Outcome in children from cryopreserved embryos

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.

Health of 2-year-old children born after vitrified oocyte donation in comparison with peers born after fresh oocyte donation

STUDY QUESTION

Does oocyte vitrification adversely affect the health of 2-year-old children compared with peers born after use of fresh oocytes in a donation programme?

SUMMARY ANSWER

The growth and health of 2-year-old children born after oocyte vitrification are similar to those of peers born after use of fresh oocytes.

WHAT IS KNOWN ALREADY

Although oocyte vitrification is a well-established procedure in ART, the evidence on its safety for offspring is limited. Currently, no disadvantageous effects of oocyte vitrification have been shown in terms of obstetric and neonatal outcome. However, no data beyond the neonatal period are available to date.

STUDY DESIGN, SIZE, DURATION

A combined retrospective and prospective observational study was performed in a tertiary reproductive centre. The retrospective data were available in our extensive database of children born after ART. Donor cycles with an oocyte retrieval between January 2010 and March 2017 and a fresh embryo transfer resulting in the livebirth of a singleton were selected from the established oocyte donation programme. Fresh or vitrified oocytes were used in the donor cycles and all pregnancies in oocyte recipients were achieved after ICSI. Only children residing in Belgium were eligible for follow-up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Biometric and health parameters of 72 children born after oocyte vitrification were compared with those of 41 children born after use of a fresh oocyte. Data were collected by means of questionnaires and physical examinations at the age of 21–30 months. The primary outcome measures were anthropometry and health at 2 years of age.

MAIN RESULTS AND THE ROLE OF CHANCE

Length, weight, BMI, head circumference, left arm circumference and waist circumference at the age of 2 years were comparable between the vitrification and fresh group, also after adjustment for treatment, and maternal and neonatal characteristics (all P > 0.05). Health of the children in terms of hospital admission and surgical intervention rates were comparable between the vitrification and fresh group (both P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

Although the current study is the largest series describing health parameters beyond the neonatal period, the small numbers still preclude definite conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

This study provides the first evidence indicating that oocyte vitrification does not adversely affect the growth and health of offspring beyond the neonatal period.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts, all issued by the Vrije Universiteit Brussel. All co-authors declared no conflict of interest in relation to this work. Both the Centre for Reproductive Medicine and the Centre for Medical Genetics from the UZ Brussel have received several educational grants from IBSA, Ferring, MSD and Merck for either research on oocyte vitrification or for establishing the database for follow-up research and organizing the data collection.

Blood Flow in the Ears of Patients Receiving Cochlear Implants

We measured cochlear blood flow (CBF) in 55 patients who received cochlear implants, using a laser-Doppler probe placed over the site of drilling in the cochlear bony wall. The subjects included 29 patients with congenital deafness of unknown cause, 8 with idiopathic progressive sensorineural hearing loss, 4 with postmeningitic deafness, 3 with Waardenburg's syndrome, 3 with congenital cytomegalovirus infection, and 8 whose deafness had other causes. There was a wide range of CBF values in patients with congenital deafness of unknown cause. In the patients with idiopathic progressive sensorineural hearing loss, the CBF was significantly lower in patients more than 40 years old. Intracochlear calcification following meningitis appears to be associated with a reduced CBF.

Physical health of singleton children born after frozen embryo transfer using slow freezing: a 3-year follow-up study

STUDY QUESTION

Are there differences in the physical health of singleton children born after frozen embryo transfer (FET) compared with children born after fresh embryo transfer (fresh ET)?

SUMMARY ANSWER

Register-based health indicators were similar among FET and fresh ET singletons during a 3-year follow-up.

WHAT IS KNOWN ALREADY

Large cohort studies have shown that perinatal outcomes are similar or even better in FET than fresh ET children. The early childhood morbidity among FET and fresh ET children has been shown to be quite similar, but so far these studies have been small. The short-term health outcomes of assisted reproductive technology (ART) children have been shown to be slightly worse compared with spontaneously conceived children.

STUDY DESIGN, SIZE, DURATION

This register-based study includes women who had undergone ART treatments leading to singleton live births (n = 4758 children) in 1995-2006. A 10% random sample of women with spontaneous pregnancies from the Finnish Medical Birth Register (FMBR) served as the reference group (n = 31 137 children). The children were identified through the FMBR by using the mother's personal identification (ID) number. Children's ID numbers were linked with two nationwide registries; the Finnish Hospital Discharge Register and the Cause-of-Death Register at Statistics Finland. Information on all visits was received until 2009 using ICD-10 codes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study includes 1825 children born after FET, 2933 children born after fresh ET and 31 137 children born after spontaneous pregnancies. The risk estimates for diseases were adjusted for the child's year of birth and maternal age, parity, socio-economic status and prematurity. The study focused on the differences between FET and fresh ET children.

