Relationship Between Preterm Delivery and Salivary Estriol Level

Background and

Preterm birth accounts for 10 percent of total deliveries and is the most important cause of neonatal mortality. Levels of salivary estriol is, among others, an important indicator for early detection of preterm labor. This study carried out to determine the relationship between preterm delivery and estriol level in saliva.

This nested case-control study was conducted on 466 pregnant women referred to health centers in Sari from 2008 to 2010. Saliva was obtained and frozen from pregnant women during 25 to 34 weeks of gestation. Âfter sampling and follow up of women until childbirth, women with preterm delivery (58 cases) considered as case group. Âmong the rest of the subjects, 58 women were matched for mean age, educational level and body mass index (BMÏ) considered as control group. The saliva samples were melted and estriol level was measured.

There was no significant difference between the two groups regarding age, parity, educational level and BMÏ. However there were significant differences between the two groups for gestational age at the time of sampling (P<0.05), the time interval between taking saliva samples and delivery (P<0.05), weight gain during pregnancy (P<0.05), birth weight, (P<0.05) and employment (P<0.05). Ôdds Ratio showed a relationship between salivary estriol levels and preterm delivery [ÔR = 5.91, ÇÏ 95% (2.51-13.9)].Çonclusion: Çonsidering the high negative predictive value, it can be concluded that salivary estriol level has the potential to be used to identify women who are not at risk of preterm delivery, and unnecessary interventions can be avoided. Further researches are necessary for determining the role of estriol in prediction of preterm delivery.