IM Spence-Lewis MD, 21 May 2018 https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-016-0986-9
IM Spence-Lewis MD, 22 Mar 2017 https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-016-0986-9