Live Birth Rate Following Bed Rest Versus Early Mobilization After Embryo Transfer: A Systematic Review And Meta-Analysis.

Embryo transfer (ET) is the final step of in vitro fertilization (IVF). Different strategies have been proposed to increase the likelihood of implantation, such as post-transfer bed rest. The objective of this manuscript was to compare the clinical outcomes of embryo transfers after IVF of patients offered rest vs. early ambulation. The patient, intervention, comparison, and outcome(s) (PICO) model was used to select the study population, which included women/couples submitted to IVF and prescribed bed rest or early ambulation. Only studies including live birth (LB) as an outcome were included (www.crd.york.ac.uk/PROSPERO/CRD42020188716) A systematic search for studies was conducted on MEDLINE, ClinicalTrials.gov, PubMed, and the Cochrane Library. A librarian coordinated the searches in May 2020, which considered articles published since 1995. All original peer-reviewed articles in English were included, regardless of study design. The search retrieved 27 citations, of which 14 were eligible for full-text analysis and four accepted for inclusion. The studies included data on 21,598 patients/cycles (rest: 20,138; early ambulation: 1,460). Patients prescribed bed rest had an LB rate of 43.6% vs. 52.5% in the individuals not offered bed rest. The meta-analysis yielded an odds ratio of 0.77 (95% CI 0.5-1.2), which means patients on bed rest were 23% less likely to have a LB; nevertheless, this difference was not statistically significant. Considering that there is no difference between the two strategies, there is no evidence to recommend bed rest after embryo transfer.

Association of ovarian stimulation and embryonic aneuploidy in in vitro fertilization cycles with preimplantation genetic testing: A narrative systematic review.

The impact of gonadotropins used for COS on the rate of embryo aneuploidy in patients without the negative effects of age as a confounding factor, is still a subject of lively debate. We ran a systematic search for studies in MEDLINE, PubMed, Google Scholar and the Cochrane Library. A librarian coordinated the search in December of 2020. We included all original peer-reviewed papers in English, irrespective of study-design. There were no restrictions concerning method of amplification or platform used to analyze the amplified DNA. We used the PICO model to select the study population. We included women/couples submitted to COS for IVF with the intention to genetically analyze her/their embryos through PGT. The primary outcome was the rate of aneuploidy. We used the Newcastle-Ottawa scale (NOS) score to evaluate the quality of the studies included. The search yielded 73 citations, and 14 were eligible for analysis, which included data on 4805 cycles. Media quality NOS score was 8. Although it has been demonstrated that natural cycles are associated with aneuploidy, it does seem that more robust stimulations are indeed associated with a higher proportion of aneuploidy. Nevertheless, a higher response is associated with an increased number of euploid embryos available for transfer, which translates into more embryo-transfer cycles with a prospective higher cumulative live birth rate. Further evidence is needed to ascertain if there is a negative impact of COS, especially at the cellular level.

Pseudomonas guariconensis sp. nov., isolated from rhizospheric soil.

We isolated a bacterial strain designated PCAVU11(T) in the course of a study of phosphate-solubilizing bacteria occurring in rhizospheric soil of Vigna unguiculata (L.) Walp. in Guárico state, Venezuela. The 16S rRNA gene sequence had 99.2 % sequence similarity with respect to the most closely related species, Pseudomonas taiwanensis, and 99.1 % with respect to Pseudomonas entomophila, Pseudomonas plecoglossicida and Pseudomonas monteilii, on the basis of which PCAVU11(T) was classified as representing a member of the genus Pseudomonas. Analysis of the housekeeping genes rpoB, rpoD and gyrB confirmed the phylogenetic affiliation and showed sequence similarities lower than 95 % in all cases with respect to the above-mentioned closest relatives. Strain PCAVU11(T) showed two polar flagella. The respiratory quinone was Q9. The major fatty acids were 16 : 0 (25.7 %), 18 : 1ω7c (20.4 %), 17 : 0 cyclo (11.5 %) and 16 : 1ω7c/15 : 0 iso 2-OH in summed feature 3 (10.8 %). The strain was oxidase-, catalase- and urease-positive, the arginine dihydrolase system was present but nitrate reduction, ß-galactosidase production and aesculin hydrolysis were negative. Strain PCAVU11(T) grew at 44 °C and at pH 10. The DNA G+C content was 61.5 mol%. DNA-DNA hybridization results showed values lower than 56 % relatedness with respect to the type strains of the four most closely related species. Therefore, the results of genotypic, phenotypic and chemotaxonomic analyses support the classification of strain PCAVU11(T) as representing a novel species of the genus Pseudomonas, which we propose to name Pseudomonas guariconensis sp. nov. The type strain is PCAVU11(T) ( = LMG 27394(T) = CECT 8262(T)).