Blood pressure and anthropometrics of 4-y-old children born after preimplantation genetic screening: follow-up of a unique, moderately sized, randomized controlled trial

Metabolic Profiles of Offspring Born From Biopsied Embryos from Toddlerhood to Preschool Age

CONTEXT

Embryo biopsy, which is necessary for preimplantation genetic testing (PGT), has not been fully investigated regarding its potential influences and safety. Previous studies of children born from biopsied embryos (PGT children) have primarily centered around their growth and neuropsychological development, while there remains limited knowledge concerning their endocrine and metabolic parameters.

OBJECTIVE

This study aims to examine the effect of trophectoderm (TE) biopsy on metabolic outcomes for PGT children.

METHODS

A total of 1267 children from the Center for Reproductive Medicine, Shandong University, who were conceived through in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) with and without PGT, were analyzed in this study. Three sets of measurements pertaining to growth and metabolism were taken at each predetermined follow-up time point. The linear regression models within a generalized estimating equation were employed to examine the associations between the PGT and each outcome measure and the approach of false discovery rate was used to correct for multiple comparisons.

RESULTS

After controlling for confounding factors and correcting for multiple comparisons, no statistically significant difference was identified in any of the measured variables between the PGT children and children conceived by IVF alone (IVF children) and children conceived through IVF using ICSI (ICSI children). The same is true also for age- or sex-based subgroup analyses.

CONCLUSION

Between the ages of 1 and 5 years, there are no clinically adverse metabolic outcomes observed in PGT children, and their metabolic profiles are essentially identical to those of IVF children and ICSI children.

Obstetric, neonatal, and child health outcomes following embryo biopsy for preimplantation genetic testing

BACKGROUND

Preimplantation genetic testing (PGT) of embryos developed in vitro requires a biopsy for obtaining cellular samples for the analysis. Signs of cell injury have been described in association with this procedure. Thus, the consequences of the biopsy on obstetric and neonatal outcomes have been the subject of some quantitative analyses, although the reliability of data pooling may be limited by important issues in the various reports.

OBJECTIVE AND RATIONALE

The present review identifies evidence for whether pregnancies conceived after embryo biopsy are associated with a higher risk of adverse obstetric, neonatal, and long-term outcomes. Available evidence has been summarized considering manipulation at various stages of embryo development.

SEARCH METHODS

We used the scoping review methodology. Searches of article databases were performed with keywords pertaining to the embryo biopsy technique and obstetric, neonatal, and postnatal outcomes. Studies in which embryos were biopsied at different stages (i.e. both at the cleavage and blastocyst stages) were excluded. We included data on fresh and frozen embryo transfers. The final sample of 31 documents was subjected to qualitative thematic analysis.

OUTCOMES

Sound evidence is lacking to fully address the issues on the potential obstetric, neonatal or long-term consequences of embryo biopsy. For polar body biopsy, the literature is too scant to draw any conclusion. Some data, although limited and controversial, suggest a possible association of embryo biopsy at the cleavage stage with an increased risk of low birthweight and small for gestational age neonates compared to babies derived from non-biopsied embryos. An increase in preterm deliveries and birth defects in cases of trophectoderm biopsy was suggested. For both biopsy methods (at the cleavage and blastocyst stages), an increased risk for hypertensive disorders of pregnancy was found. However, these findings may be explained by confounders such as other embryo manipulation procedures or by intrinsic patient or population characteristics.

WIDER IMPLICATIONS

Since there is inadequate evidence to assess obstetric, neonatal, and long-term health outcomes following embryo biopsy, an invasive PGT strategy should be developed with a cautious approach. A non-invasive approach, based on the analysis of embryo cell-free DNA, needs to be pursued to overcome the potential limitations of embryo biopsy.

Obstetric and neonatal outcomes of pregnancies resulting from preimplantation genetic testing: a systematic review and meta-analysis

BACKGROUND

Preimplantation genetic testing (PGT) includes methods that allow embryos to be tested for severe inherited diseases or chromosomal abnormalities. In addition to IVF/ICSI and repeated freezing and thawing of the embryos, PGT requires a biopsy to obtain embryonic genetic material for analysis. However, the potential effects of PGT on obstetric and neonatal outcomes are currently uncertain.

