[1] Baylor Coll Med, Dept Pediat Cardiol, Houston, TX 77030 USA
[2] Univ S Florida, Coll Publ Hlth, Tampa, FL USA
[3] Texas Dept State Hlth Serv, Birth Defects Epidemiol & Surveillance Branch, Austin, TX USA
[4] UT Southwestern Med Cntr, Dept Pediat, Dallas, TX USA
[5] Baylor Coll Med, Dept Pediat, Houston, TX 77030 USA
[6] Baylor Coll Med, Cardiovasc Rsch Inst, Houston, TX 77030 USA