Clinical validation of a closed vitrification system in an oocyte-donation programme.

Controversy exists about the risk of microbiological contamination from direct contact with unsterile liquid nitrogen during oocyte vitrification. The aim of this observational study was to evaluate the effectiveness of oocyte vitrification using a high-security closed vitrification system in a donation programme. Oocyte vitrification was performed using CBS High Security closed straws (Cryo Bio System) with DMSO/ethylene glycol/sucrose as the cryoprotectant (Irvine Scientific freeze kit).

Determinants of folic acid use in a multi-ethnic population of pregnant women: a cross-sectional study.

Aims: To investigate the possible differences in folic acid use and to identify the determinants of antenatal folic acid use among multi-ethnic pregnant women.

Methods: Three hundred and fifty pregnant women participated in this cross-sectional study in a university hospital in Brussels, Belgium. A questionnaire was used to obtain data on socio-demographic characteristics and folic acid use.

Otoacoustic emissions in a hearing conservation program: general applicability in longitudinal monitoring and the relation to changes in pure-tone thresholds.

The hearing status of workers (N = 233) in a printing office was assessed twice within seventeen months by pure-tone audiometry and otoacoustic emissions (OAEs). One of the questions was how a quality criterion of OAE-measurements based on a minimum signal-to-noise-ratio (SNR) would affect the applicability on the entire population. Secondly, effects of noise exposure were investigated in overall changes in audiogram and OAE-measurements.