The glycocalyx is a gel-like layer covering the inside surface of all blood vessels. It is essential for normal flow and activity of the blood. Laboratory studies suggest damage to the glycocalyx increases risk of heart disease and pregnancy complications such as preeclampsia, gestational hypertension, gestational diabetes, small and large for gestational age and preterm delivery. Glycocalyx could be a valuable target for disease prevention and treatment. We do not have studies in large numbers of humans that use methods which could help us understand the causal effects of the glycocalyx. The clycocalyx can be measured in two ways: (i) measures in stored blood samples of molecules that are inside the glycocalyx but are shed into the blood when it is damaged (e.g. heparin sulphate proteoglycans, hyaluronic acid and syndecan 1 (SND1) and (ii) microscopic measurement of of small blood vessues under the tongue. We want to add both of these types of measurements to ALSPAC to improve our understanding of how the glycogalix could influence health and well being in pregnancy, during childhood and in adulthood.