Smoking during pregnancy and its effect on placental weight: a Mendelian randomization study. - Jaitner, Annika; Vaudel, Marc; Tsaneva-Atanasova, Krasimira; Njølstad, Pål R.; Jacobsson, Bo; Bowden, Jack; Johansson, Stefan; Freathy, Rachel M. (BMC Pregnancy & Childbirth, 2024)