Maternal obesity, overweight and hypertensive disorders are among the most important risk factors for complications during pregnancy. Several lines of evidence indicate that overweight or obese women, as well as women with hypertensive disorders show increased risks of preterm birth before 32 weeks. However, an easy to determine, common reliable prognostic factor which allows for the early identifications of risk patients is still lacking. Recently, it has been reported that assessment of endothelial function may be a new promising tool for predicting the risk of adverse pregnancy outcome. As such evidence has been provided that endothelial dysfunction is prevalent among women with preeclampsia and is able to identify women at increased risk of preterm delivery and small-for-gestational-age (SGA) births. Several lines of evidence indicate that functional and structural changes of retinal vessels are altered in vascular related disease and may predict cardio-vascular events. Consequently, the current study seeks to investigate whether flicker induced vasodilatation, a well established parameter to test vascular function in-vivo is altered in women with low and high risk pregnancies when compared to a healthy control group. The data gained from this study may provide the basis for a larger longitudinal trial to assess whether vascular changes in the retina may predict the risk for complication during pregnancy.