[1] Columbia Univ, Dept Obstet & Gynecol, Med Ctr, Div Maternal Fetal Med, New York, NY USA
[2] Columbia Univ Coll Phys & Surg, Med Ctr, Inst Human Nutr, 630 W 168th St, New York, NY 10032 USA
[3] Columbia Univ, Div Periodont, Coll Dent Med, Med Ctr, New York, NY USA
[4] Columbia Univ Coll Phys & Surg, Dept Microbiol & Immunol, Med Ctr, 630 W 168th St, New York, NY 10032 USA
[5] Columbia Univ Coll Phys & Surg, Dept Obstet & Gynecol, Med Ctr, New York, NY 10032 USA
[6] Columbia Univ Coll Phys & Surg, Dept Med, Med Ctr, New York, NY USA