MAIN RESULTS AND THE ROLE OF CHANCE

Most health indicators were similar among FET and fresh ET children during the 3-year follow-up. The most common discharge diagnoses, including gastroenteritis and colitis, otitis, upper and lower respiratory diseases, asthma and allergies were similar between the ART groups. A large proportion of FET children (70.1%) and fresh ET children (69.9%) had visited a hospital at least once (P = 0.877). The risk of hospital admission did not differ between the two groups after adjusting for premature births [adjusted odds ratio (aOR) 1.01; 0.88-1.17]. Comparing with children born after spontaneously conceived pregnancies, the risk of hospital admission was slightly increased in the ART group, even after adjusting for premature births (aOR 1.10; 1.02-1.19).

LIMITATIONS, REASONS FOR CAUTION

Due to the study design, we were not able to control for some parental background factors, such as the cause and length of infertility. Furthermore, the health registries do not include data on the growth of the children. Our findings are generalizable only to the slow-freezing method.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides further evidence of the safety of embryo cryopreservation. The early physical health of FET children is similar to that of children born after fresh ET.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the University Hospital of Oulu and Helsinki, Finland. The National Institute for Health and Welfare (THL) covered the data linkages and the work of Mika Gissler. There are no competing interests to be reported.

I was born following ART: how will I get on at school?

With an ever-expanding population of children born after in-vitro fertilisation (IVF), the widespread use of assisted reproductive techniques (ART) has placed a great emphasis on the need to study their long-term outcomes. Indeed, there has been concern that mechanisms used in ART may have a detrimental effect on the neurocognitive development of these children. Reassuringly, most neurocognitive and motor development studies using various assessment scales have generally found no differences between intracytoplasmic sperm injection, IVF and naturally conceived children. Only a few studies have reported concerns. In terms of predictors of intelligence in children, ART appears to have a minimal effect in comparison to birth weight, gestational age, socio-economic status, and parental educational levels. Nevertheless, further research of higher methodological quality in children beyond pre-school age and on newer ART procedures is needed.

Obstetric and perinatal outcome of babies born from vitrified oocytes

OBJECTIVE

To assess outcomes after oocyte vitrification on obstetric and perinatal outcomes compared with those achieved with fresh oocytes.

DESIGN

Retrospective cohort study.

SETTING

Private university-affiliated IVF center.

PATIENT(S)

Children born after use of vitrified oocytes (1,027 from 804 pregnancies) and fresh oocytes (1,224 from 996 pregnancies). Singleton and multiples pregnancies from own and donated ova were included.

INTERVENTION(S)

Oocyte vitrification by the Cryotop method.

MAIN OUTCOME MEASURE(S)

Pregnancy, delivery, and neonatal outcomes.

RESULT(S)

Vitrification had no clinically relevant adverse effects on obstetric and perinatal outcomes after adjusting for potential confounders. No differences were found between the vitrified and fresh oocyte groups in the rate of obstetric problems (including diabetes, pregnancy-induced hypertension, preterm birth, anemia, and cholestasis), gestational age at delivery, birth weight, Apgar scores, birth defects, admission to neonatal intensive care unit (ICU), perinatal mortality, and puerperal problems. Only a greater number of invasive procedures (adjusted odds ratio 2.12; 95% confidence interval 1.41-3.20), and a reduced occurrence of urinary tract infection (adjusted odds ratio 0.51; 95% confidence interval 0.28-0.91), were observed in the vitrified oocytes group.

CONCLUSION(S)

Although our data, the largest series to date, suggest that oocyte vitrification does not increase adverse obstetric and perinatal outcomes in children conceived with vitrified oocytes, further studies with larger samples are required to reinforce our conclusions.

