Changes in 13, 14-dihydro-15-keto-prostaglandin F2alpha levels in saliva during pregnancy, labor and the postpartum period.

Aims: To examine changes in the levels of 13, 14-dihydro-15-keto-prostaglandin F(2alpha) (PGFM) in saliva during pregnancy, labor and the postpartum period, and to evaluate the relationship between cervical dilatation or contraction interval and salivary PGFM levels during labor.

Methods: This longitudinal study was conducted in the Department of Obstetrics in a hospital in Japan that has approximately 500 deliveries per year. Maternal and neonatal data were obtained from medical records. Saliva samples were collected during pregnancy (from 35 to 36 weeks gestation), labor and the postpartum period.

Results: Sixty-four healthy pregnant women were recruited and data from 30 subjects were analyzed. Salivary PGFM levels were almost constant during pregnancy, increased as labor progressed and decreased after delivery. Salivary PGFM levels during contraction intervals of 1-2 min were significantly higher than those when contraction intervals were 7-8, 5-6 or 3-4 min.

Conclusions: PGFM levels in saliva significantly increased with labor progression, remained at the highest level until delivery of the placenta, and decreased after delivery. Salivary PGFM levels are related not to cervical dilatation but to contraction interval. It was found that salivary PGFM levels reflected the contraction status of the uterus as delivery progressed.