Erratum: Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

[This corrects the article DOI: 10.1093/hropen/hoz037.].

Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children.

STUDY QUESTION: What is the effect of growth velocity (height and weight) in early infancy on metabolic end-points and endothelial function in children born after ART? SUMMARY ANSWER: Neonatal, infant and childhood growth is positively related to blood pressure in 9-year-old IVF/ICSI offspring, while growth in childhood was negatively associated with endothelial function. WHAT IS KNOWN ALREADY: Offspring of pregnancies conceived after ART are at risk for later cardiometabolic risk factors. It is well established that early growth is related to numerous later cardiometabolic risk factors such as high blood pressure. This concept is known as the Developmental Origin of Health and Disease theory. STUDY DESIGN SIZE DURATION: The relation between early growth and later cardiometabolic risk profile was studied in the MEDIUM-KIDS study, a prospective observational cohort study in children born after an IVF/ICSI treatment. In 131 children (48.1% males) at the average age of 9.4 years, cardiometabolic outcomes were assessed and growth data from birth until age 9 years were collected from child welfare centers. PARTICIPANTS/MATERIALS SETTINGS METHODS: The following cardiometabolic outcomes were assessed: blood pressure, skinfolds, lipid spectrum, hair cortisone and glucose and insulin levels. Data on maximum skin perfusion after transdermal delivery of acetylcholine as a measure of endothelial function were collected.Growth charts were obtained electronically from child welfare centers, which offer free consultations and vaccinations to all Dutch children. At these centers, height and weight are recorded at predefined ages. Growth was defined as z-score difference in weight between two time points. Multivariable linear regression analysis was used to model the relation between growth and cardiometabolic outcomes. The following growth windows were -studied simultaneously in each model: 0-1 month, 1-3 months, 3-6 months, 6-11 months, 11-24 months and 2-6 years. The model was adjusted for height growth in all intervals except for 0-1 month. MAIN RESULTS AND THE ROLE OF CHANCE: In multivariable linear regression analyses, multiple growth windows were positively associated with blood pressure, for example growth from 2-6 years was significantly related to systolic blood pressure: B = 4.13, P = 0.005. Maximum skin perfusion after acetylcholine was negatively associated with height-adjusted weight gain from 2 to 6 years: B = -0.09 (log scale), P = 0.03. Several growth windows (weight 1-3 months, 3-6 months, 6-11 months, 11-24 months, 2-6 years) were positively linked with total adiposity. Lipids, glucose tolerance indices and cortisone were not related to growth. LIMITATIONS REASONS FOR CAUTION: This study is of modest size and of observational nature, and we did not include a control group. Therefore, we cannot assess whether the observed associations are causal. It is also not possible to analyze if our observations are specific for, or exacerbated in, the ART population. Ideally, a control group of naturally conceived siblings of IVF/ICSI children should simultaneously be studied to address this limitation and to assess the impact of the ART procedure without the influence of parental (subfertility) characteristics. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study contribute to our understanding of the reported increased risk for hypertension in ART offspring. We speculate that early, accelerated growth may be involved in the reported increased risk for hypertension in ART offspring, with endothelial dysfunction as a possible underlying mechanism. However, additional research into the mechanisms involved is required. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes, grant number #6-FY13-153. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the paper. The authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Association of culture medium with growth, weight and cardiovascular development of IVF children at the age of 9 years.

