post natural fertile age following assisted reproductive treatment. Twenty women, whose average age at childbirth was 45, participated. Findings show that the sense of anomaly experienced prior to pregnancy and childbirth related to infertility and advanced age continued during treatment, pregnancy, and motherhood. Participants associated their advanced age as cause for what they perceived as a similar sense of anomaly experienced by their children. The issue of a continuing and intergenerational sense of anomaly should be addressed when counseling women considering fertility treatment at advanced age.

Psychological adjustment in adolescents conceived by assisted reproduction techniques: a systematic review

BACKGROUND

Adolescence is a transitional time for identity formation and relationships with parents. While people born through assisted reproduction techniques (ART) appear to be well adjusted in childhood, it is unclear whether these findings carry into adolescence, and whether diverse ART have different psychological outcomes. This review summarizes what is known about the psychological adjustment and family relationships of the growing number of children born through ART who are reaching adolescence.

METHODS

The Pubmed, Web of Knowledge, PsycINFO and Scopus databases were searched systematically for peer reviewed papers focusing on adolescent psychological adjustment and parent-adolescent relationships in families created by ART. Key search inclusion criteria included all papers published in English relating to adolescents aged between 11 and 18 years.

RESULTS

Seventeen publications with varied methodologies were identified by this review. Only papers relating to in vitro fertilization (IVF), egg donation and donor insemination were identified. Results were categorized according to ART that used the parents' own gametes (IVF) and those that involved reproductive donation (egg donation, and donor insemination). Compared with naturally conceived adolescents and standardized normative samples, adolescents born through all ARTs seemed to be equally well adjusted, and to have positive parent-adolescent relationships. Some differences were however identified based on the type of ART used. In particular, the sex of the parent and child, along with age and process of disclosure of the adolescent's conception were identified as key mediators of parent-adolescent relationships in families created by donor insemination.

CONCLUSIONS

The studies in this review indicate that children born through ART have positive parent-adolescent relationships and are well adjusted, with some slight differences based on different ART. The generalizability of findings may be limited by the general low level of disclosure to adolescents in some of the publications, the small sample sizes of studies in the field, along with the large age range that encompasses adolescence. Findings should also be interpreted in light of the fact that many publications focus on singleton births. Future studies should also focus on egg donation, surrogacy and embryo donation, as well as the disclosure processes, and adolescents born into non-traditional families (same-sex or single parents) or those born using different types of donor (anonymous, identity-release or known).

An overview of studies on psychological well-being in children born following assisted reproductive technologies

Over the course of the past 35 years, assisted reproductive technologies (ARTs) have been increasingly used worldwide, while debates on their safety have been generated. Birth defects and imprinting disorders were reported in previous research. Thus, the psychological development of children born following ARTs has become a major concern nowadays. This review gives a systematic view of psychological well-being of children conceived by different types of ART, including in vitro fertilization, intracytoplasmic sperm injection (ICSI), preimplantation genetic diagnosis/screening, and in vitro maturation. The previous studies are analyzed in three sections: (1) cognitive, motor, and language developments, (2) behavior problems and socio-emotional development, and (3) parent-child relationship. We conclude that although the majority of the studies on cognitive, motor, and language developments reported comparable achievements in the ART group vs. the naturally conceived group, lower intelligence quotient (IQ) scores, worse visual-motor ability or locomotor development, and delayed receptive language competence were found in the ART group. The results on the socio-emotional development were reassuring. As for the behavior problems, a higher prevalence of behavior problems existed in ART children; moreover, ICSI children were found to be at a higher risk of autism than the general population. Meanwhile, ART parents tended to have positive parental attitudes and be more protective of their children. Some suggestions for further research are also given in this review.

Comparing indicators of health and development of singleton young adults conceived with and without assisted reproductive technology

OBJECTIVE

To compare outcomes for young adults conceived by assisted reproductive technology (ART) with non-ART-conceived young adults.

DESIGN

Cohort study.

SETTING

Not applicable.

PARTICIPANT(S)

Mothers and their offspring (aged 18-28 years) conceived by ART; mothers and their non-ART-conceived offspring, randomly selected from the same source population.

INTERVENTION(S)

Structured telephone interviews, one with mothers and another with their young adult offspring.

MAIN OUTCOME MEASURE(S)

Maternal report on young adult offspring hospitalizations and chronic illness accumulated over the first 18 years of their lives; young adult self-report on perceived current quality of life, body mass index, pubertal development, and educational achievement.

RESULT(S)

Of 1,480 eligible ART mothers, 80% were traced and contacted. Of those, 656 (55%) participated, reporting on 705 ART-conceived offspring; 269 (23%) declined participation and 262 (22%) did not respond. Of the participants, 84% consented to contact with their young adult offspring, of whom 547 (92%) participated. Random-digit dialing recruited 868 non-ART mothers and 549 offspring. Compared with non-ART young adults, the ART group had significant increases in three maternally reported outcomes: 1) hospital admissions, including those in the secondary school years; 2) atopic respiratory conditions; and 3) combined endocrine, nutritional, and metabolic disease ICD-10 category. Young adult reported outcomes were similar for both groups.

