Objective To determine the association between congenital toxoplasmosis and preterm birth, low birthweight and small for gestational age birth.Design Multicentre prospective cohort study.Setting Ten European centres offering prenatal screening for toxoplasmosis.Population Deliveries after 23 weeks of gestation in 386 women with singleton pregnancies who seroconverted to toxoplasma infection before 20 weeks of gestation. Deliveries after 36 weeks in 234 women who seroconverted at 20 weeks or later, and tested positive before 37 weeks.Methods Comparison of infected and uninfected births, adjusted for parity and country of birth.Main outcome measures Differences in gestational age at birth, birthweight and birthweight centile.Results Infected babies were born or delivered earlier than uninfected babies: the mean difference for seroconverters before 20 weeks was - 5.4 days (95% CI: - 1.4, - 9.4), and at 20 weeks or more, - 2.6 days ( 95% CI: - 0.5, - 4.7). Congenital infection was associated with an increased risk of preterm delivery when seroconversion occurred before 20 weeks ( OR 4.71; 95% CI: 2.03, 10.9). No significant differences were detected for birthweight or birthweight centile.Conclusion Babies with congenital toxoplasmosis were born earlier than uninfected babies but the mechanism leading to shorter length of gestation is unknown. Congenital infection could precipitate early delivery or prompt caesarean section or induction of delivery. We found no evidence for a significant association between congenital toxoplasmosis and reduced birthweight or small for gestational age birth.

A new biotechnology has been developed which enables the incorporation of individual cells into intact tissue. In vivo experimentation has resulted in histologically modified animals (rabbits) which have received human cells into recipient corneal tissue. Quantitative methodology were developed to aid in control measures and to support analysis of experimental results. Investigation of various fusion parameters has guaranteed reproducibility but optimization of the fusion process remains to be completed. To expand the work into human oriented applications, full characterization of the electromagnetic field distribution inherent to the process is required as well as electrical characterization of human tissue.

In order to create unique animal models for biomedical research, our laboratory has worked out experimental procedures for the interspecies transfer of membrane surface components. Protocols were successfully developed to electrofuse individual human and nonhuman cells to rabbit corneal epithelial tissue. The individual cells are incorporated completely into the tissue within twenty minutes. We have demonstrated that both membrane bound gonococcal attachment receptors and human HLA class I antigens are present and are functional on the newly formed human-rabbit somatic cell hybrids. These results clearly demonstrate that cell-tissue electrofusion can be utilized to transfer human membrane components to intact animal tissue for the creation of clinically relevant animal models to study a variety of host specific infectious diseases.