Maternal and newborn health in vegan and omnivore pregnancies: A prospective pilot study (PREGGIE)

13), as well as their newborns, in Germany (2019-2022). Maternal body mass index, weight and blood pressure were measured at gestational weeks 9-16 (t1) and 35-38 (t2). Additional assessments included maternal weight gain and excessive weight gain (from the beginning of pregnancy to t2), delivery method, gestational age, preterm birth, sex ratio, birth weight and length, small/large for gestational age, low birth weight, macrosomia, head circumference, and Apgar scores.SummaryNo significant differences were observed between the vegan and omnivore groups for any newborn outcomes, birth characteristics, or maternal health parameters. No preterm births occurred. Small for gestational age was observed in 2 vegan (6%) and 3 omnivore newborns (23%). Low birth weight (<2500 g) occurred in 1 vegan newborn (3%) and in no omnivore newborns. An Apgar score <10 at 10 min was recorded in 1 vegan (3%) and 1 (8%) omnivore newborn (both scoring 8).This study detected no clear adverse effects of a supplemented vegan diet (vitamin B12, iodine, vitamin D, omega-3 fatty acids) during pregnancy. Differences between vegans and omnivores cannot be excluded. The study was underpowered and baseline differences limit group comparability, validity, and generalizability. The study highlights key parameters and underscores the need to maximize group comparability in future research.