CONCLUSION(S)

This study addresses gaps in knowledge of outcomes beyond adolescence for those conceived by ART. Results show few adverse outcomes in this large cohort of young adults, but additional assessment through clinical review is required to address issues unable to be examined in this study.

Assisted reproduction and child neurodevelopmental outcomes: a systematic review

OBJECTIVE

To systematically review the existing literature on neurodevelopmental outcomes in children born after medically assisted reproduction compared with those of children born after spontaneous conception.

DESIGN

Systematic review.

SETTING

Not applicable.

PATIENT(S)

Children born after medically assisted reproduction vs. reference groups of spontaneously conceived children.

INTERVENTION(S)

Data were reviewed from worldwide published articles, without restrictions as to publication year or language. A total of 80 studies included between 31 and 2,446,044 children.

MAIN OUTCOME MEASURE(S)

Child neurodevelopmental outcomes categorized as cognitive, behavioral, emotional or psychomotor development, or diagnoses of mental disorders.

RESULT(S)

For infants, studies on psychomotor development showed no deficits, but few investigated cognitive or behavioral development. Studies on toddlers generally reported normal cognitive, behavioral, socio-emotional, and psychomotor development. For children in middle childhood, development seems comparable in children born after assisted reproduction and controls, although fewer studies have been conducted with follow-up to this age. Very few studies have assessed neurodevelopmental outcomes among teens, and the results are inconclusive. Studies investigating the risk of diagnoses of mental disorders are generally large, with long follow-up, but the results are inconsistent.

CONCLUSION(S)

It may tentatively be concluded that the neurodevelopment of children born after fertility treatment is overall comparable to that in children born after spontaneous conception.

Effects of pregnancy planning, fertility, and assisted reproductive treatment on child behavioral problems at 5 and 7 years: evidence from the Millennium Cohort Study

OBJECTIVE

To examine the effects of pregnancy planning, time to conception (TTC), and assisted reproductive technologies (ART) on child behavior.

DESIGN

Prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 12,380 singletons recruited at 9 months and followed-up at 5 and 7 years. Conceptions were divided into "unplanned" (unplanned, unhappy), "mistimed" (unplanned, happy), "planned" (planned, TTC <12 months), "subfertile" (planned, TTC ≥ 12 months), "ovulation induced" (received clomiphene citrate), and "ART" (IVF or intracytoplasmic sperm injection).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Child behavior (Strengths and Difficulties Questionnaire [SDQ]).

RESULT(S)

Mistimed and unplanned children had higher average SDQ scores at age 5 and 7 years and were significantly more likely to have a clinically relevant behavioral problem compared with the planned group. The ART children had significantly higher average SDQ scores at both 5 and 7 years compared with the planned group. An increase in clinically relevant behavioral problems was observed at 5 years (odds ratio 2.05 [95% confidence interval 0.96, 4.42]) but failed to reach statistical significance. No effects were observed in the subfertile and ovulation-induced groups.

CONCLUSION(S)

Unplanned and mistimed children exhibit more behavioral problems than their planned peers. Though ART children have higher mean total difficulties scores, this did not translate into a statistically significant increase in clinically relevant behavioral problems.

An international view of surgically assisted conception and surrogacy tourism

Modern medicine, specifically assisted reproductive technology (ART), has overtaken the law in many jurisdictions around the world. New technologies and practices open a Pandora's Box of ethical, religious, social and legal questions, and may present a variety of significant legal problems to the courts and legislators. Surrogate motherhood and pregnancy through ART have both attracted controversy. Some groups condemn ART and want it banned while its supporters acknowledge there is a need for legislative guidelines and regulations. A proposed statute, the Assisted Reproductive Technique Services Act, aimed at regulating reproductive technologies, including surrogacy arrangements, will be introduced in the Malaysian parliament, probably in 2012, and the Assisted Reproductive Technology (Regulation) Bill 2010 is already before the Indian parliament. This paper will discuss several of the potential socio-legal issues surrounding ART in the light of the complex situation, with a comparative analysis of the Malaysian, USA, UK and Indian positions.

Childhood outcomes of assisted reproductive technology

There is a large population of children conceived via assisted reproductive technology (ART), which continues to increase worldwide, without a clear understanding of associated long-term outcomes. ART children are more likely to be the result of multiple pregnancies, and thus to be born prematurely or low birthweight. There is growing evidence that ART children are phenotypically and biochemically different from naturally conceived children, but the mechanism(s) leading to these changes have not been elucidated. There is a possible increased risk of rare imprinted gene disorders in these children. However, it remains unclear whether more subtle changes in DNA methylation occur commonly, leading to differences in gene expression and phenotype in ART children. Although an increased risk of cancer among ART children has been reported, the role of ART in the development of cancer has not been demonstrated. Further research and ongoing surveillance of ART children is essential to better understand the possible effects of ART on the long-term health of this population.