Vuong, Ann M.; Shinde, Mayura U.; Brender, Jean D.; Shipp, Eva M.; Huber, John C; Zheng, Qi; McDonald, Thomas J.; Sharkey, Joseph R.; Hoyt, Adrienne T.; Werler, Martha M.; Kelley, Katherine E.; Langlois, Peter H.; Canfield, Mark A.; National Birth Defects Prevention Study