Two-year development of children conceived by IVM: a prospective controlled single-blinded study.

STUDY QUESTION: Is there a difference in mental development of children conceived by IVM in comparison to IVF or ICSI, independently, at the age of 2 years? SUMMARY ANSWER: No differences could be found in mental development of IVM children compared to IVF and IVM children compared to ICSI as well. WHAT IS KNOWN ALREADY: Only few retrospective or non-controlled studies addressed the health of IVM children and did not show a negative impact of the IVM procedure. STUDY DESIGN, SIZE, DURATION: Prospective controlled single-blinded study including 63 pregnancies (21 per IVM, IVF and ICSI groups) with 70 children expected. Examinations of 62 embryos at first trimester screening, of 57 fetuses at 21st week of pregnancy, of 60 children at birth and of 37 children at their second birthday were performed during the study period from January 2009 until October 2016. Bayley score at the age of 2 was the primary outcome parameter. Data of 40 children after spontaneous conception from a previous prospective unrelated study were further used as control at 2 years examination and compared to the pooled ART group (IVM, IVF and ICSI). PARTICIPANTS/MATERIALS, SETTING, METHODS: Twenty-one IVM pregnancies achieved in the study period were included. For each of them, the following IVF- and ICSI pregnancies were recruited as controls. Ultrasound examinations during pregnancy, examinations of newborns and of children around their second birthday were done by blinded prenatal specialists, pediatricians and neuropediatricians, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: Children conceived after IVM did not show differences during embryonic development, at birth nor in their neuropediatric development at the age of 2 compared to their counterparts after IVF and after ICSI (Bayley score 91.3 ± 21.0 for IVM, 96.8 ± 13.2 for IVF and 103.9 ± 13.1 for ICSI) and of the pooled ART group compared to children after spontaneous conception (96.6 ± 16.4 ART and 103.2 ± 9.4 spontaneous conception). When analyzing singleton pregnancies only, again no differences during pregnancy, at birth and at their 2-year evaluation were detected between IVM versus IVF and IVM versus ICSI. LIMITATIONS, REASONS FOR CAUTION: Due to the small sample size data must be interpreted with caution. To allow a confirmative answer that there are no health risks for children conceived by IVM, large multicenter cohort or registry-based studies are urgently needed. WIDER IMPLICATIONS OF THE FINDINGS: The study adds further information to previous uncontrolled or retrospective studies, which were unable to detect risks for the health of IVM children. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by the 'Deutsche Forschungsgemeinschaft' (DFG): STR 387/4-1. G.R. receives royalties from Pearson Assessment Germany (editor fee for Bayley-III). The other authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Work-relief ratios and imbalances of load application in sport climbing: another link to overuse-induced injuries?

An imbalanced load application of the upper extremity may contribute to overuse-induced injuries of the fingers. Thus, the present study evaluated load-application symmetry between the right and the left hand and its work-relief ratios (WRR) depending on climbing ability and pre-exhaustion level. Twenty-eight sport climbers (age: 29 ± 8 years; body mass index: 22 ± 2 kg/m(2); years of climbing: 10 ± 6; climbing level: 6+ UIAA to 9 UIAA) were assigned to a group of recreational (≤8-UIAA, n = 14) or a group of ambitious (≥8 UIAA, n = 14) climbers. Blood lactate and perceived exertion level were recorded at the end of the climbing attempt. Load application and WRR were derived from video analysis separately for the left and the right hand. Differences in load-application time between the left (47 ± 4%) and the right (53 ± 4%) hand (P < 0.001) were observed. Irrespective of side differences, the overall WRR was 5:1. Increasing climbing level leads to a more symmetric load application (r = -0.42, P < 0.03). Differences of lactate concentration and exertion level were found between the pre- and the non-pre-exhausted group. Depending on climbing ability and exhaustion level, load application for the dominant hand (right) prevails. Further longitudinal studies should focus on imbalanced load application and overuse-induced climbing injuries.