5Meizner I, Katz M. Absence of significant hemodynemic changes in the fetus following maternal betamethasone administration[J]. Ultrasound Obstet Gynecol, 1997,10:223 - 225.
6Abbasi S, Hirsch D, Davis J, et al. Effect of single versus multiple courses of antenatal corticosteroids on maternal and neonatal outcome[J]. Am J Obstet Gynecol, 2000, 182:1243- 1249.
4Brody SC, Harris R, Lohr K. Screening for gestational diabe- tes: a summary of the evidence for the US preventive services task force [J] . Obstet Gynecol, 2003, 101 (2) : 380.
5Vollebregt A, van Hof DB, Exaho N. Prepidil compared to Propess for cervical ripening [J]. Eur J Obstet Gynecol Re- prod Biol, 2002, 104 (2): 116.