***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To determine whether altered follicular environment is associated with ovarian reserve or maternal age . DESIGN Prospect i ve study examining follicular fluid ( FF ) composition and follicular cell metabolism . SETTING University research department and private IVF clinic . PATIENT(S ) Women ( n = 54 ) undergoing routine IVF treatment were allocated to one of three groups based on ovarian reserve and maternal age . INTERVENTION(S ) Surplus FF , granulosa cells ( GC ) , and cumulus cells ( CC ) were collected . MAIN OUTCOME MEASURE(S ) Follicular fluid concentrations of carbohydrates , hormones , and selected ions . Metabolic analysis and gene expression of GCs and CCs . RESULT ( S ) Compared to women < 35 years with normal ovarian reserve , FF glucose levels were significantly decreased and lactate and progesterone ( P4 ) concentrations significantly increased in women with reduced ovarian reserve or advanced maternal age , whereas GC and CC glucose uptake , lactate production , and phosphofructokinase platelet gene expression were significantly increased . Granulosa cell P4 production from women with reduced ovarian reserve or advanced maternal age was decreased ; however , in CCs the reverse was observed with increased gene expression in P4 receptor , prostagl and in E receptor-2 , cytosolic phospholipase A2 , and tumor protein 53 . CONCLUSION ( S ) Women with either reduced ovarian reserve or advanced maternal age have altered follicular cell metabolism , FF metabolites , and P4 production . This perturbed environment may be responsible for impaired oocyte developmental competence and subsequent embryo development BACKGROUND IVF is limited by low success rates and an unacceptably high multiple pregnancy rate . These outcomes would be improved significantly if a single embryo of high viability could be replaced in each treatment cycle , but widespread acceptance of such a policy is hindered by the lack of predictive factors for embryo selection . We have conducted a retrospective clinical study of a novel non-invasive method of embryo selection based on the depletion/appearance of amino acids in the culture medium . METHODS Fifty-three cycles of IVF treatment using ICSI were studied . Embryos were cultured for 24 h in 4 microl drops of medium containing a physiological mixture of 18 amino acids . The spent medium was analysed for amino acid content by high performance liquid chromatography . RESULTS The turnover of three amino acids , Asn , Gly and Leu , was significantly correlated with a clinical pregnancy and live birth . These correlations were independent of known predictors , such as female age , basal levels of FSH , embryo cell number and embryo morphological grade . CONCLUSIONS Non-invasive assay of amino acid turnover has the potential to improve significantly the prospect i ve selection of the most viable embryos , or single embryo , for replacement in an IVF cycle OBJECTIVE To find new c and i date molecules to assess embryo viability in a noninvasive manner . DESIGN Prospect i ve , blinded study with r and omized sample collection . SETTING University research center . PATIENTS ( S ) Ninety embryos implanted in 53 r and omly selected patients ( mean ± SD age , 32.3 ± 5.1 years ) were analyzed . INTERVENTION(S ) Superovulation treatment was initiated by the administration of the GnRh agonist triptorelin and individual dosages of recombinant FSH . Ovulation was induced by the injection of hCG . Oocytes were fertilized by intracytoplasmic sperm injection . MAIN OUTCOME MEASURE(S ) Liquid chromatography coupled mass spectrometric quantification of the α-1 fragment of human haptoglobin in the culture medium . RESULT ( S ) A novel polypeptide marker was found that might be helpful to differentiate between potentially viable and nonviable embryos . This molecule was identified with t and em mass spectrometry as the α-1 fragment of human haptoglobin . Significant correlation was found in the amount of the peptide fragment and the outcome of pregnancy . In the culture media of embryos that were assigned in the biochemical assay as nonviable ( according to the amount of the haptoglobin fragment ) , there were no pregnancies detected ; this assay revealed a 100 % successful selection of the nonviable embryos . In the group assigned as viable , the rate of pregnancy was 54.7 % . CONCLUSION ( S ) Viability of the embryo during the IVF process is assessed by microscopic inspection , result ing in a pregnancy rate of 25%-30 % . Detection and quantitation of the α-1 haptoglobin fragment of the culture medium proved to be a useful additional method for identifying nonviable embryos , increasing the success rate to 50 % Objective To evaluate human oocyte ability to undergo fertilization and subsequent preimplantation embryonic development in relation to a wide panel of follicular fluid ( FF ) arachidonic acid derivatives ( AAD ) and linoleic acid derivatives ( LAD ) of prospect ively selected patients undergoing intracytoplasmic sperm injection ( ICSI ) .  