Please cite this paper as: Bergen N, Jaddoe V, Timmermans S, Hofman A, Lindemans J, Russcher H, Raat H, Steegers-Theunissen R, Steegers E. Homocysteine and folate concentrations in early pregnancy and the risk of adverse pregnancy outcomes: the Generation R Study. BJOG 2012;119:739–751. Objective To investigate associations between early pregnancy homocysteine, folate and vitamin B12 concentrations and placental weight, birthweight and adverse pregnancy outcomes. Design Population-based birth cohort study. Setting Rotterdam, the Netherlands. Population Cohort of 5805 pregnant women. Methods To analyse homocysteine, folate and vitamin B12 concentrations, blood was drawn in early pregnancy. These concentrations were divided into quintiles. Information on birth outcomes was retrieved from medical records. Multivariate regression analyses were used. Main outcome measures Placental weight, birthweight, small for gestational age at birth (SGA) (
