title: Lecithin:sphingomyelin ratio in the amniotic fluid of male and female fetuses.
abstract: The effect of fetal sex on the amniotic fluid lecithin:sphingomyelin (L:S) ratio was determined with a prospective, randomized, double-blind study designed to evaluate the effect of antenatal steroid administration on the incidence of neonatal respiratory distress syndrome. The immature L:S ratios of 183 single births to nondiabetic women were analyzed. L:S ratios increased with increasing gestational age. Regression lines of L:S versus gestational age suggested that male infants' L:S ratios were lower than females', although the differences were not statistically significant.
authors.affiliation: Department of Pediatrics, University of Wisconsin Medical School, Madison.
authors.forename: R D
authors.initials: RD
authors.lastname: Zachman
authors.forename: J C
authors.initials: JC
authors.lastname: Morrison
authors.forename: L B
authors.initials: LB
authors.lastname: Curet
authors.forename: N
authors.initials: N
authors.lastname: Gustafson
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D011446:Prospective Studies; D011897:Random Allocation; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control*; D012737:Sex Factors; D013109:Sphingomyelins / Q000032:analysis*; D013256:Steroids / Q000627:therapeutic use*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins; D013256:Steroids