Health outcomes of children born after IVF/ICSI: a review of current expert opinion and literature

The Sixth Evian Annual Reproduction (EVAR) Workshop Group Meeting was held to evaluate the impact of IVF/intracytoplasmic sperm injection on the health of assisted-conception children. Epidemiologists, reproductive endocrinologists, embryologists and geneticists presented data from published literature and ongoing research on the incidence of genetic and epigenetic abnormalities and congenital malformations in assisted-conception versus naturally conceived children to reach a consensus on the reasons for potential differences in outcomes between these two groups. IVF-conceived children have lower birthweights and higher peripheral fat, blood pressure and fasting glucose concentrations than controls. Growth, development and cognitive function in assisted-conception children are similar to controls. The absolute risk of imprinting disorders after assisted reproduction is less than 1%. A direct link between assisted reproduction and health-related outcomes in assisted-conception children could not be established. Women undergoing assisted reproduction are often older, increasing the chances of obtaining abnormal gametes that may cause deviations in outcomes between assisted-conception and naturally conceived children. However, after taking into account these factors, it is not clear to what extent poorer outcomes are due to the assisted reproduction procedures themselves. Large-scale, multicentre, prospective epidemiological studies are needed to investigate this further and to confirm long-term health consequences in assisted-conception children. Assisted reproduction treatment is a general term used to describe methods of achieving pregnancy by artificial means and includes IVF and sperm implantation. The effect of assisted reproduction treatment on the health of children born using these artificial methods is not fully understood. In April 2011, fertility research experts met to give presentations based on research in this area and to look carefully at the evidence for the effects of assisted reproduction treatment on children's health. The purpose of this review was to reach an agreement on whether there are differences in the health of assisted-conception children with naturally conceived children. The researchers discovered no increased risk in birth defects in assisted-conception children compared with naturally conceived children. They found that IVF-conceived children have lower birth weights and higher fat under the skin, higher blood pressure and higher fasting glucose concentrations than naturally conceived children; however, growth, development and cognitive function are similar between groups. A very low risk of disorders of genetic control was observed in assisted-conception children. Overall, there did not appear to be a direct link between assisted reproduction treatment and children's health. The researchers concluded that the cause of some differences in the health of children conceived using assisted reproduction treatment may be due to the age of the woman receiving treatment. Large-scale, research studies are needed to study the long-term health of children conceived using assisted reproduction treatment.

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.

Opinions and practice patterns of obstetricians-gynecologists in the United States regarding amniocentesis in twins

OBJECTIVE

Accurate amniocentesis-related pregnancy loss (ARL) rates for twin gestations remains elusive because of varying ARL definitions in the literature. We examined how OB/GYNs define/counsel women carrying twins about ARL.

METHODS

A random sample of 1000 American College of OB/GYN (ACOG) fellows and ACOG Collaborative Ambulatory Research Network (CARN) members were mailed surveys about their opinions/practice patterns regarding amniocentesis in twins. There were 208/400 (52%) CARN members and 166/600 (27%) ACOG fellows who returned the survey (37% response rate).

RESULTS

Of respondents, 80.8% practiced general OB/GYN, and 9.1% practiced maternal fetal medicine. Of respondents, 72% discussed amniocentesis for prenatal diagnosis. Of these, 91.7% discuss the risk of ARL; however, 47.4% do not quote an ARL rate. Of those who discuss ARL rates, 65% quote a rate greater than for singletons. Regarding monochorionic-diamniotic twins, 12.1% of respondents said the ARL rate was less, 39.6% said equal to, and 38.9% said greater than for dichorionic twins. Table 1 lists the most common clinical definitions/time intervals used to describe ARL.

CONCLUSION

Various definitions/ARL rates are used when counseling about ARL in twins. Further studies using a widely accepted definition of ARL are necessary to improve the counseling of women considering amniocentesis for prenatal diagnosis in twins.

Chromosome abnormalities and viability of vitrified eight-cell mouse embryos at presence of two different cryoprotectants at different storage durations

OBJECTIVE

Experiments were conducted to find the differences between post-thaw viability and chromosome aberrations in eight-cell mouse embryos at presence of dimethyl sulfoxide (DMSO) and 1, 2-propanediol (PROH) as croprotectants in different storage durations.

MATERIALS AND METHODS

In this case-control study, a total number of 720 mouse embryos from about 250 NMRI mice were vitrified with 30% PROH or DMSO; each diluted with a solution containing 30% ficol plus 0.5 M sucrose. Embryos were exposed to the solutions for 0.5 minute at 25℃ followed by cooling in liquid nitrogen, then after appropriate storage duration, they were rapidly warmed. Besides, there were 100 mouse embryos for each cryoprotectant group (totally 200 embryos) as control. Embryo survival was assessed by in vitro development, and chromosome abnormalities were analyzed by Giemsa staining.

RESULTS

The proportion of mitotic abnormalities in PROH/DMSO vitrified embryos was significantly higher than unfrozen control group. This was confirmed also by a reduced viability of the embryos as judged by a culture at the blastocyst stage (p<0.05 in all test groups).

