[1] Spectrum Hlth, Div Pulm & Crit Care Med, Pulm Hypertens Program, Grand Rapids, MI 49503 USA
[2] Michigan State Univ, Coll Human Med, Grand Rapids, MI 49503 USA
[3] Spectrum Hlth, Dept Obstet & Gynecol, Maternal Fetal Med, Grand Rapids, MI USA
[4] Spectrum Hlth, Obstet Anesthesia, West Michigan Anesthesiol, Grand Rapids, MI USA