Low oxygen concentrations for embryo culture in assisted reproductive technologies.
ABSTRACT During in vitro fertilisation (IVF) procedures, human preimplantation embryos are cultured in the laboratory. While some laboratories culture in an atmospheric oxygen concentration (˜ 20%), others use a lower concentration (˜ 5%) as this is more comparable to the oxygen concentration observed in the oviduct and the uterus. Animal studies have shown that high oxygen concentration could have a negative impact on embryo quality via reactive oxygen species causing oxidative stress. In humans, it is currently unknown which oxygen concentration provides the best success rates of IVF procedures, eventually resulting in the hightest birth rate of healthy newborns.
To determine whether embryo culture at low oxygen concentrations improves treatment outcome (better embryo development and more pregnancies and live births) in IVF and intracytoplasmic sperm injection (ICSI) as compared to embryo culture at atmospheric oxygen concentrations.
The Menstrual Disorders and Subfertility Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and PsycINFO electronic databases were searched (up to 4th November 2011) for randomised controlled trials on the effect of low oxygen concentrations for human embryo culture. Furthermore, reference lists of all obtained studies were checked and conference abstracts handsearched.
Only truly randomised controlled trials comparing embryo culture at low oxygen concentrations (˜ 5%) with embryo culture at atmospheric oxygen concentrations (˜ 20%) were included in this systematic review and meta-analysis.
Two review authors selected the trials for inclusion according to the above criteria. After that two authors independently extracted the data for subsequent analysis, and one author functioned as a referee in case of ambiguities. The statistical analysis was performed in accordance with the guidelines developed by The Cochrane Collaboration.
Seven studies with a total of 2422 participants were included in this systematic review. Meta-analysis could be performed with the data of four included studies, with a total of 1382 participants. The methodological quality of the included trials was relatively low. Evidence of a beneficial effect of culturing in low oxygen concentration was found for live birth rate (OR 1.39; 95% CI 1.11 to 1.76; P = 0.005; I(2) = 0%); this would mean that a typical clinic could improve a 30% live birth rate using atmospheric oxygen concentration to somewhere between 32% and 43% by using a low oxygen concentration. The results were very similar for ongoing and clinical pregnancy rates. There was no evidence that culturing embryos under low oxygen concentrations resulted in higher numbers of adverse events such as multiple pregnancies, miscarriages or congenital abnormalities.
The results of this systematic review and meta-analysis suggest that culturing embryos under conditions with low oxygen concentrations improves the success rates of IVF and ICSI, resulting in the birth of more healthy newborns.
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ABSTRACT: We aimed to determine whether embryo culture induces markers of cellular senescence and whether these effects were dependent on culture conditions.Journal of Assisted Reproduction and Genetics 08/2014; · 1.82 Impact Factor
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ABSTRACT: Objective To investigate the correlation between the estradiol (E2) level change after hCG administration and the live birth rate in GnRH agonist long or short protocols, and to explore the possible factors related to E2 dynamics after hCG administration during controlled ovarian hyperstimulation (COH). Study design A retrospective analysis was performed on 2868 patients who received IVF/intracytoplasmic sperm injection (ICSI) treatment with GnRH agonist long or short protocol. The patients were divided into three groups according to their serum E2 changes after hCG administration, and the live birth rates were compared among groups. The area under the receiver operating characteristic (ROC) curve was calculated to assess the predictive value of E2 change for the probability of live birth. Logistic regression analysis was also applied to exclude interference from various confounding factors. Finally, multivariate regression analysis was conducted to assess factors related to the E2 change after hCG administration. Results No significant difference was observed in live birth rates (4.26%, 36.38% or 30.81% in long protocol (P = 0.697); 25.81%, 26.71% or 30.81% in short protocol (P = 0.697)) among patients with increasing, plateauing or decreasing E2 responses after hCG administration. The area under the ROC curve for the E2 change in prediction of live birth rate was 0.506 in long protocol, or 0.524 in short protocol. Logistic regression analysis showed that the serum E2 change after hCG administration had no correlation with live birth rate. Multivariate regression analysis showed that the percentage of mature follicles (larger than 14 mm) and the duration of stimulation negatively correlated with the E2 change after hCG administration. Conclusions In GnRH agonist cycles, the serum E2 change after hCG administration had no correlation with live birth rate in fresh embryo transfer cycles, and this change negatively correlated with the percentage of mature follicles on the day of hCG administration.European Journal of Obstetrics & Gynecology and Reproductive Biology. 01/2014;
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ABSTRACT: In Western gender-neutral countries, the sex ratio at birth is estimated to be approximately 1.06. This ratio is lower than the estimated sex ratio at fertilization which ranges from 1.07 to 1.70 depending on the figures of sex ratio at birth and differential embryo/fetal mortality rates taken into account to perform these estimations. Likewise, little is known about the sex ratio at implantation in natural and assisted-reproduction-treatment (ART) cycles. In this bioessay, we aim to estimate the sex ratio at fertilization and implantation using data from embryos generated by standard in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in preimplantation genetic diagnosis cycles. Thereafter, we compare sex ratios at implantation and birth in cleavage- and blastocyst-stage-transfer cycles to propose molecular mechanisms accounting for differences in post-implantation male and female mortality and thereby variations in sex ratios at birth in ART cycles.Reproductive Biology and Endocrinology 06/2014; 12(1):56. · 2.41 Impact Factor