CONCLUSION

It can be deduced that long term cryopreservation may result in chromosomal abnormalities and/or low viability.

In vitro fertilization (IVF): a review of 3 decades of clinical innovation and technological advancement

In vitro fertilization, popularly referred to as IVF, has captured the attention of the public since its sensational introduction in 1978. Today assisted reproductive technology is available throughout most of the civilized world, and the practice is largely different from that used during the early days. Refinements in laboratory technology and clinical practice have allowed IVF to evolve into a medical procedure that is efficient, safe, readily accessible, and relatively affordable. More than 2 million IVF children have been born to date, and it is likely that continued enhancements will widen its appeal and applicability.

Comparison of early pregnancy and neonatal outcomes after frozen and fresh embryo transfer in ART cycles

PURPOSE

frozen embryo transfer (FET) has no clear negative impact on neonatal outcome compared with fresh embryo transfer (ET) and appears to result in similar or even better neonatal outcome. The objective of this study was to compare early pregnancy outcome and neonatal health of children born after FET and fresh ET.

METHODS

in this study early pregnancy and neonatal outcomes after FET (n = 200) and fresh ET (n = 500) were compared.

RESULTS

for early pregnancy, biochemical pregnancy was comparable between FET and fresh ET groups. Spontaneous abortion was significantly higher in FET (14.5%) than fresh ET group (9%). Neonatal outcome was comparable between both groups except for lower live birth rate in FET (55%) versus fresh ET group (66%).

CONCLUSION

FET has similar neonatal outcome in terms of prematurity, low birth weight, stillbirth, neonatal death and major malformation compared with fresh ET.

Infant outcome of 957 singletons born after frozen embryo replacement: the Danish National Cohort Study 1995-2006

OBJECTIVE

To examine infant outcome of singletons born after cryopreservation of embryos (Cryo).

DESIGN

National population-based controlled follow-up study.

SETTING

Denmark, 1995-2007.

PATIENT(S)

The study population was 957 Cryo singletons (Cryo-IVF, n=660; Cryo-ICSI, n=244; Cryo-IVF/-ICSI, n=53). The first control group was all singletons born after fresh IVF or intracytoplasmic sperm injection (ICSI) during the same period (IVF, n=6904; ICSI, n=3425). The second control group comprised a random sample of non-assisted reproductive technology (ART) singletons (n=4800).

INTERVENTION(S)

All observations were obtained from national registers.

MAIN OUTCOME MEASURE(S)

Low birth weight (LBW; <2500 g), preterm birth (PTB; <37 weeks), congenital malformations, mortality, and morbidity.

RESULT(S)

Birth weight was higher in Cryo (mean=3578 g, SD=625) versus fresh (mean=3373 g, SD=648) and in Cryo versus non-ART (mean=3537 g, SD=572), and this was also the case for first birth only. Lower adjusted risk of LBW (odds ratio [OR]=0.63; 95% confidence interval [CI], 0.45-0.87) and PTB (OR=0.70; 95% CI, 0.53-0.92) was observed in Cryo versus fresh. Similar LBW and PTB rates were observed when comparing Cryo with non-ART, but the perinatal mortality rate was doubled in Cryo (1.6%) compared with non-ART (0.8%) singletons, and the adjusted risks of very preterm birth (<34 weeks) and neonatal admittance were also significantly increased. No significant differences in the prevalence rates of birth defects, neurological sequelae, malignancies, and imprinting-related diseases were observed between the Cryo and the two control groups. However higher malformation and cerebral palsy rates were observed in the total Fresh vs. non-ART group.

CONCLUSION(S)

Cryo singletons have better neonatal outcome than offspring after fresh ET but poorer compared with non-ART singletons.

Neonatal outcome of 937 children born after transfer of cryopreserved embryos obtained by ICSI and IVF and comparison with outcome data of fresh ICSI and IVF cycles

BACKGROUND

To evaluate the safety of cryopreservation in combination with IVF and ICSI, prenatal diagnosis and neonatal outcome were investigated in children conceived from frozen-thawed ICSI embryos (cryo ICSI) and frozen-thawed IVF embryos (cryo IVF). Data were also compared with earlier published results from fresh ICSI and IVF embryos.

METHODS

Questionnaire data and results of physical examination at 2 months of 547 cryo ICSI children and 390 cryo IVF children were compared, and these were also compared with those of infants born after transfer of fresh embryos.

