Background: The frequency and intensity of hurricane have increased greatly. However, whether hurricane exposure is associated with an increased risk of pregnancy complications is less known. Objective: To assess the immediate impact and lasting impact of Hurricane Sandy (Sandy) on pregnancy complications. Methods: Using time-series study, we estimated the relative risks (RRs) of emergency department (ED) visits for pregnancy complications in eight affected counties in New York State, based on data of 2005-2014. The immediate impact was estimated by comparing the ED visits of pregnancy complications during the Sandy period to the non-Sandy periods. For the lasting impact of Sandy, we estimated the RRs by contrasting the ED visits in the following 12 months after Sandy with the same months of other years. Results: We found that ED visits for overall pregnancy complications increased 6.3% (95% confidence interval (CI): 22%, 10.5%) during the Sandy month. ED visits increased for threatened abortion (9.9%, 95% CI: 4.4%, 15.7%), threatened labor (10.1%, 95% CI: 1.9%, 18.9%), early onset of delivery (115.9%, 95% CI: 6.9%, 336.3%), renal disease (732%, 95% CI: 0.3%, 199.4%), and diabetes (423%, 95% CI: 15.0%, 76.0%). Gestational hypertension and renal disease were elevated 7-8 months after Sandy. The ED visits of mental illness increased gradually after Sandy and peaked eight months later with visits increasing 332%. Conclusions: This study suggests that hurricanes may impact pregnancy health immediately and that some negative health may last for months thereafter.