VP46.03: Screening for spontaneous preterm birth by cervical shear wave elastography and cervical length in the first trimester of pregnancy. Issue Volume 58:Issue S1(2021)Supplement (14th October 2021) - Feng, Q.; Duan, H.; Shen, L.; Wang, X.; Tai, Y.; Chaemsaithong, P.; Leung, T.; Poon, L.C.