Outcome and feasibility of elective single embryo transfer (eSET) policy for the first and second IVF/ICSI attempts.

OBJECTIVE: This study assesses the outcome and the feasibility of an elective single embryo transfer (eSET) policy for the first and second IVF/ICSI attempts. STUDY DESIGN: This is a retrospective analysis performed on 611 couples attempting a first IVF cycle in Clermont-Ferrand University Hospital, France. eSET was offered to the couples when they had 2 embryos with at least one of good quality at day 2 for their first and second IVF/ICSI cycles. RESULTS: Among the couples selected for the study, 442 underwent an eSET and 341 a double embryo transfer (DET). The cumulative ongoing pregnancy rate (OPR) and the cumulative delivery rate (DR), including fresh and frozen embryo transfer, did not differ statistically between the two groups, respectively 40.7% and 30.9% in the eSET group and 42.5% and 34.6% in the DET group. The twin pregnancy rate was lower in the eSET group (0.7% vs. 21.2%; p<0.0001) and neonatal and obstetrical outcomes were better than in the DET group. For the first attempt, the global twin rate (including eSET and DET) was 7.1% and the proportion of eSET was high, 67.6%, but for the second attempt the eSET rate was only 16.9%, with an increased global twin rate of 21.4% (p=0.042). CONCLUSION: In a selected population an eSET strategy decreases the twin pregnancy rate without decreasing the delivery rate, with a better outcome for the infants than DET. However, eSET is well accepted by patients only for the first attempt even though the pregnancy rate is not statistically different for the second.

[Outcome of elective single or double embryo transfer in first and second IVF/ICSI cycles]. / Comparaison des résultats du transfert électif d'un ou de deux embryons lors des premières et secondes tentatives de FIV/ICSI.

BACKGROUND: The aim of the study is to compare the incidence of eSET (elective single embryo transfer) and DET (double embryo transfer) and their results about live birth and twin pregnancies between first and second IVF/ICSI cycles, in a selective population. These data allow analysing whether the extension of elective single embryo transfer in the second cycle is efficient. PATIENTS AND METHODS: Retrospective study about embryo transfers performed in first and second IVF/ICSI cycles in the IVF unity (CHU Clermont-Ferrand) between 1 January 2004 and 31 December 2006. Women belonging to couples considered have less than 36 years. On the second day of embryo development, at least two good quality embryos have been observed. After information about eSET and DET, couples give their written consent to the transfer of one or two embryos. Couples who have no live birth at the end of the first cycle have been followed up for the second cycle whether they correspond to the inclusions criteria. Analysis is performed with live birth rates by tentative (overall rate) and after one or two embryo transfer, cumulative live birth rate (including fresh and frozen embryo transfer, and twin pregnancy rate. RESULTS: An embryo transfer at the first IVF/ICSI cycle (report eSET/DET=0.5) has been performed for 513 patients. The overall cumulative live birth rate is 37.1%, without significant difference between eSET and DET (36.2% vs 35.7%, p=ns). The twin pregnancies rate is 12% (including 0% in eSET vs 24% in DET, p<0001). Two hundred and five patients have a second IVF/ICSI cycle (92.3% in DET and 7.7% in eSET). The overall cumulative live birth rate is 34.1% without difference between eSET and DET (31.3% vs 34.3%). The twin pregnancies rate is 22.5% and it is significantly higher compared with the first attempt (including 0% in ESET and 24.6% in DET). DISCUSSION AND CONCLUSION: The increased twin pregnancies rate during the second cycle is explained by the higher rate of DET. This may be explained by the non-acceptance by couples of a new eSET, despite acceptable results for live birth rate. We have to search for solutions to encourage its development like the reimbursement of more cycles when eSET is performed, or with regulations as in Belgium, because the information to the couples is not efficient.

Metallothionein and metal levels in liver, gills and kidney of Sparus aurata exposed to sublethal doses of cadmium and copper.