RESULTS

Birth characteristics were comparable for cryo ICSI and cryo IVF infants. Cryo singletons showed a trend towards higher mean birthweight compared with fresh singletons, in ICSI and IVF, reaching significance when all cryo (ICSI plus IVF) singletons were considered. Low birthweight rate according to multiplicity was comparable between the fresh and the cryo groups, in ICSI and IVF. Non-statistically significantly increased rates of de novo chromosomal anomalies (3.2%) were found in cryo ICSI fetuses/children compared with the fresh ICSI group (1.7%) (OR 1.96; 95% CI 0.92-4.14). Major malformations were more frequently observed in cryo ICSI live borns (6.4%) than in cryo IVF live borns (3.1%) (OR 2.15; 95% CI 1.10-4.20) and fresh ICSI live borns (3.4%) (OR 1.96; 95% CI 1.31-2.91).

CONCLUSIONS

In cryo ICSI compared with cryo IVF, prenatal and neonatal outcome results were comparable, except for a higher major malformation rate in the cryo ICSI group. In the total cryo group compared with the total fresh group, we found a higher mean birthweight in singletons and a higher major malformation rate in live borns.

An overview of studies on early development, cognition, and psychosocial well-being in children born after in vitro fertilization

OBJECTIVE

To examine whether sufficient research has been done and definite conclusions can be drawn on the psychological outcome of children born after in vitro fertilization (IVF), a review was performed of studies on early development, cognition, and psychosocial well-being in IVF children.

METHOD

PubMed and PsycINFO databases were searched. All English language studies up to 2006 addressing these topics were included.

RESULTS

After 25 years of follow-up studies on the development, school outcome, and psychosocial well-being of IVF children, it seems that mental and psychomotor development during the first year and preschool years and cognitive development at 5 years are not deviant. At 6-12 years of age, no differences were observed in cognitive and school performance compared with naturally conceived children; however, the number of studies in this age group is limited. No studies are available that evaluate cognitive aspects and school performance at secondary school age. Overall, positive parent-child relationships were reported in IVF families. In some studies, IVF mothers report more difficulties with their child's behavior only in the child's first year. With regard to the children's psychosocial well-being, no differences were found up to the age of 8 years. Although after that age, slight indications for some socioemotional and behavioral problems emerged, a large study on the onset of puberty reported that psychosocial functioning was reassuring. Data for adolescents are still lacking.

CONCLUSION

Psychological functioning of those born after IVF is reassuring. However, follow-up should be continued and studies should focus on specific cognitive abilities, school performance, and emotional functioning in adolescence.

A survey of assisted reproductive technology births and imprinting disorders

BACKGROUND

Genomic imprinting is an epigenetic process in which allele-specific gene expression is dependent on the parental inheritance. Although only a minority of human genes are imprinted, those that have been identified to date have been preferentially implicated in prenatal growth and neurodevelopment. Mutations or epimutations in imprinted genes or imprinting control centres are associated with imprinting disorders such as Angelman syndrome (AS) and Beckwith-Wiedemann syndrome (BWS). Recently, an increased frequency of assisted reproductive technology (ART) conceptions has been reported in children with BWS and AS. However, the risk of imprinting disorders in ART children is unknown.

METHODS

We undertook a survey of 2492 children born after ART in the Republic of Ireland and Central England with the aim of detecting cases (both clinically diagnosed and previously unrecognized) of BWS and AS in this cohort. The response rate to an initial questionnaire was 61%, corresponding to data for 1524 children. After evaluation of the questionnaire, 70 children were invited for a detailed clinical assessment, and 47 accepted (response rate of 67%).

RESULTS

In this entire cohort, we detected one case of BWS and no cases of AS. We did not find evidence that there exists a significant group of ART children with unrecognized milder forms of AS or BWS.

CONCLUSIONS

Although previous studies have suggested an increased relative risk of BWS and AS after ART, our findings suggest that the absolute risk of imprinting disorders in children conceived by ART is small (<1%). Precise risk estimates of risk are difficult to define because of the rarity of the conditions and incomplete response rates to the questionnaire and clinical examination invitations. Hence further investigations are indicated to (i) refine the absolute and relative risks of imprinting disorders after ART and (ii) ensure that changes in ART protocols are not associated with increased frequencies of epigenetic changes and imprinting disorders in children born after ART.

