OBJECTIVE: In 2009, the National Children's Study (NCS) Vanguard Study tested the feasibility of household-based recruitment and participant enrollment by using a birth rate probability sample. In 2010, the NCS Program Office launched 3 alternative recruitment methods. We tested whether direct outreach (DO) recruitment could be a more efficient strategy to recruit women of child-bearing age. METHODS: The NCS DO recruitment approach recruited women, 18 to 49 years, who were pregnant or trying to conceive using passive recruitment methods emphasizing broad community outreach and engagement to create study awareness. Study mailings to listed households included a pregnancy screening questionnaire to identify potentially eligible women from selected neighborhoods to contact the study center. Unique features of this recruitment approach included the following: (1) expansion of selected neighborhoods to maximize potential participant recruitment and enrollment while minimizing in-person participant contact and (2) offering 2 levels of study participation distinguished by data collection intensity. RESULTS: Ten study centers listed 255 475 geographically eligible households for contact representing, on average, 3.3% of households per Primary Sampling Unit. A total of 19 354 women were identified for screening, and 17 421 completed a pregnancy screener representing 6.8% of eligible households. Study-eligible pregnant women were older, more educated, and less likely to be Hispanic than the general population. Only 16% (2786) of 17 421 screened women were study-eligible, and 81.1% of these 2786 women consented to participate. CONCLUSIONS: Although feasible, the DO approach recruited a sample of study-eligible pregnant women significantly different from the population. This recruitment approach was labor intensive for the yield of enrolled women.