1 The Department of Pediatrics, School of Medicine, University of California, Los Angeles
2 The Department of Biophysics, School of Medicine, University of California, Los Angeles
3 The Department of Nuclear Medicine, School of Medicine, University of California, Los Angeles
The viscosity of amniotic fluid was measured in 52 ewes and the results correlated with the postnatal course of the lambs delivered by cesarean section. Viscosity was not related to length of gestation or to the immediate prepartum condition of the ewe, but a definite relationship was found between amniotic fluid viscosity (AFV) and the postnatal course of the fetus. Of 22 lambs considered viable, 9 failed to survive. In 10 of the 13 survivors, AFV was less than 1.6; whereas in the nonsurvivors, AFV varied between 1.6 and 4.4. All of the nonsurvivors experienced respiratory difficulty associated with copious amounts of extremely viscous secretions in the mouth and oropharynx.
The substance responsible for the high AFV was a mucoprotein and was detectable in all samples with a viscosity of 1.24 or more but in none with a viscosity below 1.24. The data suggest the possibility that fetal distress may induce qualitative or quantitative alterations of fetal mucous secretions in utero which subsequently could impede lung expansion at birth.
Submitted on March 14, 1966