To document changes in birth rates, birth outcomes, and pregnancy risk factors among women giving birth after the 1997 Red River flood in North Dakota. We analyzed detailed county-level birth files pre-disaster (1994-1996) and post-disaster (1997-2000) in North Dakota. Crude birth rates and adjusted fertility rates were calculated. The demographic and pregnancy risk factors were described among women delivering singleton births. Logistic regression was conducted to examine associations between the disaster and low birth weight (<2,500 g), preterm birth (<37 weeks), and small for gestational age infants adjusting for confounders. The crude birth rate and direct-adjusted fertility rate decreased significantly after the disaster in North Dakota. The proportion of women giving birth who were older, non-white, unmarried, and had a higher education increased. Compared to pre-disaster, there were significant increases in the following maternal measures after the disaster: any medical risks (5.1-7.1%), anemia (0.7-1.1%), acute or chronic lung disease (0.4-0.5%), eclampsia (0.3-2.1%), and uterine bleeding (0.3-0.4%). In addition, there was a significant increase in births that were low birth weight (OR 1.11, 95% CI 1.03-1.21) and preterm (OR 1.09, 95% CI 1.03-1.16) after adjusting for maternal characteristics and smoking. Following the flood, there was an increase in medical risks, low birth weight, and preterm delivery among women giving birth in North Dakota. Further research that examines birth outcomes of women following a catastrophic disaster is warranted.