[1] Oregon Hlth & Sci Univ, Dept Obstet & Gynecol, Portland, OR 97201 USA
[2] Univ Calgary, Cumming Sch Med, Dept Obstet & Gynecol, Calgary, AB, Canada
[3] Washington Univ, Dept Obstet & Gynecol, St Louis, MO USA
[4] Sheffield Teaching Hosp Trust, Royal Hallamshire Hosp, Glossop Rd, Sheffield, S Yorkshire, England
[5] Univ Cent Florida, Orlando, FL 32816 USA
[6] Karolinska Inst, Dept Clin Sci Intervent & Technol, Div Pediat, Stockholm, Sweden
[7] Karolinska Inst, Dept Clin Sci Intervent & Technol, Div Obstet, Stockholm, Sweden
[8] Royal Surrey Cty Hosp, Dept Anaesthesia, Egerton Rd, Guildford, Surrey, England
[9] Alzahra Hosp, Dept Anesthesiol, Dubai, U Arab Emirates
[10] Alzahra Hosp, Dept Intens Care, Dubai, U Arab Emirates
[11] Univ Alberta, Dept Med, Edmonton, AB, Canada