The freezing method of cleavage stage embryos has no impact on the weight of the newborns.

PURPOSE: The aim of this study was to study the effect of the embryo freezing method on the birth weight of newborns from frozen embryo transfer (FET) cycles, and the pregnancy results of cleavage stage embryos cryopreserved by slow freezing or vitrification. METHODS: This is a retrospective cohort study undertaken in a University Hospital IVF unit using concurrently both the slow-freezing and the vitrification techniques. All frozen-thawed and vitrified-warmed day 2 and day 3 embryo transfers during the time period from 1 April 2009 to 31 November 2013 were included in the study. RESULTS: There was no statistically significant weight difference between newborns from vitrified or slow-frozen embryos (3588 vs 3670 g). A higher post-thaw viability rate was achieved after cryopreservation by the vitrification technique compared to the slow-freezing protocol (83.4 vs 61.4%). The miscarriage rate was lower in the vitrification group (15.7 vs 29.0%). The live birth rates were similar (19.5 vs 19.1%) in the slow-freezing and vitrification groups, respectively. Among vitrified embryos, 7.4 embryos needed to be thawed to produce one delivery; in the slow-freezing group, that number was 11.9. CONCLUSIONS: The freezing method has no impact on the weight of the newborn. With lower post-thaw survival rates and higher miscarriage rates, the slow-freezing cryopreservation protocol is inferior to the vitrification technique.

Male gender explains increased birthweight in children born after transfer of blastocysts.

STUDY QUESTION: Does extended embryo culture have a different effect on the birthweight of girls and boys? SUMMARY ANSWER: The mean birthweight of boys born after fresh and frozen-thawed blastocyst transfer was increased compared with those born after cleavage stage embryo transfer. This effect was not detected among girls. WHAT IS KNOWN ALREADY: Previous studies indicate that newborns from frozen-thawed cleavage stage embryos may present with a higher weight than newborns from fresh embryo transfers. With regard to fresh embryos, newborns after a blastocyst transfer have been reported as having higher birthweights than newborns from cleavage stage embryos. STUDY DESIGN, SIZE, DURATION: Retrospective multicentre case-control cohort study. All IVF/ICSI treatments were performed in the time-period from January 2008 to March 2014. PARTICIPANTS/MATERIALS, SETTING, METHODS: Birthweight of singletons born at full-term (≥37 weeks), after fresh or frozen blastocyst embryo transfers (n = 277), were compared with weights of children born after fresh or frozen cleavage stage embryo transfers (Day 2-3) (n = 277). The cases and controls were matched by delivery week, and by gender. Data of IVF/ICSI treatments, and the treatments' outcomes were collected and analysed. MAIN RESULTS AND THE ROLE OF CHANCE: The birthweight after a fresh blastocyst transfer was significantly higher (mean 3530.6 g) than that after a transfer of cleavage stage embryos (mean 3418.8 g; weight difference 111.8 g, P = 0.047). The weights of newborns after frozen-thawed blastocyst transfers (mean 3647.5 g) and the frozen-thawed cleavage stage embryo transfers (mean 3650.9 g), were similar (weight difference 3.4 g, P = 0.95). The boys born after transfer of frozen-thawed blastocysts had a significantly higher birthweight (mean 3767.9 g) than girls (3525.2 g; weight difference 242.7 g, P = 0.002), whereas the difference of birthweights between genders was only 13.5 g in cleavage stage (P = 0.863). The same effect was seen after fresh blastocyst transfers (weight difference 211.5 g, P = 0.011), but not after fresh Day 2-3 embryo transfers (weight difference 53.6 g, P = 0.478). LIMITATIONS, REASONS FOR CAUTION: The study material was large enough to detect differences between birthweights as a whole, but a larger study group would confirm these new findings. To avoid selection bias, the next possible control candidate, fulfilling the selection criteria, was included for matching cases and controls. We have matched the cases and controls by gender and gestational week at birth, with an aim to reduce their impact as confounding factors. WIDER IMPLICATIONS OF THE FINDINGS: Our findings of a similar weight at birth of newborns after frozen-thawed blastocysts and frozen-thawed cleavage stage embryos, when matching for age and duration of pregnancy, are novel. The gender of the newborn has an impact on the birthweight, and the extended embryo culture increases the weight difference between the genders, which is a new finding as well. STUDY FUNDING/COMPETING INTERESTS: The study was funded by the Fertility Society of Finland.

Leukocyte telomere length and its relation to food and nutrient intake in an elderly population.

BACKGROUND/OBJECTIVES: Shorter leukocyte telomere length (LTL) is associated with several chronic diseases, but only a few studies have assessed the association between dietary factors and LTL. Our objective was to study the association between fats, fruits, vegetables and LTL in a cross-sectional study design. We hypothesized that intakes of fruits and vegetables would be positively associated with LTL and that intakes of fats, and especially saturated fatty acids (SFAs), would be negatively associated with LTL. SUBJECTS/METHODS: LTL was measured by quantitative real-time polymerase chain reaction in 1942 men and women aged 57-70 years from the Helsinki Birth Cohort Study. We assessed the whole diet by a validated semiquantitative 128-item food-frequency questionnaire. RESULTS: In general, there were only a few significant results. However, total fat and SFA intake (P=0.04 and 0.01, respectively) were inversely associated with LTL in men adjusting for age and energy intake. In women, vegetable intake was positively associated with LTL (P=0.05). Men consuming the most butter and least fruits had significantly shorter telomeres than those consuming the lowest amounts of butter and highest amounts of fruits (P=0.05). We found no association between LTL and body mass index, waist-hip ratio, smoking, physical activity or educational attainment. CONCLUSIONS: In this cross-sectional study of elderly men and women, there were only a few statistically significant effects of diet, but in general they support the hypothesis that fat and vegetable intakes were associated with LTL.

Glycaemic index values in the Finnish food composition database: an approach to standardised value documentation.

BACKGROUND/OBJECTIVES: The glycaemic index (GI) is used to describe the blood glucose-raising potential of carbohydrate-containing foods. Only a few descriptions of the addition of GI values to national food composition databases (FCDBs) exist. We tested whether the value documentation framework established within the European Food Information Resource (EuroFIR) Network could be used for GI values when adding them to the Finnish FCDB. METHODS: The list of foods requiring GI values was based on the National FINDIET 2007 Survey data and extended with foods encoded in a food-frequency questionnaire used in other nationally representative studies. The minimum quality of GI measurements was verified when gathering values from various sources, using earlier defined criteria. If a measured GI value for a food was directly available, or could be imputed or estimated, the value was added to the Finnish FCDB and documented using core standard vocabularies of EuroFIR. The GI values of composite foods were calculated using recipe calculation software. RESULTS: A total of 2210 foods required a GI value. GI values for 1322 foods were available and added to the FCDB. The remaining 888 foods were composite foods and received a GI value through recipe calculation. The standard vocabularies describing the origin of the GI values, the methods used in their derivation and their qualitative characteristics were suitable for GI values. CONCLUSIONS: GI values can be added to FCDBs and documented using terms similar to those used for traditional food composition data. Standardised value documentation may provide transparency for GI database compilation processes.