Serial studies of Serum Lipids in Normal Human Pregnancy**Presented at the Sixty-ninth Annual Meeting of the American Association of Obstetricians and Gynecologists, Hot Springs, Va., Sept. 4-6, 1958.

in vivo steroid biogenesis and metabolism in the human term placenta 2. in situ placental perfusion with cholesterol-7α-3H

“…Counting efficiencies were monitored utilizing standards prepared in the same manner as the samples. The values obtained in this study are somewhat lower than those found by de Alvarez et al (27). Sample size in the present study was small, and it is known that there is wide variation in maternal cholesterol levels.…”

“…The authors are unaware of other studies of paired umbilical arterial and venous samples. The concentration of cholesterol in the maternal compartment has been found to increase fromthe second trimester to term(27). This increase is present in both the free and esterified fractions.…”