The levels of metallothionein (MT), a biomarker of metal exposure, and of Cd and Cu, known as MT inducers, were investigated in Sparus aurata intraperitoneally injected with 500 microg/kg of Cu and Cd for 2 days. MT and metal concentrations (Cd and Cu) were determined in liver, gills and kidney. MT levels were significantly increased in all investigated tissues, with the highest value in liver of Cu as Cd-treated fishes (3.56-fold and 3.3- fold, respectively). Metal concentrations were statistically different between all tissues. Highest metal concentrations were in the liver. The higher metal concentrations and MT induction levels support the main role of MT in metal homeostasis and detoxification.

Mixture toxicity assessment of cadmium and benzo[a]pyrene in the sea worm Hediste diversicolor.

In the present study, Hediste diversicolor biotransformation and anti-oxidant responses to acute exposure to cadmium (Cd) and to the polycyclic aromatic hydrocarbons benzo[a]pyrene (B[a]P) were investigated. Worms were submitted to 0.2, 0.4 and 1 microM of each contaminant and to their mixture during a period of test of 48h. Following biological responses were measured: (1) NADPH cytochrome c reductase (NADPH cyt c) activity, as phase I biotransformation parameter; (2) gluthathione-S-transferase (GST) activity as a phase II conjugation enzyme, (3) catalase activity as anti-oxidant response and (4) malondialdehyde accumulation (MDA) as lipid peroxydation marker. The cholinergic system was evaluated using the acetylcholinesterase activity (AChE). Exposure to the mixture resulted in low dose level additive effects on the investigated biomarkers. However, worms exposed to 1 microM of the single compounds and to their mixture exhibited the highest MDA accumulation and the lowest enzymatic biomarkers activities suggesting severe toxicological effects. These data should be carefully considered in view of the biological effects of mixture pollutants and particularly in marine sediment ecosystems.

Acute effects of benzo[a]pyrene on liver phase I and II enzymes, and DNA damage on sea bream Sparus aurata.

In the present study biotransformation and detoxification responses to acute exposure to the polycyclic aromatic hydrocarbons benzo[a]pyrene (B[a]P) were investigated in the liver of Sparus aurata (sea bream). Sexually immature gilthead sea bream were treated by intraperitoneal injection of B[a]P (20 mg kg(-1)) for 6, 12, 24, and 48 h. B[a]P accumulation was quantified in sea bream liver by mean of gas phase chromatography (GPC-MS) after the various exposure periods. The following biological responses were measured: (1) ethoxyresorufin-O-deethylase (EROD) activity, as a phase I biotransformation parameter; (2) liver glutathione S-transferase (GST) activity as a phase II conjugation enzyme. DNA damage was assessed over time using the single-cell gel electrophoresis comet assay. B[a]P bioaccumulation in the liver resulted in a biphasic curve with an increasing uptake up to 5.55 +/- 0.67 microg g(-1) dry weight after only 6 h exposure and 4.67 +/- 0.68 microg g(-1) dry weight after 48 h exposure. EROD activity showed a nonsymmetrical bell-shaped kinetic with a maximum at 24 h and lower but significant activities at 12 and 48 h with respect to control animals. Hepatic GST activities were only significant after 48 h exposure. Comet assay showed an increase in liver cells DNA damage with a maximum after 48 h exposure reaching up to 12.17 % DNA in the tail.

Acute effects of cadmium on liver phase I and phase II enzymes and metallothionein accumulation on sea bream Sparus aurata.

This research was designed to study Sparus aurata (sea bream) biotransformation and detoxification responses to acute exposure to cadmium (Cd). Sexually immature gilthead sea bream were treated by intraperitoneal injection of Cd chloride (200 microg kg(-1)) for 6, 12, 24 and 48 h. Cd accumulation was quantified in sea bream liver by graphite furnace atomic absorption spectroscopy after the various exposure periods. The following biological responses were measured: (1) ethoxyresorufin-O-deethylase (EROD) activity as phase I biotransformation parameter, (2) liver glutathione-S-transferase (GST) activity as a phase II conjugation enzyme and metallothionein (MT) content as specific response to Cd contamination. Cd bioaccumulation in the liver resulted in an increasing uptake up to 10.3 microg g(-1) wet weight after 48 h of exposure. EROD showed a significant activation only after 6 h exposure and a return to control levels after 12 h. GST revealed significant activation starting from 12 h exposure. MT accumulation in liver showed the same behavior as GST activation.