[1] St Georges Univ London, St Georges Hosp, Fetal Med Unit, London, England
[2] Middle East Tech Univ, Fac Arts & Sci, Dept Stat, Ankara, Turkey
[3] Koc Univ, Sch Med, Dept Obstet & Gynaecol, Istanbul, Turkey
[4] Univ Edinburgh, Usher Inst Populat Hlth Sci & Informat, Edinburgh, Midlothian, Scotland
[5] St Georges Univ London, Mol & Clin Sci Res Inst, Vasc Biol Res Ctr, London, England
[6] Royal Coll Obstetricians & Gynaecol, London, England
[7] Univ Coll London Hosp NHS Fdn Trust, London, England
[8] Norfolk & Norwich Univ Hosp NHS Fdn Trust, Norfolk, VA USA
[9] North Bristol NHS Trust, Dept Womens Hlth, Bristol, Avon, England
[10] Univ Birmingham, WHO, Collaborating Ctr Womens Hlth, Inst Metab & Syst Res, Birmingham, W Midlands, England
[11] St Georges Univ London, Paediat Infect Dis Res Grp, London, England
[12] St Georges Univ London, Vaccine Inst, Inst Infect & Immun, London, England
[13] Publ Hlth England, Immunisat & Countermeasures Div, London, England
[14] Royal Coll Paediat & Child Hlth, British Paediat Surveillance Unit, London, England
[15] Kings Coll London, Inst Women & Childrens Hlth, Sch Life Course Sci, London, England