OBJECTIVE AND RATIONALE

This study aimed to investigate whether pregnancies conceived after PGT were associated with a higher risk of adverse obstetric and neonatal outcomes compared with spontaneously conceived (SC) pregnancies or pregnancies conceived after IVF/ICSI.

SEARCH METHODS

PubMed, EMBASE, MEDLINE, Web of Science and The Cochrane Library entries from January 1990 to January 2021 were searched. The primary outcomes in this study were low birth weight (LBW) and congenital malformations (CMs), and the secondary outcomes included gestational age, preterm delivery (PTD), very preterm delivery (VPTD), birth weight (BW), very low birth weight (VLBW), neonatal intensive care unit (NICU) admission, hypertensive disorders of pregnancy (HDP), gestational diabetes, placenta previa and preterm premature rupture of membranes (PROM). We further pooled the results of PGT singleton pregnancies. Subgroup analyses included preimplantation genetic diagnosis (PGD), preimplantation genetic screening (PGS), cleavage-stage biopsy combined with fresh embryo transfer (CB-ET) and blastocyst biopsy combined with frozen-thawed embryo transfer (BB-FET).

OUTCOMES

This meta-analysis included 15 studies involving 3682 babies born from PGT pregnancies, 127 719 babies born from IVF/ICSI pregnancies and 915 222 babies born from SC pregnancies. The relative risk (RR) of LBW was higher in PGT pregnancies compared with SC pregnancies (RR = 3.95, 95% confidence interval [CI]: 2.32-6.72), but the risk of CMs was not different between the two groups. The pooled results for the risks of LBW and CMs were similar in PGT and IVF/ICSI pregnancies. The risks of PTD (RR = 3.12, 95% CI: 2.67-3.64) and HDP (RR = 3.12, 95% CI: 2.18-4.47) were significantly higher in PGT pregnancies compared with SC pregnancies. Lower gestational age (mean difference [MD] = -0.76 weeks, 95% CI -1.17 to -0.34) and BW (MD = -163.80 g, 95% CI: -299.35 to -28.24) were also noted for PGT pregnancies compared with SC pregnancies. Nevertheless, compared with IVF/ICSI pregnancies, the risks of VPTD and VLBW in PGT pregnancies were significantly decreased by 41% and 30%, respectively, although the risk of HDP was still significantly increased by 50% in PGT pregnancies compared with IVF/ICSI pregnancies. The combined results of obstetric and neonatal outcomes of PGT and IVF/ICSI singleton pregnancies were consistent with the overall results. Further subgroup analyses indicated that both PGD and PGS pregnancies were associated with a higher risk of PTD and a lower gestational age compared with SC pregnancies.

WIDER IMPLICATIONS

This meta-analysis showed that PGT pregnancies may be associated with increased risks of LBW, PTD and HDP compared with SC pregnancies. The overall obstetric and neonatal outcomes of PGT pregnancies are favourable compared with those of IVF/ICSI pregnancies, although PGT pregnancies were associated with a higher risk of HDP. However, because the number of studies that could be included was limited, more randomised controlled trials and prospective cohort studies are needed to confirm these conclusions.

Developmental outcome of 9-year-old children born after PGS: follow-up of a randomized trial

STUDY QUESTION

Does Day-3 cleavage-stage PGS affect neurodevelopment of 9-year-old IVF offspring?

SUMMARY ANSWER

We did not find evidence of adverse consequences of Day-3 cleavage-stage PGS on neurodevelopment of 9-year-old IVF offspring, although children born after IVF with or without PGS often had a non-optimal neurological condition.

WHAT IS KNOWN ALREADY

Knowledge on long-term sequelae for development and health of children born following PGS is lacking. This is striking as evidence accumulates that IVF itself is associated with increased risk for impaired health and development in the offspring.

STUDY DESIGN SIZE, DURATION

This prospective, assessor-blinded, multicentre, follow-up study evaluated development and health of 9-year-old IVF children born to women who were randomly assigned to IVF with PGS (PGS group) or without PGS (control group). The follow-up examination at 9 years took place between March 2014 and May 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In total, 408 women were included and randomly assigned to IVF with or without Day-3 cleavage-stage PGS. This resulted in 52 ongoing pregnancies in the PGS group and 74 in the control group. In the PGS group, 59 children were born alive; in the control group, 85 children were born alive. At the age of 9 years, 43 children born after PGS and 56 control children participated in the study. Our primary outcome was the neurological optimality score, a sensitive measure of neurological condition assessed with a standardized, age-specific test (Touwen test). Secondary outcomes were adverse neurological condition (neurologically abnormal and the complex form of minor neurological dysfunction), cognitive development (intelligence quotient and specific domains), behaviour (parental and teacher's questionnaires), blood pressure and anthropometrics.