Outcome of assisted reproduction

In-vitro fertilisation has been done for nearly 30 years; in developed countries at least 1% of births are from assisted reproductive therapies (ART). These children now represent a substantial proportion of the population but little is known about their health. Some of the morbidity associated with ART does not result from the techniques but from the underlying health risks of being subfertile. Much of the amplified risk associated with ART is related to high birth order. However, risk of intrauterine and subsequent perinatal complications is enhanced after ART, and urogenital malformations can be present in boys, even in singleton infants. No increase in discord or other difficulties within families has been recorded. Long-term follow-up of children born after ART to reproductive age and beyond is necessary.

Multiple gestations and late preterm (near-term) deliveries

Multiple gestations present unique challenges to the modern obstetrician. Many twin and high-order multiple pregnancies are delivered between 34 and 37 weeks' gestation either secondary to preterm labor or obstetrical complications necessitating intervention. Recognizing the increasing prevalence of multiple gestations and the impact of late preterm deliveries in modern practice, this review analyzes the impact of multiple pregnancies on perinatal outcomes, reviews the strategies to prevent preterm labor, and summarizes potential indications for late preterm delivery. In this paper, "late preterm" has been used instead of "near-term," as the former was considered more appropriate to reflect this subgroup of preterm infants in a workshop on this topic held in July 2005, organized by the National Institute of Child Health and Human Development.

Is embryo-cryopreservation really neutral? A new long-term effect of embryo freezing in mice: protection of adults from induced cancer according to strain and sex

BACKGROUND

Beneficial or harmful effects of embryo freezing have been described in man and animals, raising the question of the neutrality of this technique.

OBJECTIVE

We examined, in mice, the possibility that embryo freezing influences the probability of the emergence, in adults, of an induced urinary bladder cancer.

METHODS

The experiment was conducted in mice derived from embryos of two different genotypes. Females receiving embryos were parsed into two groups according to whether these embryos were cryopreserved or not. The derived adults received the chemical carcinogen N-butyl-N-4hydroxybutylnitrosamine (BBN), in the drinking water. Time to death since the onset of treatment was measured for each animal until the 300th day.

RESULTS

In females from one of the two strains tested, embryo freezing led to a favorable long-term effect on the probability of resistance to induced cancer.

CONCLUSION

This beneficial effect, taken together with other effects reported in the literature be they beneficial or harmful, suggests that embryo freezing in mice may not be neutral.

A prospective longitudinal study of the physical, psychomotor, and intellectual development of singleton children up to 5 years who were conceived by intracytoplasmic sperm injection compared with children conceived spontaneously and by in vitro fertilization

OBJECTIVE

To assess the somatic, psychomotor, and intellectual development of children conceived through intracytoplasmic single sperm injection (ICSI) over the whole preschool period.

DESIGN

Prospective, controlled, cohort study.

SETTING

Fertility clinic in Brussels, Belgium.

PATIENT(S)

Sixty-six ICSI-conceived children prospectively compared with 52 IVF-conceived and 59 spontaneously conceived children. All children were full-term singletons.

INTERVENTION(S)

Home visits by a trained psychologist. Standardized interviews. Assessments using the revised Brunet-Lézine scale and the revised Wechsler preschool and primary scale of intelligence.

MAIN OUTCOME MEASURE(S)

Physical growth and general health. Formal developmental and intellectual assessments.

RESULT(S)

Children conceived by ICSI were healthy: no significant differences appeared in the incidence of combined congenital malformations (11.3%), health problems (44.1%), surgical interventions (18.6%), and hospitalizations (6.8%), nor for the developmental assessments (mean developmental quotient at 9 months: 93.9; at 18 months: 102.0). For the intellectual assessments, the between-group differences disappeared when adjusted for levels of parental education (mean intelligence quotient at 3 years: 97.0; at 5 years: 103.3).

CONCLUSION(S)

This pilot study shows that throughout the preschool period, ICSI-conceived children have psychomotor and intellectual development similar to that of IVF-conceived and spontaneously conceived children. These conclusions need to be confirmed by multicenter studies.

Obstetric outcome and follow-up of children born after in vitro fertilization (IVF)

In vitro fertilization (IVF) is a well established and effective method for the treatment of infertility, but there is concern about the health of children born as a result of this procedure. The introduction of new technologies, such as intracytoplasmic sperm injection (ICSI), has increased concern that the offspring from such techniques may be at increased risk, particularly of malformations. Studies on obstetric and neonatal outcome and early infant development after IVF obtained from a Medline search were reviewed. Children born after IVF had a considerably higher risk of being born pre-term and with a lower birth weight than children conceived naturally. A high incidence of multiple births and maternal characteristics were the main factors responsible for the increase in adverse outcome. Novel strategies in assisted reproduction, including the development of single embryo transfer regimens and avoidance of multiple births, are required. There is also a need for further developmental follow-up of children born after assisted conception, especially those born after ICSI.

