Relationship of Maternal and Fetal Plasma Ascorbic Acid Levels to Occurrence of Premature Rupture of Membranes.

Abstract

Low levels of blood ascorbate in pregnant women had been thought to have a role in incidence of premature rupture of membranes (PROM). In this study, maternal and fetal blood levels of ascorbate were surveyed in term and preterm labor. Each group was subdivided according to the presence of PROM. Placental ascorbate levels were also studied. Since ascorbate is known to be involved in the synthesis of collagen, hydroxyproline content of the amnion was also measured and taken as an index for collagen production. Amnionic membranes from births with PROM showed relatively low levels of hydroxyproline.Preterm newborns with PROM also exhibited a significantly low ascorbate concentration as compared with preterm controls. In conclusion, ascorbate in the fetal compartment appears to be important for the occurrence of PROM.

The Presence of Prolidase Activity in Amniotic Fluid and Its Evaluation as a Maturity Test

“…It has previously been shown that when the fetal growth rate is maximum, some metabo lites reach their value, and then remain at a steady state until the end of gestation [14][15][16], It is therefore possible that the high levels of prolidase activity between 32 and 37 weeks, when the growth rate is maximum, may be due to accelerated collagen turnover. High hydroxyproline levels accompanying the en zyme activity also support this hypothesis, since this amino acid is the product of proli dase action on collagen.…”

The Fetal Membranes and Mechanisms Underlying Their Labour-Associated and Pre-Labour Rupture During Pregnancy

“…164−166 This also provides a link with other behavioural factors such as smoking, which depletes systemic ascorbate levels. 167 However other studies have reported a specific association between PPROM and decreased ascorbate levels in fetal serum, placentae, 168 and in amniotic fluid, but not in maternal serum. 169 In this latter study dietary intake directly correlated with amniotic fluid levels but not with serum ascorbic acid levels.…”