MAIN RESULTS AND THE ROLE OF CHANCE

Neurodevelopmental outcome of PGS children did not differ from that of controls; the neurological optimality scores (mean values [(95% CI]: PGS children 51.5 [49.3; 53.7], control children 53.1 [50.5; 55.7]) were not significantly different. The prevalences of adverse neurological outcome (in all but one child implying the presence of the complex form of minor neurological dysfunction) did not differ between the groups (PGS group 17/43 [40%], control group 19/56 [34%]), although the prevalence of complex minor neurological dysfunction in both groups was rather high. Also intelligence quotient scores of the two groups were not significantly different (PGS group 114 [108; 120]); control group 117 [109; 125]), and the behaviour, blood pressure and anthropometrics of both groups did not differ. Mean blood pressures of both groups were above the 60th percentile.

LIMITATIONS REASONS FOR CAUTION

The power analysis of the study was not based on the number of children needed for the follow-up study, but on the number of women who were needed to detect an increase in ongoing pregnancy rates after PGS. In addition, our study evaluated embryo biopsy in the form of PGS at cleavage stage (Day-3 embryo biopsy), while currently PGS at blastocyst stage (Day-5 embryo biopsy) is recommended and increasingly being used.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings indicate that PGS in cleavage stage embryos is not associated with adverse effects on neurological, cognitive and behavioural development, blood pressure and anthropometrics of offspring at 9 years. This is a reassuring finding as embryo biopsy in the forms of PGS and PGD is increasingly applied. However, both groups of IVF offspring showed high prevalences of the clinically relevant form of minor neurological dysfunction, which is a point of concern for the IVF community. In addition, our study confirms findings of others that IVF offspring may be at risk of an unfavourable cardiovascular outcome. These findings are alarming and highlight the importance of research on the underlying mechanisms of unfavourable neurodevelopmental and cardiovascular outcomes in IVF offspring.

STUDY FUNDING/COMPETING INTEREST(S)

The randomized controlled trial was financially supported by the Organization for Health Research and Development (ZonMw), The Netherlands (Grant number 945-03-013). The follow-up was financially supported by the University Medical Center Groningen (Grant number: 754510), the Cornelia Foundation, and the graduate schools BCN and Share, Groningen, The Netherlands. The sponsors of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. There are no conflicts of interest.

TRIAL REGISTRATION NUMBER

ISRCTN76355836.

Pregnancy and child developmental outcomes after preimplantation genetic screening: a meta-analytic and systematic review

BACKGROUND

In in vitro fertilization (IVF) treatment, preimplantation genetic diagnosis/screening (PGD/S) attempts to detect chromosomal abnormalities in embryos before implantation. Using the meta-analytic and qualitative review approaches, this study aims to evaluate the effect of PGD/S on clinical pregnancy, live births, and childhood outcomes.

METHODS

We conducted a literature search using 1) PubMed and other search engines, and 2) an ancestry search by tracking references cited in prior work. After screening the studies, we extracted information pertinent to the meta-analysis. We calculated the effect sizes for clinical pregnancy and live birth rates, and performed a moderation analysis by maternal age, type of genetic screening, and timing of the biopsy. For childhood outcomes, we conducted a systematic review of studies reporting the anthropometric, psychomotor, cognitive, behavioral, and family functioning of PGD/S children.

RESULTS

We included 26 studies for clinical pregnancy and live births, and 18 studies for childhood outcomes. Results indicated that women who underwent comprehensive chromosome screening-based PGD/S had significantly higher clinical pregnancy rates (rr 1.207, 95% CI 1.017-1.431) and live birth rates (rr 1.362, 95% CI 1.057-1.755) than those whose IVF treatment did not include PGD/S. Early childhood outcomes of PGD/S children did not differ from those of non-PGD/S children.

CONCLUSIONS

Comprehensive chromosome screening-based PGD/S can improve clinical pregnancy and live birth rates without adversely affecting functioning in childhood at least up to age 9. Results are discussed in the context of bioethical, financial, legal, and psychological issues surrounding PGD/S.

