1. Standardization of pregnancy loss terminology: Consensus of experts from the National College of Gynaecologists and obstetricians;Delabaere;J Gynécol Obstét Biol Reprod,2014
2. World Health Organization. Neonatal and perinatal mortality: national regional and Global estimates. Geneva: WHO; 2006.
3. National, regional and worldwide estimates of preterm birth;Blencowe;The Lancet,2012
4. Perrotin F, Lansac J, Body G. Strap placement in dealing with the threat of premature labor. J Gynecol Obstet Biol Reprod. 2002;31(7):5S66-5S73.
5. Perrotin F, Marret H, Ayeva-Derman M, et al. Second trimester therapeutic cervical cerclage: which technique is the most appropriate? A retrospectivestudy of 25 cases. J Gynecol Obstet Biol Reprod. 2002;31(7):640-648.