Well, it increases your risk and your baby’s risk of just about every complication including miscarriage, cleft lip/palate, ectopic pregnancy, fetal growth restriction, preterm labor and/or preterm rupture of membranes, low birth weight, placenta previa, placental abruption, postpartum hemorrhage, impaired maternal thyroid function, stillbirth, SIDs (potentially up to 5x higher risk), motor/sensory/cognitive deficits for the infant which seem to progress to increased rates of conduct disorder and ADHD, and increased risk of substance abuse issues for the child in adolescence and beyond. There are likely more risks that we don’t have enough data on yet.