1. Pregmama LLC , Gaithersburg, MD, USA
2. Department of Epidemiology and Public Health, University of Maryland School of Medicine , Baltimore, MD, USA
3. Department of Veterinary Integrative Biosciences, Texas A&M School of Veterinary Medicine , College Station, TX, USA
4. Present address: FHI 360, Durham, NC 27701, USA
5. Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Maryland School of Medicine , Baltimore, MD, USA