STUDY QUESTION: Is embryo culture media used during an IVF/ICSI treatment associated with differences in growth, body composition and cardiovascular development as determined in 9-year-old singleton IVF children? SUMMARY ANSWER: The choice of in vitro culture medium for human embryos is associated with differences in body weight, BMI, truncal adiposity, waist circumference and waist/hip ratio at the age of 9, while no significant differences were observed in cardiovascular development. WHAT IS KNOWN ALREADY: Children born after IVF/ICSI have an increased risk of low birthweight, which is correlated with a higher risk of cardiovascular diseases. Some studies show that IVF children exhibit a significantly higher systolic and diastolic blood pressure and higher fasting glucose levels compared to naturally conceived children. After alternating assignment to G1™ Version 3 (Vitrolife) or K-SICM (Cook) embryo culture media, birthweight of the resulting children was significantly higher in the Vitrolife group and they remained heavier during the first 2 years of life. STUDY DESIGN, SIZE, DURATION: In this observational cohort study (MEDIUM-KIDS), parents of singletons from a previous study were approached for further follow-up after the ninth birthday of their child. The singletons were born after fresh embryo transfer of cleavage stage embryos resulting from an IVF/ICSI treatment performed between July 2003 and December 2006 in our clinic, when two different culture media were used alternately: either G1™ Version 3 (Vitrolife) or K-SICM (Cook). Follow-up measurements were performed between March 2014 and December 2016. PARTICIPANT/MATERIALS, SETTINGS, METHODS: Parents were invited to attend our clinic with their child for a single visit lasting ~2.5 h. Two experienced clinicians performed all measurements as part of the MEDIUM-KIDS study in a standardized way. Height and weight of the child was measured using calibrated scales, 4-point skinfold thickness measurements were measured in triplicate and waist and hip circumference were measured using a tape measure. The following cardiovascular parameters were measured in a standardized way: blood pressure, heart rate and endothelial function by skin laser-Doppler with iontophoresis using vasodilatory drugs. Cortisol and cortisone concentrations in hair were measured. A blood sample was taken after an overnight fast for insulin, glucose, TSH and lipid analysis. Blood samples of the IVF children were compared with a non-IVF control group. Differences between culture medium groups were analysed by Student's t-test and effects of confounders were analysed using multivariable regression analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 294 eligible children (168 Vitrolife and 126 Cook), 136 children (75 Vitrolife and 61 Cook) participated in the study. Baseline characteristics of the participating children from the Vitrolife and Cook group were similar. Birthweight was higher in the Vitrolife group, in keeping with the full cohort. After correction for confounders, the difference in weight and BMI attributable to culture medium was 1.58 kg (95% CI: 0.01-3.14) and 0.84 kg/m2 (95% CI: 0.02-1.67), respectively, with the Vitrolife children being heavier. Height and height corrected for age and gender (SDS scores) were similar in both groups. Furthermore, waist circumference was significantly higher in the Vitrolife group with a corrected difference of 3.21 cm (95%CI: 0.60-5.81) leading to a 0.03 increase (95% CI: 0.01-0.05) in waist/hip ratio. Subscapular skinfolds combined with suprailiacal skinfolds (defined as truncal adiposity), was also significantly higher in Vitrolife children (adjusted difference 3.44 cm [95% CI: 0.27-6.62]). Both systolic (adj. beta 0.364 [95% CI: -2.129 to 2.856],) and diastolic (adj. beta 0.275 [95% CI: -2.105 to 2.654]) blood pressures (mmHg) were comparable for the two groups. After an overnight fast, cholesterol, glucose, insulin, low and high-density lipoprotein, triglycerides and TSH were normal and similar in the two groups. Endothelial function in the microcirculation was compared by using maximum perfusion units corrected for the baseline value as a measure for vasodilatory capacity. There were no significant differences between the two groups. Cortisol and cortisone concentration in hair samples were comparable. LIMITATIONS, REASONS FOR CAUTION: A limitation of the original study was its pseudo-randomized design. This and the dwindling enthusiasm of families for participation (47.7% after 9 years) prevent us from drawing robust causal conclusions from the observed association. Nevertheless, to date this is oldest cohort of IVF/ICSI children where culture medium was allocated alternatingly and used in a blinded setting, to be studied. We believe that our participants are representative for the full cohort. The current number of participants was sufficient to rule out differences as little as 3 mmHg in systolic and diastolic blood pressures. WIDER IMPLICATIONS OF THE FINDINGS: This study underlines the importance of structured follow-up of IVF/ICSI children to further elucidate possible long-term health effects. Health professionals and culture medium manufacturers should be aware that small changes in culture conditions and culture medium composition for the early embryo can have long-term health effects. The similar cardiovascular results for the two groups are reassuring but the children may still be too young to detect differences in cardiovascular development. Prolonged follow-up and structured investigations up until adulthood are necessary to gain more insight and reassurance in the cardiovascular development of IVF offspring, although long-term follow-up will become more complicated by confounding life-style and environmental factors possibly influencing development. STUDY FUNDING/COMPETING INTEREST(S): The study was financially supported by the March of Dimes (Grant number #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

