. Author manuscript; available in PMC: 2018 May 1.
Published in final edited form as: Am J Obstet Gynecol. 2017 Feb 7;216(5):512.e1–512.e9. doi: 10.1016/j.ajog.2017.01.042
This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/