1. Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine; National University of Singapore; Singapore S119228
2. Department of Obstetrics and Gynaecology, Nanfang Hospital; Southern Medical University; Guangzhou 510515 China
3. Cancer Science Institute of Singapore; National University of Singapore; Singapore S117599
4. Department of Laboratory Medicine, Molecular Diagnosis Centre; National University Hospital; Singapore S119074
5. Experimental Fetal Medicine Group, Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine; National University of Singapore; Singapore S119228
6. Department of Reproductive Medicine; KK Women's and Children's Hospital; Singapore S229899
7. Department of Paediatrics, Yong Loo Lin School of Medicine, National University Hospital; National University of Singapore; Singapore S119074