Follow-up of children conceived from cryopreserved embryos

Few reports have been published on the follow-up of children born after embryo cryopreservation. These present reassuring data but lack the methodology for definitive conclusions about the physical and psychological development of children conceived with this technique. Paediatric follow-up studies are difficult to organize, especially when choosing a well-matched control group. There are ethical problems with singularising these children by enrolling them into specific medical and psychological studies. Studies are troubled by unstandardised tools, multiple observers, poor matching criteria, poor follow-up rates, and insufficient power for the outcome measures, absence or inappropriate control group and insensitive tools of assessment. Adequate malformation studies on these children have not been performed. A birth registry needs to be established. Overall the wellbeing of these children is satisfactory. Continuing follow-up needs to be performed in countries performing embryo cryopreservation.

Obstetric outcome of pregnancies after the transfer of cryopreserved and fresh embryos obtained by conventional in-vitro fertilization and intracytoplasmic sperm injection

This study reports the obstetric outcome of pregnancies obtained after the transfer of cryopreserved or fresh embryos where the initial procedure was standard in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Pregnancies obtained after frozen IVF (n = 245) or frozen ICSI (n = 177) were compared with a control group of pregnancies after fresh embryo transfer in standard IVF (n = 245) and ICSI (n = 177) cycles were selected as controls. The controls were matched according to maternal age, parity and date of embryo transfer. In the standard IVF group, the biochemical pregnancy rates in the cryopreserved and fresh groups were 18.8 and 9.8% respectively (P < 0.01). In the ICSI group, the biochemical pregnancy rates in the cryopreserved and fresh groups were 16.4 and 6.8% respectively (P < 0.01). The miscarriage rates were comparable between the cryopreserved and fresh groups. However, in the frozen ICSI group the miscarriage rate (26.0%) was significantly higher than in the frozen conventional IVF group (13.1%) (P = 0.001). The frequencies of preterm deliveries, infants with very low birthweight and intrauterine deaths were similar in the groups. The low birthweight rates in the frozen IVF (16.1%) and ICSI (12.1%) groups were significantly lower than those in the fresh IVF (32.2%) and ICSI (32.7%) groups (P < 0.001). The major malformation rates in the frozen IVF (2.4%) and ICSI (2.9%) groups were not different from the major malformation rates in the fresh IVF (4.5%) and ICSI (2.4%) groups. In conclusion, the cryopreservation process had no negative impact on the outcome of pregnancies over 20 weeks of gestation. Long-term follow-up studies are needed in order to prove the safety of the freezing-thawing process.

Infertility and early parent-infant interactions

Approximately 50% of infertile couples will become parents through pregnancy or adoption, but they experience major difficulties while working towards this goal. Infertility treatments are associated with physical pain and psychological distress, and adoption procedures are prolonged and emotionally stressful. The extent to which these stressors alter the parenting of these couples is not known. The purpose of this study, therefore, was to examine the early parent-infant interactions in infertile couples who become parents through pregnancy or adoption. Two groups of infertile couples (30 who achieved pregnancy and 21 who adopted) and a group of 19 couples without fertility problems were observed interacting with their infants twice, 7 to 21 days after the infant's arrival and a week later, at a time when both parents were at home. Their babies were between 9 days and 5 months of age. Behaviours of the mother, father and infant were recorded every 10 seconds, beginning when the baby was picked up and ending when the baby was put down asleep or 1 1/2 hours had passed. Repeated measures ANOVAs were used to compare the three groups over the observations. There were no differences between fertile and infertile biological parents. Adopted infants showed more alertness, less sleeping, more smiles, and more looking than biological infants. Adoptive mothers spent less time as the sole interactor. Adoptive parents spent more time in playing with their infants and held and touched them less than did biological parents. Infertility, therefore, does not appear to affect early parenting. In general, the amounts of behaviours exhibited by infertile biological parents were very close to those of fertile parents. Differences in the behaviours of adoptive as compared to biological parents can best be explained as responses to the behaviours of their older infants, rather than as evidence of different parenting styles.

Postnatal growth and health in children born after cryopreservation as embryos

BACKGROUND

There is uncertainty about the health of children born from in-vitro fertilisation (IVF) with cryopreserved embryos. We investigated the postnatal growth and health (up to 18 months) of these children compared with those born after standard IVF with fresh embryos and those from spontaneous pregnancies.

