4Matthias Roth-Kleiner, Bendlcht Peter Wagnera, Denis Baehmanna, et al. Respiratory distress syndrome in near-term babies after caesarean section [J]. SWISS, 2003, 133: 283-288.
5Cho K, Matsuda I, Okajima S, et al. Factors influencing pulmonary surfactant protein a level in cord blood, maternal blood and amniotic fluid [J]. Biol Neonate, 1999, 75: 104-110.
6Levine EM, Ghai V, Barton JJ, et al. Mode of delivery and risk of respiralory dseases in newborns [J]. Obstet Gynecol, 2001, 97:439-442.