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

STUDY QUESTION: Do embryo culture media used during an IVF/ICSI treatment have an effect on cognitive development of singleton IVF children at 9 years of age? SUMMARY ANSWER: Cognitive development of children born after culture in two different embryo culture media is comparable. WHAT IS KNOWN ALREADY: Previously, we have shown that the culture medium used in an IVF/ICSI treatment affects birthweight and weight at 2 years of age after alternating assignment to embryo culture in either K-SCICM (Cook) or G1™ Version 3 (Vitrolife). Children with low birthweight are known to have an increased risk for learning disabilities. Data on cognitive development in general of children born after ART are still conflicting, and the only study reporting on the effects of culture medium on cognitive development shows significant differences in cognitive development between two culture medium groups. STUDY DESIGN SIZE DURATION: In this observational cohort follow-up study (MEDIUM-KIDS), parents of all singletons from our abovementioned study were approached after the ninth birthday of their child to participate in an additional follow-up study. Of the 294 eligible children included in the original study, 119 children (70 Vitrolife and 49 Cook) participated in the current study. PARTICIPANTS/MATERIALS SETTING METHODS: All follow-up measurements were performed between March 2014 and December 2016. CITO (Dutch Central Institute for Test Development) developed the Dutch pupil monitoring system, which involves nationwide independent, standardized, academic achievement score tests to monitor the child's school performance twice a year at fixed time points from third grade onward. The tests include language skills (vocabulary and orthography), mathematics and reading capability and comprehension. Results from the tests performed between third and sixth grades, expressed as ability scores, were obtained from the school. To investigate school performance development over the years, we used a mixed effects multilevel model. The least complex model with the best fit was selected to analyze whether culture medium affects cognitive development in our cohort. The study had enough power to detect a difference in ability score that reflects at least one performance category between the two groups. MAIN RESULTS AND THE ROLE OF CHANCE: No differences were seen in baseline characteristics between participants and non-participants (both parental and children characteristics). For all domains, the random intercept model was used. All analyses showed comparable results for the two culture medium groups. No significant differences were observed for any of the cognitive development domains, even after correction for potential confounders. Parental level of education was higher in the IVF group (45%) if compared to the national average level of education (35%), which most likely explains the higher CITO scores for the IVF children if compared to the National ability scores. LIMITATIONS REASONS FOR CAUTION: A limitation of the study was its pseudo-randomized design and the relatively low participation rate of 40.5%. This and the number of missing data prevent us from drawing robust causal conclusions. However, as this is the first and therewith oldest cohort of children where culture medium was allocated alternatingly and used in a blinded setting, in the same period, with all other conditions identical this study gives up until now the best available evidence. WIDER IMPLICATIONS OF THE FINDINGS: Our study analyzes the effects of culture medium on school performance of children born after IVF/ICSI in a prospective cohort study. Although further research on long-term academic skills and also on behavior is essential, our results are reassuring and should make parents of children born after IVF/ICSI feel comfortable with their children's cognitive development. STUDY FUNDING/COMPETING INTERESTS: The study was financially supported by the March of Dimes (Grant no. #6-FY13-153). The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: NTR4220.

Improving external cephalic version for foetal breech presentation.

OBJECTIVES: If success rate of external cephalic version (ECV) increases, the rate of primary caesarean sections -declines. The aims of this retrospective cohort study were to evaluate the ECV and to identify factors associated with the success rate of ECV for breech presentation at term. The second aim of this study was to analyse the outcome of labour of all patients with a foetus in breech near term. METHODS: All women with a foetus in breech near or at term were included. Logistic regression analyses were -performed to identify the association between patient characteristics and success rate of ECV. RESULTS: The overall rate of successful ECV's was 19%. Foetal and maternal complications after ECV were negligible. BMI, type of breech and amount of amniotic fluid were significantly correlated with a successful ECV. The rate of primary caesarean sections for the group of patients who underwent an ECV was lower than the rate in the group who did not (52.9% vs. 79.6%). The rate of spontaneous deliveries was increased after ECV (36% versus 12%). After successful ECV the rate of spontaneous deliveries was 75%; after unsuccessful ECV 26.8%. CONCLUSION: The overall rate of successful ECV was low (19%). BMI, type of breech and amount of amniotic fluid were significantly correlated with a successful ECV. The rate of primary caesarean sections was significantly lower in patients with ECV (52.9% versus 79.6%). The rate of spontaneous deliveries was significantly higher (36% -versus 12%).