Methodology Study was design ed as a two center ( a university clinic and a private clinic ) prospect i ve study . 54 women of 181 consecutive couples undergoing ICSI were prospect ively found to be eligible for analysis . ' One follicle – one retrieved oocyte – one result ing embryo ' approach was used . Each individual follicle was aspirated independently and matched to an oocyte growing in this particular follicular milieu . FF sample s were assessed for AAD and LAD by high-performance liquid chromatography ; additionally , activity of secretory phospholipase A ( sPLA2 ) was determined by enzyme-linked immunosorbent assay . Principal Findings Increased activity of sPLA2 and significantly higher AAD and LAD levels were found in FF of oocytes that did not show two pronuclei or underwent degeneration after ICSI in comparison to oocytes with the appearance of two pronuclei . Receiver operating characteristics curve analysis identified acids with the highest sensitivity and specificity : 5oxo-hydroxyeicosatetraenoic , 16-hydroxyeicosatetraenoic , 9-hydroxyoctadecadieneoic and 12-hydroxyeicosatetraenoic . No significant differences between AAD and LAD related to embryo quality were found . Conclusions / Significance Our study demonstrates for the first time that elevated concentrations of AAD and LAD in FF at the time of oocyte retrieval significantly decrease the ability of oocytes to form pronuclei after ICSI . This may serve as a new tool for non-invasive assessment of oocyte developmental capacity . However , levels of AAD and LAD are not associated with subsequent embryo quality or pregnancy rate , and therefore more studies are needed to determine their usefulness in human IVF procedure OBJECTIVE To determine whether follicular fluid ( FF ) cortisol levels affect cumulus cell ( CC ) lipid content during oocyte meiotic resumption , and whether CCs express genes for glucocorticoid action . DESIGN Prospect i ve cohort study . SETTING Academic medical center . PATIENT(S ) Thirty-seven nonobese women underwent ovarian stimulation for in vitro fertilization ( IVF ) . INTERVENTION(S ) At oocyte retrieval , FF was aspirated from the first follicle ( > 16 mm in size ) of each ovary and pooled CCs were collected . MAIN OUTCOME MEASURE(S )  Follicular fluid cortisol and cortisone analysis  was performed with the use of liquid chromatography-t and em mass spectrometry . CCs were stained with lipid fluorescent dye Bodipy FL C16 to determine lipid content with the use of confocal microscopy . Quantitative real-time polymerase chain reaction was used to detect CC gene expression of 11β-hydroxysteroid dehydrogenase ( 11β-HSD ) types 1 and 2 , glucocorticoid receptor ( NR3C1 ) , lipoprotein lipase ( LPL ) , and hormone-sensitive lipase ( HSL ) . RESULT ( S ) Adjusting for maternal age , FF cortisol levels negatively correlated with CC lipid content and positively correlated with numbers of total and mature oocytes . CCs expressed genes for 11β-HSD type 1 as the predominant 11β-HSD isoform , NR3C1 , LPL , and HSL . CONCLUSION ( S ) FF cortisol levels may regulate CC lipolysis during oocyte meiotic resumption and affect oocyte quality during IVF BACKGROUND Transfer of several  embryos  after  IVF  results in a high multiple birth rate associated with increased morbidity and high costs for the neonatal care . In a previous r and omized trial we demonstrated that a single embryo transfer ( SET ) strategy , including one fresh single embryo transfer and , if no live birth , one additional frozen-thawed SET , result ed in a live-birth rate that was not substantially lower than after double embryo transfer ( DET ) but markedly reduced the multiple birth rate . METHODS We compared costs for maternal health care and productivity losses and paediatric costs for the SET and DET strategies . In addition , maternal and paediatric outcomes between the two groups were compared . RESULTS The SET strategy result ed in lower average total costs from treatment until 6 months after delivery . There were a few