Cardiovascular health of 9-year-old IVF offspring: no association with ovarian hyperstimulation and the in vitro procedure

STUDY QUESTION

Are the in vitro procedure, ovarian hyperstimulation or a combination of these two associated with blood pressure (BP) of 9-year-old IVF children born to subfertile couples?

SUMMARY ANSWER

Our study demonstrates that ovarian hyperstimulation and the in vitro procedure are not associated with BP values in 9-year-old children born to subfertile couples.

WHAT IS KNOWN ALREADY

Possible long-term effects of IVF on child health and development have been studied relatively little. This is surprising, as it is known that environmental conditions may influence embryonic and foetal development which may result in health related problems in later life. Some studies suggested that IVF is associated with higher BP at pre-school age. Yet, it is unclear whether this may be also true for older children and if so, which component of IVF, i.e. the ovarian hyperstimulation, the embryo culture or a combination of these, attributes to this potentially less favourable BP.

STUDY DESIGN, SIZE, DURATION

The Groningen Assisted Reproductive Technology cohort-study is a prospective assessor-blinded study of children followed from before birth onwards. In total, 170 children were assessed at the age of 9 years. The attrition rate up until the 9-year-old assessment was 21%.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We evaluated cardiovascular health, focusing on BP (in mmHg and the internationally recognized percentiles of the US National High BP Education Program), heart rate and anthropometrics of 57 children born following controlled ovarian hyperstimulation-IVF/ICSI (COH-IVF/ICSI); 47 children born after modified natural cycle-IVF/ICSI (MNC-IVF/ICSI); and 66 children who were conceived naturally by subfertile couples (Sub-NC). Cardiovascular parameters were measured multiple times on one day. In addition, anthropometric data, including BMI and skinfold thickness, were collected.

MAIN RESULTS AND THE ROLE OF CHANCE

Systolic BP in mmHg did not differ between the COH-IVF/ICSI (mean 106.9, SD 6.7), MNC-IVF/ICSI (mean 104.8, SD 5.9) and Sub-NC (mean 106.3, SD 5.3) groups. In addition, systolic BP percentiles did not differ between the groups: COH-IVF/ICSI (mean 62.4, SD 20.2); MNC-IVF/ICSI (mean 56.3, SD 19.3); and Sub-NC (mean 62.3, SD17.8). Also, after adjustment for confounders BP in the three groups was similar. Heart rate and anthropometric values in the three groups did not differ. For instance, BMI values in the COH-IVF/ICSI-children were 16.3 (median value, range 13.0-24.7), in MNC-IVF/ICSI-children 16.1 (range 12.7-22.5) and in Sub-NC children 16.3 (range 12.7-24.0).

LIMITATIONS, REASONS FOR CAUTION

The size of our study groups does not allow for pertinent conclusions on the effect of ovarian hyperstimulation and the in vitro procedure. The lack of a fertile control group may be regarded as another limitation.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that ovarian hyperstimulation and in vitro procedures are not associated with cardiovascular health in 9-year-old. Yet, BP percentiles of the three groups were higher than the expected 50th percentile. This might indicate that children of subfertile couples have a higher BP than naturally conceived children.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financially supported by the University Medical Center Groningen (UMCG), the two graduate schools of the UMCG, BCN, 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.

Body composition and blood pressure in 6-year-old singletons born after pre-implantation genetic testing for monogenic and structural chromosomal aberrations: a matched cohort study

STUDY QUESTION

Does Day 3 embryo biopsy for pre-implantation genetic testing for monogenic (PGT-M) and structural chromosomal aberrations (PGT-SR) affect body composition and blood pressure readings of 6-year-old singletons?

SUMMARY ANSWER

This study of 87 PGT-M and PGT-SR conceived singletons showed no differences in anthropometric measurements and blood pressure readings in comparison with a matched cohort of peers born after ICSI without embryo biopsy.

WHAT IS KNOWN ALREADY

While neonatal outcomes after PGT conception have been found comparable to those after ICSI without embryo biopsy, only a few studies have reported outcomes after PGT at older ages. Moreover, embryo biopsy is also applied in couples who opt for PGT-M and PGT-SR and hence are not necessarily infertile. Health parameters and in particular body composition data in this group of children are lacking.

