3Christianson W T. Stillbirths, mummies, abortions, and early embryonic death [ J ]. Vet Clin North Am Food Animal Practice, 1992, 8(3): 623-623.
4Lucia J T, Corre^a M N, Deschamps J C, et al. Risk factors for stillbirth in two swine farms in the south of Brazil [ J ]. Preventive Veterinary Medicine, 2002, 53: 285-292.
5Sanders L M, Bilkei G. Urogenital diseases and their effect on reproductive performance in high-parity sows [ J ]. Tijdschr Diergeneeskd, 2004, 129(4) : 108-112.
6Borges V F, Bernardi M L, Bortolozzo F P, et al. Risk factors for stillbirth and foetal mummification in four Brazilian swine herds [ J ]. Preventive Veterinary Medicine, 2005, 70 : 165-176.
7Ahmed A, Dunk C, Ahmad S, et al. Regulation of placental vascular end othelial growth factor (VEGF) and placental growth factor (PLGF) and soluble Fit-1 by oxygen-a review [ J ]. Placenta, 2000, 21 (SupplA) : S16-24.
8Petersen M, Larsen T, Nielsen H J. Angiogenic proteins: possible Markers of physiopathological processes during fetal development [ J ]. Vgcskrlacgcr, 2003, 165 (32) : 3082-3087.
9Szukiewicz D, Szewczyk G, Watroba M, et al. Isolated placental vessel response to vascular endothelial growth factor and placenta growth factor in normal and growth-restricted pregnancy [ J ]. Gynecol Obstet In-vest, 2005, 59(2) : 102-107.
10Person R, Bodles-Brakhop A M, Pope M A, et al. Growth Hormone-releasing Hormone Plasmid Treatment by Electroporation Decreases Offspring Mortality Over Three Pregnancies [ J ]. Molecular Therapy, 2008, 16(11): 1891-1897.