METHODS

255 children from cryopreserved embryos were matched by maternal age, parity, single or twin pregnancy, and date of delivery with 255 children born after IVF with fresh embryos, and 252 children from spontaneous pregnancies. The main endpoint was growth; secondary endpoints were the prevalence of chronic illness, major malformations, cumulative incidence of common diseases, and development during the first 18 months. Growth was assessed by comparison with standard Swedish growth charts and by standard deviation scores.

FINDINGS

Growth features were similar for both singletons and twins in the three groups. There were 6 (2.4%) of 255, 9 (3.5%) of 255, and 8 (3.2%) of 252 major malformations in the cryopreserved group, standard IVF, and spontaneous groups, respectively (p=0.6 between the cryopreserved and standard IVF group). The prevalence of chronic diseases did not differ between the three groups, with 18.0%, 15.3%, and 16.7% of children with a chronic illness in the cryopreserved group, standard IVF, and spontaneous groups, respectively.

INTERPRETATION

The cryopreservation process does not adversely affect the growth and health of children during infancy and early childhood. Minor handicaps, behavioural disturbances, learning difficulties, and dysfunction of attention and perception cannot be ruled out at this age.

Children conceived by in vitro fertilisation after fresh embryo transfer

AIMS

To compare the outcome in in vitro fertilisation (IVF) children (after fresh embryo transfer) from multiple and singleton births with one another, and with normally conceived control children.

METHODS

A cohort of 278 children (150 singletons, 100 twins, 24 triplets and four quadruplets), conceived by IVF after three fresh embryos had been transferred, born between October 1984 and December 1991, and 278 normally conceived control children (all singletons), were followed up for four years after birth. They were assessed for neonatal conditions, minor congenital anomalies, major congenital malformations, cerebral palsy and other disabilities. Control children, all born at term, were matched for age, sex and social class.

RESULTS

The ratio of male:female births was 1.03. Forty six per cent of IVF children were from multiple births; 34.9% were from preterm deliveries; and 43.2% weighed less than 2500 g at birth. The IVF singletons were on average born one week earlier than the controls, weighed 400 g less, and had a threefold greater chance of being born by caesarean section. The higher percentage of preterm deliveries was largely due to multiple births and they contributed to neonatal conditions in 45.0% of all IVF children. The types of congenital abnormalities varied: 3.6% of IVF children and 2.5% of controls had minor congenital anomalies, and 2.5% of IVF children and none of the controls had major congenital malformations. The numbers of each specific type of congenital abnormality were small and were not significantly related to multiple births. IVF children (2.1%) and 0.4% of the controls had mild/moderate disabilities. They were all from multiple births, including two children with cerebral palsy who were triplets.

CONCLUSIONS

The outcome of IVF treatment leading to multiple births is less satisfactory than that in singletons because of neonatal conditions associated with preterm delivery and disabilities in later childhood. A reduction of multiple pregnancies by limiting the transfer of embryos to two instead of three remains a high priority.

Follow-up of a cohort of 422 children aged 6 to 13 years conceived by in vitro fertilization

OBJECTIVE

To contact the total cohort of children conceived by IVF-ET consecutively in our center between June 1981 and December 1988.

DESIGN

Retrospective study.

SETTING

Infertility unit of the department of Obstetrics and Gynecology, Antoine Béclère Hospital, Clamart, France.

PATIENT(S)

Complete information was obtained on 370 children. The percentage lost for follow-up was 9%.

INTERVENTION(S)

To assess the children's well-being, telephone interviews of the parents and questionnaires sent to the parents and/or pediatrician were used.

MAIN OUTCOME MEASURE(S)

Surgical procedures, malformation, height and weight, school performance.

RESULT(S)

The physical growth of these children showed no major pathological features, with only 2.2% of them being below 2 SD for weight and 0.3% for height. The rates of malformation were not significantly different between these children and the general population. School performance was good, with 92.2% presenting encouraging outcome. Fifty-eight percent of the parents of children aged 6 to 10 years old did not inform their children about the IVF nor did 34% of the parents of children aged 11 to 13. Subsequent to the birth of the IVF child, 30 patients (8.9%) had a spontaneous pregnancy. However, five of them (15.1%) were ectopic.

CONCLUSION(S)

This study reports, for the first time, reassuring data on the long-term assessment of a large group of older IVF-ET children conceived consecutively, with a low percentage of subjects lost for follow-up.