STUDY DESIGN SIZE DURATION

This single-centre matched-pair cohort study evaluated body composition of 6-year-old children born after fresh blastocyst embryo transfer with or without embryo biopsy performed at Day 3 for the purpose of PGT-M and PGT-SR. For each child born after embryo biopsy, a singleton born after transfer of a fresh ICSI embryo at the blastocyst stage and reaching the age of 6 years between May 2011 and June 2017 was matched as closely as possible for gender, age, maternal educational level and birth order.

PARTICIPANTS/MATERIALS SETTING METHODS

Anthropometry (weight, height, BMI, skinfold thickness, waist and mid-upper arm circumference) and blood pressure readings in a longitudinally followed cohort of 87 singletons conceived by PGT-M and PGT-SR and a pairwise matched sample of 87 children conceived by ICSI are described. Results are adjusted for current, neonatal and parental characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

From the 124 eligible PGT-M and PGT-SR families, 110 could be reached of whom 23 refused and 87 (87/110 = 79%) participated. All anthropometric measurements, including z-scores of BMI, waist and mid-upper arm circumference, were comparable between the PGT-M and PGT-SR (-0.23; 0.27; 0.17, respectively) and ICSI (-0.29; 0.11; 0.11, respectively) groups (all P > 0.05). Furthermore, indices of peripheral (triceps) and central (subscapular) adiposity derived from skinfold thickness were comparable (PGT-M and PGT-SR: 14.7 mm; 11.6 mm and ICSI: 15.5 mm; 11.5 mm) as well as the percentage total body fat mass derived from these (PGT-M and PGT-SR: 13.7% and ICSI: 13.9%) (all P > 0.05). Z-scores for blood pressure were also comparable between the PGT and ICSI groups (all P > 0.05). Results did not change when adjusted for neonatal (birthweight, birth order), current (age) and parental (smoking during pregnancy, parental BMI) characteristics. Hospitalization rate and surgical intervention rate were not different for PGT-M and PGT-SR children compared to matched peers born after ICSI.

LIMITATIONS REASONS FOR CAUTION

Although our study describes the largest cohort of singletons born after embryo biopsy worldwide, we were only able to detect moderate differences in anthropometrics and blood pressure with our sample size.

WIDER IMPLICATIONS OF THE FINDINGS

Although Day 3 embryo biopsy followed by blastocyst transfer is not associated with adverse outcomes regarding anthropometry and blood pressure, future studies should focus on outcomes in children born after trophectoderm biopsy and/or transfer of warmed embryos after vitrification.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts; all issued by the Vrije Universiteit Brussel (VUB). All co-authors, except M.B. declared no conflict of interest. M.B. has received consultancy fees from MSD, Serono Symposia and Merck. The Universitair Ziekenhuis Brussel (UZ Brussel) and the Centre for Medical Genetics have received several educational grants from IBSA, Ferring, Organon, Shering-Plough, Merck for establishing the database for follow-up research and organizing the data collection.

Cardiovascular and metabolic profiles of offspring conceived by assisted reproductive technologies: a systematic review and meta-analysis

OBJECTIVE

To evaluate cardiovascular and metabolic features of offspring conceived by in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI).

DESIGN

Literature review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Offspring from IVF-ICSI versus natural conception.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Systolic and diastolic blood pressure (SBP and DBP), cardiovascular function, body mass index (BMI), and lipid and glucose profiles.

RESULT(S)

We included 19 studies that had recruited 2,112 IVF-ICSI and 4,096 naturally conceived offspring, ranging from childhood to early adulthood. The blood pressure levels of IVF-ICSI offspring were statistically significantly higher than those of naturally conceived offspring (weighted mean differences and confidence intervals: 1.88 mm Hg [95% CI, 0.27, 3.49] for SBP and 1.51 mm Hg [95% CI, 0.33, 2.70] for DBP). In addition, cardiac diastolic function was suboptimal and vessel thickness was higher among IVF-ICSI offspring. Compared with the metabolism of naturally conceived offspring, IVF-ICSI offspring displayed comparable BMI, lower low-density lipoprotein cholesterol levels, and higher fasting insulin levels.

CONCLUSION(S)

Children conceived by IVF-ICSI manifested a minor yet statistically significant increase in blood pressure without the clustering of increased BMI or impaired lipid metabolism by early adulthood. Our findings indicate a risk of cardiovascular disease among IVF-ICSI offspring, which calls for longer-term follow-ups and further investigation.