more deliveries with at least one live-born child in the DET group . The incremental cost per extra delivery in the DET alternative was high , 71 940 . The rates of prematurely born and low birthweight children were significantly lower with the SET strategy . There were also markedly fewer maternal and paediatric complications in the SET group . CONCLUSIONS The SET strategy is superior to the DET strategy , when number of deliveries with at least one live-born child , incremental cost-effectiveness ratio and maternal and paediatric complications are taken into consideration . The findings do not support continuing transfers of two embryos in this group of patients Background Infertility is a problem concerning 10 - 15 % of the individuals in the fertile period . This study investigated effects of proinflammatory factors as well as lipid hydroperoxides ( LPO ) levels upon  in vitro fertilization ( IVF ) success . Material s and Methods In this prospect i ve , non-r and omized , controlled clinical study , sera obtained from 26 fertile ( group-1 ) , 26 infertile women before ( group-2 ) and after ( group-3 ) IVF treatment were analyzed . Leptin , leptin receptor , resistin , tumor necrosis factor-alpha ( TNF-α ) , and C-reactive protein ( CRP ) were analyzed using enzyme-linked immunosorbent assay ( ELISA ) . LPO was determined spectrophotometrically . Mann- Whitney U test , paired sample s t test , Wilcoxon signed-rank test as well as Pearson correlation analysis by SPSS were performed for statistical analysis . Results TNF-α , resistin and LPO levels increased ( P=0.020 , P=0.003 , P=0.001 , respectively ) in group-3 compared to group-2 . A significant increase in LPO was noted both in group-2 and -3 compared to controls ( P=0.000 ) . LPO were higher in non-pregnants than pregnants in group-2 . For pregnants , significant correlations were observed between leptin and resistin in group-2 and TNF-α and leptin in group-3 . None of these correlations were found for the women , who could not conceive . Conclusion LPO , leptin-resistin correlation , associations with TNF-α may be helpful during the interpretation of IVF success rates STUDY QUESTION Are bile acids ( BA ) and their respective subspecies present in human follicular fluid ( FF ) and do they relate to embryo quality in modified natural cycle IVF ( MNC-IVF ) ? SUMMARY ANSWER BA concentrations are 2-fold higher in follicular fluid than in serum and ursodeoxycholic acid ( UDCA ) derivatives were associated with development of top quality embryos on Day 3 after fertilization . WHAT IS KNOWN ALREADY Granulosa cells are capable of synthesizing BA , but a potential correlation with oocyte and embryo quality as well as information on the presence and role of BA subspecies in follicular fluid have yet to be investigated . STUDY DESIGN , SIZE , DURATION Between January 2001 and June 2004 , follicular fluid and serum sample s were collected from 303 patients treated in a single academic centre that was involved in a multicentre cohort study on the effectiveness of MNC-IVF .  PARTICIPANTS / MATERIAL S , SETTING , METHODS Material from patients who underwent a first cycle of MNC-IVF was used . Serum was not stored from all patients , and the available material comprised 156 follicular fluid and 116 matching serum sample s.  Total BA and BA subspecies were measured in follicular fluid and in matching serum by enzymatic fluorimetric assay and liquid chromatography-mass spectrometry , respectively . The association of BA in follicular fluid with oocyte and embryo quality parameters , such as fertilization rate and cell number , presence of multinucleated blastomeres and percentage of fragmentation on Day 3 , was analysed . MAIN RESULTS AND THE ROLE OF CHANCE Embryos with eight cells on Day 3 after oocyte retrieval were more likely to originate from follicles with a higher level of UDCA derivatives than those with fewer than eight cells ( P < 0.05 ) . Furthermore , follicular fluid levels of chenodeoxycholic derivatives were higher and deoxycholic derivatives were lower in the group of embryos with fragmentation compared with those without ( each P < 0.05 ) . Levels of total 
    Output:
    
According to current trials in women undergoing ART , there is insufficient evidence to show that metabolomic assessment of embryos before implantation has any meaningful effect on rates of live birth , ongoing pregnancy , or miscarriage rates .
At the moment , there is no evidence to support or refute the use of this technique for subfertile women undergoing ART .