Krueger WS, Anthony MS, Saltus CW, Margulis AV, Rivero-Ferrer E, Monz B, Hirst C, Wormser D, Andrews E. Evaluating the safety of medication exposures during pregnancy: a case study of study designs and data sources in multiple sclerosis. Drugs Real World Outcomes. 2017 Sep;4(3):139-49. doi: 10.1007/s40801-017-0114-9
Vardavas CI, Chatzi L, Patelarou E, Plana E, Sarri K, Kafatos A. Smoking and smoking cessation during early pregnancy and its effect on adverse pregnancy outcomes and fetal growth. Eur J Pediatr. 2010 Jun;169(6):741-8.